3rd international symposium on nanoscience and nanomaterials

CNyN-UNAM GENERAL PROGRAM

GENERAL PROGRAM

3rd International Symposium on Nanoscience and Nanomaterials

Ensenada, Baja California, Mexico, March 10-14, 2014

Universidad Nacional Autónoma de México

Centro de Nanociencias y Nanotecnología


ORGANIZING COMMITTEE

Dr. Gustavo A. Hirata

Dr. Oscar E. Contreras

Dr. Olivia Graeve

Dr. Ma. de la Paz Cruz

Dr. Felipe F. Castillón

Dr. Rubén D. Cadena

Lic. Margot Sainz R.

GRAPHIC DESIGN

LDG. Marina Curiel

Dr. Mario Curiel

EDITING

G.A. Hirata

Prakhar Sengar

Akhil Jain


CONFERENCE TOPICS

Bionanotechnology

Structural properties of nanomaterials

Electronic, optical and transport properties of nanostructures

Nanomagnetism and spintronics

Micro and nanoelectromechanical systems (MEMS/NEMS)

Carbon and related systems

Quantum computing

Surfacess and interfaces

Thin films

Synthesis of nanomaterials

Nanocatalysis


SPEAKERS

Mario F. Borunda

OKLAHOMA STATE UNIVERSITY

Olivia A. Graeve

UNIVERSITY OF CALIFORNIA, SAN DIEGO

Alexander Orlov

STONY BROOK UNIVERSITY

J. E. Garay

UNIVERSITY OF CALIFORNIA, RIVERSIDE

Rommie E. Amaro

UREY HALL, LA JOLLA, CALIFORNIA.

Milan Makale

UNIVERSITY OF CALIFORNIA, SAN DIEGO

Charles M. Knobler

UNIVERSITY OF CALIFORNIA, LOS ANGELES.

Bogdan Dragneaa

INDIANA UNIVERSITY BLOOMINGTON


Jose Antonio Eiras

Universidade Federal de Sao Carlos

Ravi Droopad

INGRAM SCHOOL OF ENGINEERING, TEXAS STATE UNIVERSITY, SAN MARCOS

Joanna McKittrick

UNIVERSITY OF CALIFORNIA SAN DIEGO

Miguel JoseYacaman

UNIVERSITY OF TEXAS AT SAN ANTONIO

Bhabendra Pradhan

CTO, NANOHOLDINGS LLCCOUNTRY

ROWAYTON, CT, USA

Manuel Quevedo

UNIVERSITY OF TEXAS, DALLAS

Raymundo Arróyave

TEXAS A&M UNIVERSITY


WEEK SCHEDULE

3rd International Symposium on Nanoscience and Nanomaterials March 10-14, 2014 - Ensenada, Baja California, Mexico

Time Monday10 Tuesday 11 Wednesday 12 Thursday 13 Friday 14 8:00 – 9:00 Registration 9:00 – 9:20 Inauguration

3rd

Meeting

of

Multidisciplinary

Inter-

Institutional

International

Network

9:20 – 10:00 Plenary I Mario Borunda

Plenary V Rommie Amaro

Plenary IX Jose A. Eiras

Plenary XII Miguel

Yacaman

10:00 – 10:20 Talk 1 Elena

Smolentseva Plenary VI Milan Makale

Talk 17 Luis Fuentes Plenary XIII

Bhabendra Pradhan

10:20 – 10:40 Talk 2 Brenda Acosta

Talk 18 Jesús Siqueiros

10:40 – 11:00 Talk 3

Viridiana Evangelista

Talk 9 Lorena Sánchez

Talk 19 Jesús Heiras

Talk 23 Víctor García

11:00 – 11:20 Talk 4 Andrey

Simakov

Talk 10 Rees Garmann

Talk 20 José Romo

Talk 24 James Kelly

11:20 – 11:40 Coffee Break

11:40 – 12:20 Plenary II Olivia A. Graeve

Plenary VII Charles Knobler

Plenary X Ravi Droopad

Plenary XIV Manuel

Quevedo

12:20 – 13:00 Plenary III Alexander

Orlov

Plenary VIII Bogdan Dragnea

Plenary XI Joanna

McKittrick

Plenary XV Raymundo Arróyave

13:00 – 13:20 Talk 5 Karla Juárez

Talk 11 Miguel Méndez

Talk 21 Héctor Sánchez

Talk 25 Mufei Xiao

13:20 – 13:40 Talk 6 Cristina Torres

Talk 12 Katya

Novistkaya

Talk 22 Manuel Herrera

Talk 26 Amir

Maldonado

13:40 – 14:00 Talk 7 Rafael Navarro

Talk 13 Roberto Vazquez

Photograph Talk 27

Hugo Tiznado

14:00 – 16:00 Lunch

16:00 – 16:20 Plenary IV Javier Garay

Talk 14 Oscar Jaime

Free time

Poster Exhibition II

16:20 – 16:40 Talk 15 Rey García

16:40 – 17:00 Talk 8 Néstor Perea

Talk 16 Catalina López

17:00 – 18:00 Welcome Cocktail

Poster Exhibition I 18:00 – Closing


FORMAT RESTRICTION OF ABSTRACTS

The proceedings of 3rd International Symposium on Nanoscience and Nanomaterials are a compilation of the accepted abstracts of the plenary, contributed oral and poster presentations. Due to format restrictions figures and cited reference, although mentioned in the abstract, were not included in the printed version. If you require additional information please write to the authors.


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PLENARY SESSION

PLENARY I

QUANTUM CONTROL AT THE NANOSCALE:

MANIPULATING ELECTRONS FOR QUANTUM INFORMATION

Mario F. Borunda1

1Oklahoma State University, Stillwater, OK, 74074 USA

[email protected]

Keywords: Quantum Control, Quantum Information, Nanostructures.

The quest for solid-state quantum computing in semiconductor nanomaterials has led to break

through in the initialization, processing, and readout of single- and two-particle states in coupled quantum

dots. Fast and accurate control of electronic states is a key requirement for solid-state quantum

information processing.I will present theory and calculations for coherent high-fidelity quantum control

of many-particle states and for the local control of electronic charge. Coupling a two-electron double

quantum dot to a terahertz optical source enables targeted excitations that are one to two orders of

magnitude faster and significantly more accurate than those obtained with electric gates. I will also

present the idea of local optimal control theory as a powerful approach to find optimized gate voltages

that induce coherent transitions between electronic states. The proposed schemes achieve (i) faster

operation time and (ii) limits the frequencies used in the control fields to the experimentally accessible

range, while maximizing the fidelity of the processes. The ability to coherently control arbitrary two-

electron states to maximize their entanglement and coherently manipulate charge states opens up further

opportunities in nanoscience and represents a clear advancement in solid-state quantum information.

PLENARY II

CORRELATION BETWEEN PARTICLE SIZE AND SINTERING BEHAVIOR OF NANOPOWDERS

Olivia A. Graeve

Olivia A. Graeve1,2,a, James T. Cahill,1,b Hoorshad Fathi,2,c James P. Kelly1,2,d

1Department of Mechanical and Aerospace Engineering, University of California, San Diego 9500 Gilman Drive – MC 0411, La Jolla, CA 92093-0411, USA

2Kazuo Inamori School of Engineering, Alfred University ,Pine Street, Alfred, NY 14802, USA

[email protected], [email protected], [email protected], [email protected]


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Keywords: Triboluminescence, nanopowders, coatings, crack detection, combustion synthesis, structural

health monitoring.

We present an overview of fundamental responses and limits of precipitation processes for the

synthesis of nanostructured ceramic nanopowders, with special emphasis on combustion synthesis for the

preparation of borides and reverse micelle synthesis for the preparation of oxides. Advanced sintering

techniques for nanostructured materials will also be described and a correlation between powder particle

size and sintered grain size will be presented. Boride compounds have proven essential for myriad

applications such as reinforcing phases in metal-matrix composites and armor materials. One particular

sub-group in this large class of materials includes the hexaborides. We will demonstrate the first instance

of the preparation of boride materials by the efficient combustion synthesis technique at a temperature of

320°C. We will also present an analysis and systematic investigation of the structure and stability of

reverse micelle systems with the addition of NH4OH, ZrOCl2, and Al(NO3)3 salts. The concept of an

electrical double layer, as it applies to reverse micelles, will be considered for explaining features of

destabilization, including the initial decrease in reverse micelle size, the destabilization concentration, and

the effect of cation valence. We propose that the reduction in size prior to instability is caused by

compression of the reverse micelle electrical double layers, as higher concentrations of salts are present.

All these effects have important implications for the preparation of nanopowders by reverse micelle

synthesis. If the reverse micelles are unstable before the precipitates are formed then the advantage of

reverse micelle synthesis is immediately lost.

PLENARY III

STUDIES OF SUPPORTED NOBLE METAL NANOPARTICLES FOR SUSTAINABLE FUELS PRODUCTION

Alexander Orlov1,a, Peichuan Shen1 , Yan Li2 and Shen Zhao1

1Materials Science and Engineering, Stony Brook University, Stony Brook, NY 11794, USA

2Computational Science Center, Brookhaven National Laboratory, Upton, NY 11973, USA

[email protected]

Keywords: Nanoparticles, catalysts, photocatalysis, noble metals

Understanding the role of noble metal nanoparticles in production of H2 under light under solar

light is a growing area in sustainable energy research. Although there are numerous studies of using these

metals as co-catalysts, the issues related to a size range where they lose their metallic properties is a very

promising area of investigation. In this study we combine experimental studies of primarily Pt based


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catalysts with DFT calculations, where we explore the issues related to shape and size of these

nanoparticles. More specifically, we utilize microscopy, spectroscopy and reactor studies to understand

the advantages of using nanometer and sub-nanometer particles for photocatalytic water splitting and

water gas shift reactions. The results obtained for Pt nanoparticles will be compared to data obtained for

other noble metal catalysts.

PLENARY IV

PROCESSING OF NANOCRYSTALLINE TRANSPARENT CERAMICS FOR PHOTONIC APPLICATIONS

E. H. Penilla1, A. T. Wieg1, C. L. Hardin1, Y. Kodera1 and J. E. Garay1a

1Materials Science and Engineering Program and Mechanical Engineering

University of California, Riverside

[email protected]

Keywords: Photonic materials, ceramics, nanocrystalline.

It is well known that microstructure can significantly affect the optical properties of

polycrystalline ceramics. For example, holding the grain and pore sizes to length scales less than the

wavelength of light can be significantly increase transparency. Recently, the versatile material processing

technique of current activated pressure assisted densification (CAPAD), often called Spark Plasma

Sintering (SPS) has been gaining momentum as a tool for producing optical ceramics. The primary reason

is that CAPAD is especially effective in overcoming the grain growth challenge. Additionally, there is

now evidence that the technique is capable of producing non-equilibrium ceramics, i.e. materials that

cannot be made using conventional sintering. The method draws its effectiveness from large electric

current densities that serve to heat the materials and can also alter the processing kinetics. After an

overview of our processing techniques, we will present results from ongoing work on tailoring the optical

properties of oxide and nitride ceramics. We will discuss results showing improved visible light

transmittance and luminescence and will also show efforts on fabricating near net shaped ceramics.


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PLENARY V

ENABLING CHEMICAL DISCOVERY THROUGH THE LENS OF A COMPUTATIONAL MICROSCOPE

Rommie E. Amaro1a

13234 Urey Hall, La Jolla, California, 92093-0340, United States

[email protected]

Keywords: molecular biophysics, drug discovery, rational design, cancer, p53

With exascale computing power on the horizon, computational studies have the opportunity to

make unprecedented contributions to drug discovery efforts. Steady increases in computational power,

coupled with improvements in the underlying algorithms and available structural experimental data, are

enabling new paradigms for discovery, where in computationally predicted ensembles from large-scale

biophysical simulations are being used in rational drug design efforts. Such investigations are driving

discovery efforts in collaboration with leading experimentalists. I will describe our work in this area that

has provided key insights into the systematic incorporation of structural information resulting from state-

of-the-art biophysical simulations in to protocols for inhibitor and drug discovery, with emphasis on the

discovery of novel druggable pockets that may not be apparent in crystal structures.

PLENARY VI

NANOTECHNOLOGY DERIVED STRATEGIES AS POTENTIAL TREATMENTS FOR CENTRAL NERVOUS SYSTEM TUMORS

Milan Makale

University of California San Diego, Moores Cancer Center, 3855 Health Sciences Drive

La Jolla, CA, USA, 92093

[email protected]

Keywords: Radiotherapy; nanoparticle; cancer.

Standard chemo-radiotherapy falls far short in the most common and lethal forms of brain

cancer in adults and children. These tumors are often distressingly resistant to radiation and

chemotherapy, and these standard protocols induce profound life-long morbidity in the few surviving

patients. We believe there are two key issues in translational brain cancer research which are linked to

the stubborn resistance of this tumor; (1) potent anti-tumor agents able to overcome resistant brain tumors

in culture have fared poorly in preclinical development because of pharmacokinetic, toxicity, and

targeting limitations, and (2) megavoltage radiotherapy of the brain and spinal cord is an extremely useful


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mainstay and palliative measure, but the required doses are too high, causing severe normal tissue

damage.

PLENARY VII

IN-VITRO SELF-ASSEMBLED PLANT VIRUS-LIKE PARTICLE VECTORS

FOR MAMMALIAN CELLS

Charles M. Knobler

Department of Chemistry and Biochemistry, University of California, Los Angeles, CA USA

[email protected]

Keywords: In vitro assembly, plant viruses, RNA packaging, gene delivery

The Cowpea Chlorotic Mosaic Virus consists of a protein shell called the capsid made up of 180

identical proteins that surrounds and protects the genome, 3,000 nucleotide-long single-stranded positive-

sense RNA. Remarkably, the virus is capable of self-assembling when the pure RNA and pure protein are

mixed in an appropriate buffer solution. More remarkable still, the capsid can assemble around non-viral

RNAs, ranging in length from 100 to 10,000 nt, as well as anionic polymers, quantum dots and nano-

emulsion droplets. This capacity to package a wide variety of cargoes can be utilized for delivery of

genetic information to cells as demonstrated by recent experiments [Azizgolshani, et al. “Reconstituted

Plant Viral Capsids Can Release Genes to Mammalian Cells,” 2013Virol. 441, 12 – 17] that this plant

virus can be employed for transfection of mammalian cells.

PLENARY VIII

ON THE ORIGIN OF INCOMPLETENESS IN IMMATURE HIV-GAG PARTICLES

Bogdan Dragnea

Chemistry Department Indiana University Bloomington, IN 47408, U.S.A.

[email protected]

Keywords: Self-assembly, HIV, virus assembly, nanoparticle, electron microscopy.

To understand and interfere with the stages of the virus life cycle, knowledge of the structural

properties of viruses and their assembly intermediates is required. A case in point is the human

immunodeficiency virus type 1 (HIV-1), which, despite intense study, still presents challenges coming

from a limited knowledge of its architecture and the transformations associated with its passage from the

noninfectious immature state to the infectious mature state during the viral life cycle. An intriguing

feature of the immature HIV-1 is the sizable gaps in its protein lattice observed by electron microscopy.

The origin of the gaps is not understood but they may be important for the timing of release of the viral


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particle from the cellular membrane before assembly is completed. We hypothesize that the gaps are

unavoidable consequences of the high aspect ratio of the protein subunits constrained to assemble on a

spherical shell. We present experiments testing this hypothesis by nanoparticle directed assembly.

PLENARY IX

HT SINGLE PHASE MULTIFERROICS

José Antonio Eiras

Universidade Federal de São Carlos - Departamento de Física

Grupo de Cerâmicas Ferroelétricas - CEP 13565-670 - São Carlos - SP – Brazil

[email protected], [email protected], [email protected]

Keywords: Magnetoelectric coupling (ME).

In the last decade, intensive research efforts have been devoted to produce magnetoelectrics

materials viewing to improve the electric control of the magnetization and vice-versa at high

temperatures. Among the materials with potential characteristics to present improved magnetoelectric

coupling (ME) arise the single phase multiferroics (SPM), that present the coexistence of electric and

magnetic ordering below characteristics temperatures. The cross-coupling between the magnetic and

electric orders parameter, termed magnetoelectric coupling, brings novel physical phenomena and offers

potential ability to control or sense the material polarization or magnetization states with either magnetic

or electric field. This opens possibilities to develop devices (transducers, sensors, actuators…) for new

technological applications. The main challenge for practical application of SPM lies in the difficulty to

obtain materials with multiferroics characterisitics around room temperature. Typical lead based

perovskites that can present multiferroics ordering are Pb(Fe1/2Nb1/2)O3 and Pb(Fe2/3W1/3)O3. Reports

related to these materials attributed the magnetic ordering to the Fe3+ ions, while the ferroelectric ordering

was related to the W6+ or Nb5+ ions. In this presentation experimental results of Pb(Fe1/2Nb1/2)O3 and (1-

x)Pb(Fe2/3W1/3)O3– xPbTiO3 (PFWPT) (0≤ x≤ 0.30) ceramics, viewing to the establishment of the

magnetoelectric coupling around room temperature will be presented. The temperature intervals where

ferroelectric or magnetic ordering occurs and coexists and the characteristics of the magnetoelectric

coupling were investigated through magnetic, dielectric spectroscopy and anelastic measurements as a

function of the temperature. Evidences of changes in magnetic ordering (above 500 K) and the presence

of magnetoelectroelastic anomalies (in the temperature range of 200k to 300 K), will be discussed.


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PLENARY X

INTEGRATION OF FUNCTIONAL OXIDES WITH SEMICONDUCTORS

Ravi Droopad1, a, R. Contreras-Guerrero1, Hanu Arava1, J. Rojas Ramirez1, Robert Klie2, Jeremy Levy3, Byounghak Lee1

1Ingram School of Engineering, Texas State University, San Marcos, TX 78666

2Dept. of Physics, University of Illinois-Chicago, Chicago, IL 60607

3Dept. of Physics and Astronomy,University of Pittsburgh, Pittsburgh, PA 15260

4Dept. of Physics, Texas State University, San Marcos, TX 78666

[email protected],

Keywords: Epitaxial oxides, molecular beam epitaxy, semiconductors.

Oxides have played an important role in the creation of the transistor leading to the proliferation

of modern day consumer electronics. In this application the oxide layer is amorphous, act as a dielectric

with low leakage, and has a high quality interface that is only possible with silicon. Crystalline oxides on

the other hand possess rich and diverse properties that can be exploited to create novel functional devices

when integrated with other semiconductors. One such example is the use of ferroelectric layers to perturb

the 2 dimensional electron gas channels in III-V semiconductors leading to reconfigurability of high

speed optoelectronic devices. Another is the use of magnetic layers on semiconductors to fabricate spin

transport devices and novel non-volatile memories. However the challenge is the integration of these

crystalline oxide materials, and controlling the interface quality, with semiconductors. With the recent

advances in oxide molecular beam epitaxy, high quality functional oxides with near perfect interface can

now be grown. In this presentation, I will outline the growth of these crystalline oxides on both silicon

and GaAs which demonstrate functionality. Bonding chemistry at the oxide/semiconductor

heterointerfaceis also investigated in an attempt to understand the atomic structure of such interfaces.

PLENARY XI

NANOSCALE EFFECTS ON THE MECHANICAL PROPERTIES OF BIOLOGICAL MATERIALS

Joanna McKittrick

Department of Aerospace and Mechanical Engineering and Materials Science and

Engineering Program

University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92037, USA

[email protected]

Keywords: Biological materials, mechanical properties


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Structural biologicl materials such as mollusk shells and bone are light weight, strong and

fracture resistant. Due to the hierarchical structure of these materials, each level presents a strengthening

and toughening mechanism. At then at nanoscale, features such as sacrificial bonds, bridges and

viscoelastic stretching are present. This presentation will discuss how these features operate and interact

to result in these extraordinary properties of biological materials.

PLENARY XII

WHAT IS NEXT IN HIGH RESOLUTION ELECTRON MICROSCOPY

IN NANOTECHNOLOGY?

Miguel JoseYacaman

University Of Texas at San Antonio, PhysicsDepartment

[email protected]

Modern electron microscopy has achieved an old dream to break the 1A resolution barrier.

Indeed Microscopes such as the ARM in UTSA have a resolution of 0 .8 A (80 pm) that can be achieved

in a routine basis. Our microscope was the number one in the world until recently the DOE center at

Berkeley achieved 0.5 A. In real terms since the size of the atom is in that range (Helium atom is 40 pm)

it means that the resolution that we have achieved is the limit of can be achieved. Below the nuclear

interactions will dominate and other phenomena will dominate. So what is the Future of Electron

Microscopy? It can be say that from now on all the improvements will be not in resolution but in other

areas. In this talk we will review the most significant areas of nanotechnology that demand significant

improvements in Electron microscope techniques. Some examples are the need of more accurate in situ

experimentation and measurements, single electron detection, need of low voltage and many others.

PLENARY XIII

COMMERCIALIZATION OF NANOTECHNOLOGY INNOVATION AT UNIVERSITY: CONCEPT TO PRODUCT

Bhabendra Pradhan

CTO, Nanoholdings LLCcountry

Rowayton, CT, USA

[email protected]

Keywords: List the keywords that best describe the contents of your paper.

One of the biggest challenges for our society is to find ways provide energy needed for our

growing demand, and at the same time preserves our eco-system. Nanotechnology can contribute a


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positive development in this direction in several ways. University’s leading scientists invent many new

technologies at universities laboratory. Of ten university inventions fall in the “innovation gap” which

refers to the difficulty of obtaining capital to develop the technology further for commercialization or

materializing these new concepts into a viable product. This talk will discuss finding promising new

university innovations and starting new companies to develop and commercialize them. Nanoholdings is a

company whose business model is to fill this gap for energy and wáter related nanotechnologies. Several

examples will be discussed which represent technology developments and commercialization at different

university worldwide that have enormous potential.

PLENARY XIV

OXIDE AND II-VI MATERIALS ENABLING NOVEL DEVICES FOR FLEXIBLE AND LARGE AREA ELECTRONICS

Manuel Quevedo

Department of Materials Science and Engineering, University of Texas, Dallas

[email protected]

Keywords: Radiation detectors, II-VI, Thin Film Transistors, Electrical Performance

Low temperature device technologies that have enabled flexible displays also present

opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible

applications in flexible, low metal content, sensor systems for unattended ground sensors, smart medical

bandages, electronic ID tags for geo-location, conformal antennas, neutron/gamma-ray/x-ray detectors,

etc. In this talk, our efforts to develop novel inorganic semiconductor materials based on oxides and II-VI

systems for novel CMOS integration schemes, circuits, memory, sensors as well as advanced metal

contacts, dielectrics and semiconductors for flexible electronics are presented. In particular, we discuss

fundamental materials properties including crystalline structure, interfacial reactions, doping, etc. defining

device performance and reliability of inorganic oxides and II-VI materials. Materials characterization

methods including RBS, XPS, XRD, etc. are used to analyze materials deposited by pulsed laser

deposition, chemical bath deposition and inkjet printing. With the materials developed here thin film

transistors (TFTs) with mobility’s as high as ~30 cm2/V s, Ion/Ioff of ~109 and VT shift of less than ~0.1

eV are demonstrated. To achieve these TFTs characteristics, a variety of contact materials, gate dielectric,

annealing conditions and device structures were studied. The factors affecting VT instability are also

presented and correlated to electrode materials, gate dielectric, and post-annealing conditions. In short,

TFT instability is correlated to traps and impurities at the dielectric/semiconductor and/or semiconductor

film. In addition, integration of these TFTs in CMOS circuits is demonstrated. In particular, a variety of

logic gates and FRAM memory cells are demonstrated. The feasibility of II-VI and oxides for flexible


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and transparent devices as well as novel radiation sensors is discussed. Finally, we demonstrate an

integrated neutron sensor fully fabricated at UT-Dallas that includes wireless communication to a mobile

device.)

PLENARY XV

PHASE STABILITY IN MULTILAYERED THIN FILMS

Raymundo Arróyave1,2,a , Anchalee Junkaew1,b ,Byoungsoo Ham2,c ,

1Department of Materials Science and Engineering, Texas A&M University, USA

2Department of Mechanical Engineering, Texas A&M University, USA

[email protected], [email protected], c [email protected], [email protected]

Keywords: Nano-films, phase stability, thermodynamics

On the basis of the underlying thermodynamic constraints, phase stability of constituents in

metallic multilayer thin films can be markedly different from the stability of the same material in bulk

form. In the absence of size effects, metastable (and even unstable) phases can only be stabilized in bulk

form under further constraints, such as elevated-pressures and temperatures. On the other hand, interfacial

effects resulting from the growth of nanolayer systems has been shown to stabilize these metastable

phases under ambient conditions, albeit under coherency constraints arising from the epitaxial growth of

these films. The stabilization of these so-called pseudomorphic phases results from the competition

between bulk and interfacial contributions to the free energies of the multilayer systems. In this work, a

classical thermodynamic approach has been used for describing the pseudomorphic growth in Mg/Nb

multilayer films. The bi-phase diagram of these films has been predicted theoretically and the predictions

were verified experimentally by growing multiple Mg/Nb thin films that were characterized through high

resolution transmission electron micrograph (HRTEM) and X-ray diffraction (XRD) measurement. The

good agreement between predictions and experiments shows that the stability of multilayer films can be

explained through simple thermodynamic analysis on the competition between bulk and interfacial

energies.

ORAL SESSIONS


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O-001

FTIR study of benzyl alcohol and benzaldehyde adsorption on Au/Ce-Al-O catalysts

Elena Smolentseva1, a, Sergey Beloshapkin2,b, Elena V. Gusevskaya3,c, Sergio Fuentes1,d and Andrey Simakov1,e

1 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, km.107 carr. Tijuana a Ensenada, C.P. 22860, Ensenada, B.C., México

2 Materials & Surface Science Institute, University of Limerick, Limerick, Ireland

3 Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil

[email protected],[email protected],[email protected],[email protected],[email protected],

Keywords: Gold catalysts, FTIR, benzyl alcohol, benzaldehyde.

The oxidation of alcohols is an important goal for synthetic organic chemistry. Gold catalyzed

oxidation of alcohols, which involve O2 as an oxidant, is a good option because it is cheap, safe and

produces only water as a by-product. The catalytic efficiency of gold catalysts depends on the size of Au

nanoparticles and the affinity of the support to stabilize key reaction components. The present work was

dedicated to the FTIR study of benzyl alcohol and benzaldehyde adsorption on the gold catalysts

supported on Ce-Al-O mixed oxides, alumina and ceria as well. Gold catalysts (3 wt.%) were prepared by

deposition-precipitation with urea and activated in oxygen or in hydrogen at 350ᵒC. Samples were

characterized by FTIR, XPS, in situ UV-Visible spectroscopy and TEM. It was revealed that the nature of

adsorbed complexes and their stability are determined by the nature of supports and type of catalyst redox

pretreatment. The data obtained are in a good correlation with the catalytic activity and selectivity of

these gold catalysts in aerobic oxidation of benzyl alcohol. The authors thank to E. Flores, P. Casillas,

V.García, F.Ruiz, E.Aparicio, M. Sainz and J. Peralta for their kind technical support in this work. The

financial support from CNPq, FAPEMIG and INCT-Catálise (Brazil), CONACyT (Mexico) and

DGAPA–PAPIIT (UNAM, Mexico) through the grants 179619 and 203813, respectively, and SENER-

CONACyTby grant 117373.

O-002

ACTIVITY OF Au-Pd BIMETALLIC NANOREACTORS IN CATALYTIC REDUCTION OF NITROPHENOLS

Brenda Acosta1,a, Viridiana Evangelista1,b, Sergio Fuentes2,c and Andrey Simakov2,d

1Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, B.C., 22860, México.


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2Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México (CNyN- UNAM), Ensenada, BC, 22860, México.

[email protected]

Keywords: Nanoreactors, Encapsulation, Au-Pd nanoparticles, Nitrophenol, SiO2 and ZrO2.

In the last few years, the encapsulation of catalytically active nanoparticles with formation such

structures as nanoreactors has become very attractive due to their high stability against the reaction

conditions. In order to enhance the catalytic performance of these nanoreactors, the encapsulation of

bimetallic nanoparticles has been proposed. The nanoreactors based on Au-Pd nanoparticles are very

promising because these nanoparticles are characterized with high efficiency in the multiple reactions of

fine and environmental chemistry. However, till now only Au-Pd encapsulated in silica (AuPd@SiO2)

and tested in CO oxidation have been reported. On the other hand, the reduction of nitrophenol into

aminophenol, the most common reaction for test of nanoreactors, is relevant by two main reasons: (i)

hydrogenation of nitro-compounds helps with the environmental pollution; and, (ii) the product,

aminophenol, is useful in pharmaceutical industry and photographic. Therefore, here is reported the

design of AuPd@ZrO2 nanoreactors with yolk shell structure and test of their activity in the catalytic

reduction of nitrophenols. The proposed AuPd@ZrO2 nanoreactors, successfully prepared via the

traditional bottom-up route, were characterized with a mono dispersion of Au-Pd cores inside the

inorganic shells. The porous structure of the ZrO2 shells allows free transport of nitrophenol and

aminophenol during the reaction. Partial covering of Au core with Pd significantly improved catalytic

activity of nanoreactors. Consequent catalytic runs revealed superior stability of AuPd@ZrO2

nanoreactors compared to the reference AuPd/ZrO2 catalyst. To the best of our knowledge this is the first

study of AuPd@ZrO2 nanoreactors. The authors would like to thank O. Callejas, M. Vega, E. Flores, F.

Ruiz, J. Peralta andM. Sainz for technical assistance. This research project was supported partly by

CONACyT (Mexico) and PAPIIT-UNAM (Mexico) through grants 179619 and 203813, respectively.

O-003

EFFECT OF GOLD CORE DECORATION WITH CERIA IN Au@ZrO2 NANOREACTOR AT THE REDUCTION OF 4-NITROPHENOL

Viridiana Evangelista1,a, Brenda Acosta1,b, Sergio Fuentes2,cand Andrey Simakov2,d

1 Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, B.C., 22860 (México).

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México (CNyN-UNAM), Ensenada, B.C., 22860 (México).

[email protected],[email protected],[email protected],[email protected]


13

Keywords: Gold, decoration, ceria, nanoreactors, nitrophenol reduction.

The catalytic reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride

is perhaps the most often used reaction to test the catalytic activity of metal nanoparticles in aqueous

solution at room temperature. The progress of the reaction can be easily monitored via UV–Vis

absorption spectroscopy. Nanoreactors of Yolk-Shell type refer to structures with a distinctive spherical

shell layer, generally formed by oxides, and a metal core inside as the active phase. Catalytic activity of

gold nanoparticles (cores) could be enhanced by the decoration of them with some materials due to

formation of highly active Au-oxide interface. The target of the present work was to decorate gold core

with ceria in Au@SiO2 and Au@ZrO2 yolk-shell nanoreactors was trough the formation of ceria species

in the void space of nanoreactors via homogeneous hydrolysis of the ceria precursor. The structure,

elemental distribution and core size distribution of yolk-shell nanoreactors were determined by STEM.

Porous structure of the prepared samples was evaluated using the BET method via N2 adsorption.

Electronic properties of gold cores were studied by UV-Vis spectroscopy. The decoration of gold cores

with ceria improved catalytic activity in the reduction of 4-Nitrophenol. In addition, it was found that

catalytic performance of Au-Ce@ZrO2 nanoreactor during 3 consecutive runs was increased. The latter

could be related with the some modification of nanoreactors due to partial reduction of ceria under

experimental conditions. The authors would like to thank E. Flores, F. Ruiz, J. Peralta, M. Sainzand O.

Callejas for their technical assistance. This research project was partly supported by CONACyT (Mexico)

and PAPIIT-UNAM (Mexico) through grants 179619 and 203813, respectively.

O-004

ONE-POT AMINATION OF MYRTENOL (TERPENE ALCOHOL) OVER AU AND Au-Pd SUPPORTED CATALYSTS

Yu.S. Demidova1,a, I.L. Simakova1,b, M. Estrada2,c, E.V. Suslov3,d, K.P. Volcho3,d, N.F.

Salakhutdinov3,d, V. Kriventsov1,e, D.Yu. Murzin4,f, S. Beloshapkin5,g and A. Simakov6,h

1 Boreskov Insitute of Catalysis, pr.Lavrentieva 5, 630090, Novosibirsk, Russia

2 Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, B.C., 22860, México.

3 Novosibirsk Institute of Organic Chemistry, 630090, Novosibirsk, pr. Lavrentieva 9, Russia.

4 Process Chemistry Centre, ÅboAkademi University, FI-20500, Turku/Åbo, Finland.

5 Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.

6 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México (CNyN-UNAM), Ensenada, BC, 22860, México.

[email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected].


14

Keywords: Amination, One-pot, gold catalysts, Myrtenol.

Terpene amines, synthesized from biorenewable materials, exhibit specific physiological

properties and can be used as intermediates of potential drugs. A perspective way of complicated amines

synthesisis the one-pot amination of alcohol in the presence of heterogeneous catalysts and consists of

three consecutive steps: i) the dehydrogenation of alcohol to aldehyde, ii) the condensation of aldehyde

with amine to form imine and iii) the hydrogen transfer to produce secondary amine. The present work is

aimed to the one-pot amination of myrtenol (natural terpene alcohol) over heterogeneous gold-based

catalysts. The gold (3wt. %) on different metal oxides were supported as a gold hydroxide by deposition-

precipitation method. Palladium (1wt. %) was deposited over selected samples, dried at room

temperature, by chemisorption from the agues solution of PdCl2. Before use all samples were pre-treated

in oxygen or in hydrogen flow at 350oC and characterized with XRD, TEM, XPS, EXAFS, FTIR and

MASS-UV-Vis in situ. The activity and selectivity of the catalysts in the myrtenol amination with aniline

were tested in the liquid-phase at 5-9 bar nitrogen pressure within 100-180oC temperature interval. The

increase of support acidity results in a relatively lower alcohol conversion which confirms initial alcohol

activation on the basic sites of metal oxide surfaces. On other hand, type of sample pretreatment affect

electronic state of gold changing relative contribution of metallic and cationic species or, in case of

bimetallic Pd-Au nanoparticles, the distribution of metals over nanoparticle. The highest activity among

the tested catalysts was obtained over pre-oxidized Au/ZrO2catalyst with both acidic and basic surface

sites. The data obtained are useful for the design of one-pot amination of alcohols with production of

various complicated amines to be used for the synthesis of drugs for neurological diseases. The authors

would like to thank O. Callejas, M. Vega, E. Flores, F. Ruiz, J. Peralta and M. Sainz for technical

assistance. This research project was supported partly by CONACyT (Mexico) and PAPIIT-UNAM

(Mexico) through grants 179619 and 203813, respectively.

O-005

TRANSFORMATION OF ORGANOSULFUR COMPOUNDS BY IMMOBILIZED BIOCATALYST IN IMPREGNATED SBA-15 MESOPOROUS MATERIALS

Karla Juárez-Moreno1,a, Yasmin Lozano Valenzuela2,b , Gabriel Alonso Núñez1,c, Sergio Fuentes1,d and Rafael Vazquez-Duhalt1,e

1 Centro de Nanociencias y Nanotecnologia, UNAM, Ensenada, BC, Mexico

2 Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California, Ensenada, BC, Mexico

[email protected], [email protected], [email protected], [email protected], [email protected]

Keywords: Enzyme-immobilization, biorefinery, desulfurization.


15

Immobilization of biomolecules on mesoporous materials has been successfully used for

biotechnological purposes, including several industrial applications. The enzyme immobilization on

nanostructured materials takes advantage of physicochemical properties from both biomolecules and

nanostructured supports. Herein we present the usage of SBA-15 silica and different metal-impregnated

preparations, SBA-15/Ti, SBA-15/CoMo and SBA-15/CoMoTi, as support materials for the physical

immobilization of the enzyme chloroperoxidase (CPO) from the black mold Caldariomyces fumago. The

enzyme load for each support and its specific activity on monochlorodimedone (MCD) and on

dibenzothiophene (DBT) were determined. Our results showed that immobilized CPO in SBA-15 silica

materials exhibit a higher stability in the presence of catalytic concentrations of H2O2 than free-CPO.

Although the total turnover (TTN) of free-CPO on MCD was higher than immobilized-CPO, SBA-

15/CoMo showed similar TTN value than the free enzyme. In addition, the capacity of immobilized CPO

to transform organosulfur compounds was tested. The biocatalytic transformation of several organosulfur

compound such as dibenzothiophene, 4,6-dimethyldibenzothiophene; benzyl sulfide; 1,2-

benzodiphenylene sulfide, thiophene and thianthrene were studied. Our results indicated that CPO

immobilized in SBA-15/Ti exhibit better specific activity with these compounds as compared to the other

enzymatic preparations. We can conclude that immobilization of CPO into SBA-15 materials provides a

favorable nano-environment and allows the enzyme to exhibit a higher stability than free preparation. We

suggest that impregnation of silica materials with Ti and CoMo enhances the oxidation of organosulfur

compounds mediated by CPO. The use of immobilized enzyme in mesoporous materials for the oil

biodesulfurization is discussed.

O-006

HOW TOXICARE COPPER OXIDE NANOPARTICLES? STUDYING OXIDATIVE STRESS IN SEA URCHIN EMBRYOS

Torres-Duarte Cristina1,a and Cherr Gary1,b

1 Bodega Marine Laboratory, University of California Davis. 2099 Westside Road, PO Box 247. Bodega Bay, CA 94923. United States.

[email protected], [email protected]

Keywords: Sea urchin embryos, copper oxide nanoparticles, oxidative stress.

Copper oxide nanoparticles (CuONPs) are one of the ten most produced engineered

nanomaterials. Their toxic properties make them useful as additives in pesticides and paints of boats

because they prevent the growth of organisms. These applications increase the likelihood of being

released to the soil and water, where they can also under go dissolution and induce oxidative stress

responses in non-target organisms leading to cell death, abnormal development and population declines.


16

We analyzed the effects of CuONPs exposure in sea urchin embryos, a well-known marine model

organism. After 96 h of development, we did not detect significant oxidative damage to proteins or lipids.

However, embryos exposed to 1 ppm CuONPs and greater developed abnormally and showed a decreased

total antioxidant capacity. At 5 ppm, 77% of embryos were abnormal and total antioxidant capacity was

70% of controls. In embryos exposed to 50 ppb of copper sulfate as a source of copper ions, the effects

were similar to the higher concentration of CuONP: no significant lipid or protein oxidation, 98%

abnormal development, and 84% of total antioxidant capacity in controls. Interestingly, the intracellular

copper concentration in the embryos exposed to 50 ppb copper sulfate and to 5 ppm CuONPs was 10 and

11 times higher than the concentration found in controls, respectively. Other studies have shown that at 10

ppm, ~1% of CuONPs dissolve. This suggests that at 5 ppm, CuONPs would undergo dissolution to an

equivalent concentration of ~50 ppb of copper ions. Thus, the toxic effects observed for CuONPs may in

part be due to the copper ions absorbed by the embryos. Although no effects were observed at

concentrations of CuONPs that are commonly observed in the environment, CuONPs can cause abnormal

development which may be linked to compromised antioxidant activity.

O-007

MOLECULAR DYNAMICS SIMULATIONS OF REVERSE MICELLAR SOLUTIONS WITH SOLVATION SALTS.

Rafael Navarro1,a, Victor R. Vasquez2,b, Olivia A. Graeve1,c

1 Department of Mechanical and Aerospace Engineering, University of California, San Diego 9500 Gilman Drive – MC 0411, La Jolla, CA 92093-0411, USA

2 Department of Chemical and Materials Engineering, University of Nevada, Reno1664 N. Virginia Street – MS 388, Reno, NV 89557, USA

[email protected],[email protected], [email protected]

Keywords: Molecular dynamics, reverse micelles, microemulsions, AOT, isooctane.

Reverse micellar systems consisting of water, AOT, and isooctane are studied using molecular

dynamics (MD) simulations. We have examined the distribution of micelle size as the ratio of water to

surfactant is varied as well as the addition of model salts. We will present the critical value of the ratio

that produces the two dynamical regimes that occur at low and high ratios of water to surfactant. At low

ratios, there is a significant deviation from sphericity and there exists oscillations of the structure. At high

ratios, the spherical radius increases with the ratio of water to surfactant. The positions of AOT molecules

relative to the center of the micelle have been tracked at high salt concentrations. High salt concentrations


17

lead to a decrease in micelle size due to a disruption in the solvation layer. The free energy of the system

has been measured with simulation time to ensure equilibrium of the system.

O-008

LIGHT SENSING DEVICES BASED ON ATOMICALLY THIN TMDCS

Néstor Perea-López1a, Ana Laura Elías1, Nihar Phradan2, Zhong Lin1, Bartolomeu Cruz-Viana1, Balicas Luis2, Humberto Terrones1 and Mauricio Terrones1,3c

1 Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA 16802, USA

2 National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA

3Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA & Research Center for Exotic Nanocarbons (JST), Shinshu University, Wakasato 4-17-1, Nagano 380-853, Japan


Keywords: Low dimensional systems, 2D Materials, TMDCs, Photocurrent, FET.

Few-layered films of different transition metal dichalcogenides (TMDCs) like MoS2, WS2, and

WSe2 were successfully used as light sensors. The film samples were structurally characterized by Raman

spectroscopy, atomic force microscopy, scanning electron microscopy, and high-resolution transmission

electron microscopy. The produced samples consisted of few layered sheets possessing up to 10 layers

obtained by different synthetic or isolation methods including low-pressure CVD, atmospheric-pressure

CVD and mechanical exfoliation. Current-voltage (I-V) and photo response measurements carried out at

room temperature were performed by connecting the TMDC layered sample with Au/Ti contacts. The

photocurrent measurements were carried out using five different laser lines ranging between 457 and 647

nm. The results indicate that the electrical response strongly depends on the photon energy from the

excitation lasers. In addition, it was found that the photocurrent varied non-linearly with the incident

power, and the generated photocurrent in the WS2 samples varied as a squared root of the incident power.

The device was tested for a long operation period at slow on and off illumination revealing good stability

of the photoswitching response. The response time of the devices was also measured and resulted in the

order of few microseconds, which is the fastest response reported so far for few layered transition metal

dichalcogenide devices. Because of its fast response, good responsivity and stability few-layered TMDCs

are strong candidates for constructing novel optoelectronic devices.

O-009

VIRUS-LIKE NANOPARTICLES AS POTENTIAL CARRIERS OF CYTOCHROME P450 FOR CHEMOTHERAPY PRO-DRUG ACTIVATION.


18

Lorena Sánchez-Sánchez1, Rubén D. Cadena2, Jaime Ruiz-Garcia3, Melissa S. T. Koay4, Jeroen J.M.T. Cornelissen4,Laura A. Palomares1 and Rafael Vazquez-Duhalt*1,

1 Institute of Biotechnology, Universidad Nacional Autónoma de México. Cuernavaca, Morelos.

2 Center for Nanosciences and Nanotechnology, Universidad Nacional Autónoma de México. Ensenada, Baja California.

3 Institute of Physics, Autonomous University of San Luis, San Luis Potosi, SLP, Mexico.

4 Department of Biomolecular Nanotechnology, MESA Institute of Nanotechnology, University of Twente, The Netherlands

[email protected]

Keywords: Bionanotechnology, CYP, Catalytic VPLs, Tamoxifen, Resveratrol.

This work shows for the first time, the encapsidation of a highly relevant protein in the

biomedical field into virus-like particles (VLPs). A bacterial CYP variant was effectively encapsidated in

VLPs constituted of coat protein from cowpea chlorotic mottle virus (CCMV). The catalytic VLPs are

able to transform the chemotherapeutic pro-drug, tamoxifen, and the emerging pro-drug resveratrol. The

chemical nature of the products was identified, confirming similar active products than those obtained

with human CYP. The enzymatic VLPs remain stable after the catalytic reaction. The aim and innovation

of this work is to make more efficient chemotherapy drugs activating them mainly in the target tissue

avoiding the dramatic side effects and reducing the doses.

O-010

THE ASSEMBLY PATHWAY OF AN ICOSAHEDRAL SINGLE-STRANDED RNA VIRUS

Rees F. Garmann

Department of Chemistry and Biochemistry, University of California, Los Angeles CA USA

[email protected]

Keywords: Self-assembly, RNA packaging, virus-like particle

The strength of attraction between capsid proteins (CPs) of Cowpea Chlorotic Mottle Virus

(CCMV) is controlled by the solution pH. Additionally, the strength of attraction between CP and the

single-stranded (ss) RNA viral genome is controlled by ionic strength. By exploiting these properties, we

are able to control and monitor the in vitro co-assembly of CCMV CP and ssRNA as a function of the

strength of CP-CP and CP-RNA attraction. Using the techniques of velocity sedimentation and electron

microscopy, we find that the successful assembly of nuclease-resistant virus-like particles (VLPs)

depends delicately on the strength of CP-CP attraction relative to CP-RNA attraction. If the attractions are

too weak, the capsid cannot form, if they are too strong, the assembly suffers from kinetic traps.


19

Separating the process into two steps – by first turning on CP-RNA attraction, and then turning on CP-CP

attraction – allows for the assembly of well-formed VLPs under a wide range of attraction strengths.

These observations establish a protocol for the efficient in vitro assembly of CCMV VLPs, and suggest

potential strategies that the virus may employ in-vivo.

O-011

CARBOXYMETHYLCELLULOSE COATED FE3O4 NANOPARTICLES FOR DRUG TRANSPORT AND DELIVERY

M.A. Mendez-Rojas1,a, G. Aguilera-Portillo1, C. Berry2, H. Patel3, O. Arias-Carrion4

1 Departamento de Ciencias Químico-Biológicas, Universidad de las Americas Puebla, Mexico;

2 Glasgow University, UK;

3 University of Waterloo, Canada;

4 Unidad de Trastornosdel Movimiento y Sueño, Hospital General Dr. Manuel Gea Gonzalez, México

[email protected]

Keywords: Magnetite, Nanoparticles, Nanomedicine, Dopamine.

Super-paramagnetic iron oxide nanoparticles (SPIONs) have attracted extensive interest due to

their superparamagnetic properties and their potential applications in medicine. In particular,

neurodegenerative diseases (e.g. Parkinson and Alzheimer disease) requiere innovative drug

transport/reléase systems. In this work we developed SPIONs coated with carboxymethylcellulose (CMC)

to evaluate their capacity for dopamine transport and drug delivery into the brain. SPIONs were

synthesized by chemical precipitation and further functionalized in their surface with CMC. Modified

nanoparticles were characterized by TEM, SEM, DRX, FTIR and DLS. Magnetic nanoparticles of 8-15

nm, monodistributed, highly stable and with good crystallinity were obtained. Confocal fluorescence

microscopy was used in order to determine nanoparticle internalization. Evaluation of dopamine loading

and releasing in vitro demonstrated long-term controlled drug delivery (up to 10 hours). In addition,

SPIONs had low toxicity on cell cultures (Le2 type cells) and diminished motor symptoms in a rat model

of Parkinson’s disease. Therefore, SPION@CMC systems are promising for direct drug delivery into the

brain for the treatment of neurological disorders.

O-012

DEVELOPMENT OF UNIQUE TRIBOLUMINESCENT COATINGS FOR STRUCTURAL HEALTH MONITORING APPLICATIONS

Ekaterina Novistkaya1,a, Manuel Herrera Zaldivar,2,b Gustavo Hirata Flores,2,c Olivia A. Graeve1,2,d


20


2 Centro de Nanociencia y Nanotecnología, Universidad NacionalAutónoma de México Apdo. Postal 14, CP 22800, Ensenada, B.C., México

[email protected],[email protected], [email protected]@ucsd.edu

Keywords: Triboluminescence, nanopowders, coatings, crack detection, combustion synthesis, structural

health monitoring.

We present a completely new paradigm for structural health monitoring based on materials that

emit a visible light signal as cracks propogating through it. This phenomenon is known as

triboluminescence and it allows one to identify and monitor active cracks in situ. Models systems of

luminescent Eu-doped Y2O3 (Y2O3:Eu) and Eu-doped BaAl2Si2O8(BAS:Eu) powders were prepared via

solution combustión synthesis using nitrates as precursors and carbohydrazide as a fuel. Morphology of

powders was analyzed by scanning electron microscopy (SEM), phase purity and crystallite size of

powders in the as-synthesized condition as well as after calcination were characterized by X-ray

diffraction (XRD). Particle size of the powders was analyzed by dynamic light scattering technique

(DLS). Additionally, photoluminescence (PL) and cathodoluminescence (CL) response of the powders

were measured. From the powders, luminescent paints were prepared by mixing the optimizedY2O3:Eu

and BAS:Eu powders in clear latex paint. SEM images of the paints were taken to determine the uniform

distribution of the powder inside the paint. Additionally, it was found that cracks were initiated in the

coating by the SEM electron beam. PL and CL spectra were measured for both types of paints, showing a

strong response. Measurements in SEM were completed to quantify the triboluminescence response of the

BAS paint. The technique for this measurement is unique and will be described in detail in this

presentation.

O-013

“EFFECT OF SILVER NANOPARTICLES IN CANDIDA ALBICANS”

Roberto Vazquez-Muñoz1,*, a, Ernestina Castro Longoria1,b, Miguel Avalos-Borja2,3,c

1 Departamento de Microbiología, CICESE, Ensenada, B.C. México

2 IPICT, División de Materiales Avanzados, San Luis Potosí, S.L.P. México

3 Centro de Nanociencias y Nanotecnología, UNAM, Ensenada, B.C.

[email protected], [email protected], [email protected].

Keywords: Candida albicans, silver nanoparticles, bionanotechnology, nanoantibiotics.


21

Silver nanoparticles (AgNPs) are among the most studied materials in the field of

bionanomedicine, due to the microbicidal properties of silver. AgNPs could be more biocompatible than

colloidal silver, preserving or enhancing its microbicidal action. Infectious diseases are a major problem

worldwide. Fungal infections are the fourth leading cause of death, where candidiasis is the most

common. This disease is generated by Candida spp, with Candida albicans as the most common. The use

of antibiotics is not enough to combat infectious diseases, so alternative treatments are studied, such as

nanotechnology. In this study we evaluate the effect of AgNPs against C. albicans, due to its clinical

importance.The inhibitory concentrations (MIC and IC50) of AgNPs were determined by the modified

micro dilutions test M27-A2 of the CLSI, using the reference strain C. albicans ATCC SC5314. To

determine the intracellular distribution of AgNPs, fungal cells (2.5 x 106/ml) exposed to the MIC were

fixed with 2% glutaraldehyde in phosphate buffer and post fixed with 1% OsO4. After fixation, cells were

dehydrated and embedded in Spurr’s resin to finally obtain ultrathin sections. Samples were examined

under TEM without post-dying. Results show antifungal activity at lower concentrations than those of

fluconazole. Currently, the mechanism of action of AgNPs is poorly understood. It was found that

AgNPs, accumulate outside the cell but also smaller NPs localize throughout the cytoplasm. Energy

dispersive spectroscopy (EDS) and crystallography analysis confirms the presence of crystalline silver

inside the cells. From the results obtained it is assumed that AgNPs used for this study do not penetrate

the cell, but possibly free silver ions infiltrate into the cell and AgNPs are formed by reduction with

soluble proteins present in the cytoplasm as no relationship was found with cell membrane or any

membranous organelle.

O-014

MORDENITE-BASED NANOSTRUCTURED COMPOSITES: CONTROLLED SYNTHESIS AND APPLICATIONS

O. E. Jaime-Acuña1,a, H. Villavicencio2, V. Petranovskii3, R. Vázquez-González4, Huerta-Saquero3, S. Águila3, R. Vázquez-Duhalt3, and O. Raymond3,b

1 Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación superior

de Ensenada-Centro de Nanociencias y Nanotecnología- Universidad Nacional Autónoma de México, Ensenada 22890, Baja California México.

2 Dirección Nacional de Informática Educativa, Ministerio de Educación de Cuba, La Habana, Cuba.

3 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, AP 14, Ensenada 22890, Baja California México.

4 Departamento de Geofísica de Exploración, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, México.


22


Keywords: Synthesis, composites, active nanostructures, photoactivity, optic-spectral properties,

biological applications.

The synthesis of porous materials is important for the chemical industry because of the various

potential uses that they may have. Furthermore, the inclusion of transition metals and/or semiconductors

nanoparticles in these matrices change their properties (optic-spectral and structural) allowing the design

and development of new materials oriented to specific final applications. Different Si and Al precursors

(including waste solid materials derived from geothermal energy conversion process) were used in this

work following the MX/a/2012/013218 patent route to synthesize metal/mordenite,

semiconductor/mordenite, and metal/semiconductor/mordenite composites, demonstrating the capability

to governing the morphology and chemical composition of the obtained materials. Variations of

morphology and chemical composition of synthesized nanostructured mordenite-based composites were

characterized using XRD, HRTEM, SEM, EDS, ED, UV-Vis spectroscopic, infrared and

photoluminescence techniques. Some applications such as photocatalysts, bacterial growth inhibitors and

enzyme supports are being tested and discussed. This work was partially supported by CONACYT

(Grants 127633 and 102907) and DGAPA-UNAM (Grants IN113312 and IN110713). The authors thank

E. Aparicio, I. Gradilla, and F. Ruiz for their technical assistance.

O-015

PINUS CONE MICROFIBER AS POLYSTYRENE REINFORCEMENT

García Méndez R. F.1, 2, a, G. Alonso-Núñez3, b,Y. Gochi-Ponce1, c.

1 Instituto Tecnológico de Oaxaca, Department of Chemical and Biochemical Engineering, Av. Ing. Víctor Bravo Ahuja 125 esquina Calzada Tecnológico, Oaxaca C. P. 68030, México

2 Instituto Tecnológico Superior de Teposcolula, Paraje el Alarcón San Pedro y San Pablo Teposcolula, Oaxaca, C. P. 69500, México

3 Universidad Nacional Autónoma de México, Center for Nanoscience and Nanotechnology, Km 107 Carretera Tijuana-Ensenada, Ensenada, B.C., C.P. 22860, México


Keywords: Polystyrene, microfibers, compounds, mechanical properties.

The present work shows the results of the mechanical properties of a polymeric compound made

from polystyrene and Pinus pseudostrobus var oaxacana cone microfibers. Actually, the Pinus conesare

only one part of the biodiversity in the Mixteca region in Oaxaca State of Mexico. In some cases, pine

cone fibers are mainly used as biosorbent for metal and dye waste waters. Also, some works have shown

that the fibrillar morphology and the good mechanical properties of this plant allow their use as filler in


23

the material. The use of these materials in the development polymeric compound is an alternative for

specific applications. However, it is necessary to determine their mechanical properties before to apply

the resultant material. Herein the experimental procedure began with microfibers of an approximate size

of 850 µm, and then the compounds from two concentrations were prepared: 10 and 20(wt.%), and 0

(wt.%) as reference sample. Based on the standard ASTM D-638 stress tests were carried out, we use a

strain of 5 mm/min. Statistical analysis were performed for each mechanical property at a significance

level of 5%. The results showed that the addition of cone microfiber has a significant effect in the

composite material. The higher concentration is proportional to the ultimate tensile stress and modulus of

elasticity, and increases 16.59 MPa and 42.10 MPa, respectively. However, the tenacity as energy

indicator showed that the composite material could absorbs before to fracture, it decreases at 0.54 J. The

strain statistically is not affect when the values are between 0.24 mm/mm and 0.20 mm/mm. Finally,

according to the stress-strain diagram, the addition of cone microfibers becomes harder, tough and elastic

linearly before to fracture the polymer compound. These results can be compared with the reference

sample.

O-016

OPTICAL SPECTRA OF GOLD NANOPARTICLES SUPPORTED ON ZEOLITES IN THE PRESENCE OF VARIOUS CATIONS (NA, CU, NI, FE)

Catalina López Bastidas1,a, Elena Smolentseva1,b, Roberto Machorro1,c and Vitalii Petranovskii1,d

1 CNyN, UNAM Ensenada, México

[email protected], [email protected], [email protected], d [email protected]

Keywords: Gold nanoparticles, zeolites, optical spectra.

The optical spectra of supported gold nanoparticles is of interest in both theoretical and practical

cases. In the first case the information obtained from the spectra leads to better understanding of the

influence of the environment on the fundamental collective electronic states available to electrons that

form the nanoparticle as well as the dynamic screening properties of the substrate and the effects

identifiable optically. This understanding can then be applied to the development of optical tools to

monitor and eventually regulate the nanostructured material synthesis. In this work we present the

experimental and theoretical analysis of optical spectra of gold nanoparticles supported on zeolite

templates which have been pre-loaded with metallic nanoparticles of different species. The permanence of

the precursor after thermal treatment is discussed as well as the resulting reflectance spectra.

O-017

PREDICTING THE PHYSICAL PROPERTIES OF TEXTURED POLYCRYSTALS


24

Luis E. Fuentes-Cobas1,a, Alejandro Muñoz-Romero2,b, María E. Montero-Cabrera1,c, Luis Fuentes-Montero3,d and María E. Fuentes-Montero 4,e

1 Centro de Investigación en Materiales Avanzados, Chihuahua, Mexico

2 Delphi Automotive Systems, The Mexico Technical Center, Ciudad Juarez, Mexico

3 Diamond Light Source Ltd., Oxfordshire, UK

4 Universidad Autónoma de Chihuahua, Chihuahua, Mexico

[email protected],[email protected],[email protected],[email protected], [email protected]

Keywords: Texture, properties prediction, magnetoelectricity, piezoelectricity

A system of methods and programs for the prediction of physical properties in polycrystals are

presented. "Principal" properties, which relates actions and responses within the same subsystem (electric,

elastic, ...), as well as “coupling” properties (e.g. piezoelectricity), linking actions and responses

associated with various subsystems (electro-elastic, magneto-electric ...) are analyzed. Tensor ranks from

1 to 4, with polar and axial characteristics, are considered. Virtual-time inversion (the case of

magnetoelectricity) is taken into account. For both matrix and surface representations, selection rules

derived from crystal and texture symmetries are applied. To predict the effective values of coupling

properties, precautions required for application of the Voigt, Reuss and Hill approximations are pointed

out. At all stages of the proposed methodology, a symmetrized spherical harmonics treatment of the

orientation distribution functions, inverse pole figures and (single and polycrystals) physical properties is

applied. The established mathematical model has been systematized as a functional program. For the

proposed application, the input data are the single-crystal tensor components, the polycrystal texture and

the sample stereography. Discussion of piezoelectricity in a ferro-piezoelectric ceramic with a typical

texture illustrates the application of the suggested methodology. Coupling properties predicted by the

suggested route are satisfactorily close to experimentally measured ones.

O-018

ADVANCES IN MULTIFERROIC MATERIALS

Jesús M. Siqueiros1,a, Oscar Raymond1,b, Ma. De la Paz Cruz1,c, Alejandro Durán1,d, Jesús Heiras1,e, José Juan Gervacio1,f, Mario Curiel2,g, Jorge Portelles3h, Reynaldo Font3,i, Juan Fuentes3,j, Nelson Suárez3,k, Dolores Durruthy4,l, Carlos Ostos5,m, Lourdes Mestres6,n, Darío Bueno-Baqués7,o, Duilio Valdespino8,p, Mayra Ramírez9,q Espiridión Martínez9,r

1Centro de Nanociencias y Nanotecnología, UNAM, Carretera Tijuana-Ensenada, Ensenada, B. C., MÉXICO, 22860.

2Instituto de Ingeniería, UABC, Mexicali, Baja California, México 21280

3Facultad de Física, Universidad de La Habana, San Lázaro y L, La Habana, 10400, CUBA.


25

4Departamento de Física Aplicada, ICIMAF, CITMA, 15 # 551, Vedado, La Habana, CP 10400, Cuba.

5Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, COLOMBIA.

6Facultat de Química, Universitat de Barcelona, Av. Diagonal 648, 08028, Barcelona, ESPAÑA.

7Centro de Investigación en Química Aplicada, Saltillo 25253, Coahuila, México

8Posgrado en Ciencia e Ingeniería de Materiales, UNAM

9Posgrado en Física de Materiales, CICESE-UNAM, MÉXICO

[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected],

[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected],


Keywords: Multiferroics, magnetoelectrics, ferroelectrics, photovoltaic effect.

Multiferroics are materials where at least two of the four known forms or ferroicity, that is,

ferroelectricity, magnetism, ferroelasticity and ferrotoroidicity coexist. Materials that possess one of those

properties have been extensively studied but those that show more than one are scarce and there is only a

handful where coupling between those two properties is measurable. Responsible for such situation are d

electrons in transition metals that are essential for magnetism but hinder or prevent off-center distortion

and, consequently, ferroelectricity. To design and fabricate multiferroic ceramics and thin films, several

methods have been tried. For instance, the existence of two available sites for substitution in the

(perovskite) structure allows for one ion to be the ferroelectric source (A-site) and the other (B-site) the

magnetic source. Another approach would be a biphasic multiferroic material constituted of a solid

solution of a ferroelectric and a magnetic material. An example could be a nanostructured compound

combining the properties of BaTiO3, a ferroelectric material and CoFe2O4 a magnetic material. Still

another possibility would be the case where the ferroelectric behavior results from redistribution of charge

density of the cell produced by a magnetic transition (type II multiferroic) as seems to occur in

TbMnO3.Representative examples of these three distinctive routes for obtaining mutiferroicity are given

in this presentation. Experimental results on materials such as Pb(Fe0.5Nb0.5)O3 (PFN), BiFeO3 (BFO),

BaTiO3-CoFe2O4, YCrO3 (YCO) and TbMnO3 (TMO) as ceramics or thin films are used to illustrate how

those different approaches render multiferroic behavior. This line of investigation plus the work being

done on lead free materials and bulk photoelectric effect in non-centro-symmetric materials sum up very

well the research being done in our group. Support from CoNaCyT (Grants 166286, 127633, 174391 and

101020) and DGAPA-UNAM (Grants IN106414, IN113312, IN107312,IN103213) is acknowledged. The


26

authors thank E. Aparicio, F. Ruiz, I. Gradilla, F. Escobedo, P. Casillas, J. A. Díaz, D. Domínguez, and E.

Sámano for their technical assistance.

O-019

TUNNELING BETWEEN WEIRD ELECTRODES THROUGH BIZARRE BARRIERS.

Gabriel D. Ramos R.1a and Jesús Heiras2b

1 Posgrado en Ciencia e Ingeniería de Materiales, CNyN, UNAM, México

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México Km 107 Carr. Tij-EnsCol. Pedregal Playitas Ensenada B. C. cp 22860México


Keywords: Magnetic tunnel junctions, measurement of tunneling characteristics, nonlinear devices

A tunnel junction is formed when an ultrathin insulating film is sandwiched between two metallic

electrodes. If metals and insulators belong to the same structural family, fully epitaxial junctions may be

realized. In principle, both barrier thickness and barrier/electrode interfaces can be controlled at the unit-

cell level. When ferromagnetic metals are used as electrodes, their non-equivalent DOS for spin-up and

spin-down states bring about novel physical effects. The total tunnel current is the sum of the currents for

spin-up and spin-down. Then, the conductance of a magnetic tunnel junction (MTJ, two ferromagnetic

electrodes sandwich a dielectric tunnel barrier) in the parallel (P) and antiparallel (AP) configurations of

the electrodes magnetization, is simply proportional to the product of the DOS of the electrodes. Materials

with a 100% spin polarization are called half-metals: they are metallic for one spin direction and

insulating for the other. At the Fermi level, their DOS is finite for one spin direction and zero (or

vanishingly small) for the other. Junctions with half-metallic electrodes and ferroelectric barrier will be

built to take advantage of the four possible states combining the electrodes’ spin polarization and the

electric polarization of the barrier, leading to a tunnel electromagnetoresistance (TEMR) effect. To extract

the valuable information included in tunneling, it is necessary to measure derivatives of the tunneling

current, tunneling characteristics, with high resolution. A conductance bridge has been designed and it is

combined with a modulation technique to provide adequate resolution, reasonable precision and high

stability. The goal is to amplify the nonlinear deviations and subtle features of I vs. V and its derivatives.

We are implementing a complete set up to obtain high quality measurements of the derivatives of I vs. V,

taking advantage of the amazing power of a Lock-In amplifier and the conceptual beauty of our

conductance bridge.

O-020

INSULATING AND PLUGGING-IN ELECTRONIC NANO-DEVICES.


27

J.M. Romo-Herrera1a, D. Domínguez1b, M. Cardoza1c@, J.R. Rodríguez1d@,G. Alonso-Nuñez1e, F. Muñoz-Muñoz1f, H. Tiznado1g and O.E. Contreras1h

1 CNyN-UNAM, Ensenada B.C., México.

@ Posgrado en Física de Materiales CNyN-UNAM / CICESE.


x,[email protected],[email protected],[email protected], [email protected]

Keywords: nanotubes, atomic layer deposition, devices, nano-electronics.

The tendency to produce faster electronic products, has led to increase the device density

(miniaturization) of integrated circuits (IC). The conventional manufacturing methods are reaching their

limits. Thus, innovative fabrication routes are being pursued. In this context, the synthesis and electronic

properties evaluation of nano-devices are needed. Here we present some of our recent results on this

electronics devices line. This includes electrical insulation of Carbon Nanotubes (CNTs) and the

plugging-in of semiconductor devices into the macro-world. It is shown how atomic layer deposition

(ALD) allows to coat nanotubes with an insulator (Al2O3) shell. This can be achieved in large quantities

(tens of mg per batch) for electrical wiring purposes. The high resolution transmission electron

microscopy (TEM), together with the energy dispersive X-ray spectroscopy (EDXS) analysis allowed to

establish an abrupt interface between the insulating coating and the conductor CNT wire. Additionally,

the advances in pugging-in electronic devices into electrical contacts are presented. This is achieved by a

photo-lithography process to grow the millimeter-contacts, followed by in-situ manipulation in the

electron microscope of the device, to end up with the Focus Ion Beam assisted deposition of the micro-

contacts.Acknowledgements: We thank E. Aparicio, A. Tiznado, I. Gradilla F. Ruiz, J. Díaz and Eric

Flores for technical assistance; and projects DGAPA-PAPIIT IN-109612, IN114209-3 and IN104714 and

CONACyT 82984, 83275 and 174689 for financial support.

O-021

PURELY ELECTRONIC THIRD ORDER NONLINEAR RESPONSE OF CONCAVE CUBE GOLD NANOPARTICLES

Héctor Sánchez1,a, Raúl Rangel1,b

1 CICESE, Carretera Ensenada-Tijuana No.3918, Zona Playitas, C.P. 22860, Ensenada, B.C., México

2 CNyN, Km. 107 Carretera Tijuana-Ensenada, AP 14, CP 22800, Ensenada, B.C., México

[email protected], [email protected].

Keywords: Nonlinear response, Optical Kerr Effect, Zscan technique, Ultrashort pulses.


28

Gold nanoparticles have drawn interest in recent years due to their potential for applications in

the fields of photonics and biomedical uses. Due to this, effort has been done to develop specialized

symmetries that enhance certain optical properties of the nanoparticle. It has been found that the presence

of sharp edges and tips in a nanoparticle in dielectric medium provide a large enhancement of the electric

field around it. It also has been found that the size, shape and composition of the nanoparticles determine

the third order susceptibility χ^((3) ) of the medium. We present the study of purely electronic χ^((3) ) of

concave cube Au nanoparticles diluted in distilled water. Nanoparticles of 10nm, 50nm and 100nm side

length were studied, as well as the seeds. The real and imaginary parts of the third order susceptibility

χ^((3) ) were resolved using the Z-scan technique with 83 fs pulses in the near IR at a 94MHz repetition

rate and 200mW average optical power. In order to discriminate against the optical thermal response, a

pulse train chopper was utilized and as such, the purely electronic response was isolated for nanoparticles

of 100nm side length. The purely electronic nonlinear refractive index n_2 related to the Iχ^((3) ) was

obtained for chopping frequencies up to 600 Hz and found to be n_2=3.82×〖10〗^(-17) m^2⁄W. The

nonlinear absorption contribution β related to the real part of Rχ^((3) ) was found to be negligible for

all the samples under the experiment’s conditions.

O-022

GROWTH AND CHARACTERIZATION OF Mn DOPED SnO2 NANOWORES, NANOBELTS, AND MICROPLATES

M. Herrera1,a, D. Maestre2,b, A. Cremades2,c and J. Piqueras2,d

1 Centro de Nanociencia y Nanotecnología, Universidad Nacional Autónoma de México Apdo. Postal 14, CP 22800, Ensenada, B.C., México

2 Departamento de Física de Materiales, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid 28040, Spain

[email protected],[email protected],[email protected], [email protected]

Keywords: Tin oxide, nanostructures, point defects.

Undoped and Mn doped SnO2 nanowires, nanobelts, and microplates have been grown by a

thermal evaporation method that enables the morphology and the Mn content in the structures to be

controlled. The structural and morphological characterization was carried out by scanning and

transmission electron microscopy (SEM and TEM) and electron back scattered diffraction (EBSD). A

crystallographic model has been proposed to describe the SnO2:Mn microplates. X-ray photo electron

spectroscopy (XPS) and energy dispersive spectroscopy (EDS) demonstrated the incorporation of Mn into

the SnO2 lattice in concentrations up to 1.6% depending on the thermal treatment employed for the


29

growth of the structures. Variations in the luminescence of the doped nanostructures as a function of the

Mn content have been studied. A correlation between facets of the SnO2:Mn microplates, identified by

EBSD, with higher Mn content, and the increase of the luminescence emissions associated to oxygen

vacancies related defects was demonstrated.

O-023

ULTRASOUND POWERED NANOMOTORS FOR BIOMEDICAL APPLICATIONS

Victor Garcia-Gradilla1,2,a, Jahir Orozco1, Sirilak Sattayasamitsathit1, Fernando Soto1, Filiz Kuralay1, Ashley Pourazary1, Adlai Katzenberg1, Wei Gao1, Yufeng Shen1, Joseph Wang1,b

1 Department of Nanoengineering, University of California, San Diego, La Jolla, California 92093, USA.

2 Universidad Nacional Autónoma de México CNyN. Km 107 Carr. Tij.-Ens. Ensenada, B.C. Mexico.


Keywords: Nanomotors, biomedical, ultrasound.

Nanomotors is an emerging research area due to de potential applications at micro and nano scale

like transport of nano targets, bioisolation, nano surgery, directed drug delivery, nano fabrication, etc.

Different designs and propulsion mechanisms have been developed to drive these featured nanomachines.

One of the most developed ones are the fuel based nanomotors, but these category of nanomachines are

limited by the viability of the fuel requirement in the working media. To overcome this limitation,

different efforts have been made to develop alternative strategies to propel nanomotors like magnetic,

light and ultrasound propelled nanomotors. In this work it is presented ultrasound powered nanomotors

fabricated by template chemical electrodeposition. Advanced capabilities are incorporated to these

nanodevices like magnetic guidance, motion in different untreated media, cargo towing, isolation of

biological targets and drug delivery. The featured capabilities in addition to the fabrication method, low

deleterious effects and the widely use of ultrasound in medicine make this nanomachine highly promising

tool for in-vivo biomedical applications. This project received support from the DTRA-Joint Science and

Technology Office for Chemical and Biological Defense (Grant no. HDTRA1-13-1-0002). V.G. is

acknowledges financial support from CNyN-UNAM and DGAPA-UNAM fellowship (Mexico).

O-024

BULK IRON-BASED AMORPHOUS ALLOYS AND COMPOSITES WITH ENHANCED DENSITY

James P. Kelly1,2,a, Hoorshad Fathi-Kelly1,2,b, Linda E. Jones2,c, Olivia A. Graeve1,2,c

1 Department of Mechanical and Aerospace Engineering, University of California, San Diego


30

9500 Gilman Drive – MC 0411, La Jolla, CA 92093-0411, USA

2 Kazuo Inamori School of Engineering, Alfred University, Pine Street, Alfred, NY 14802

[email protected], [email protected],[email protected],[email protected]

Keywords: Spark plasma sintering technique.

We recently developed a methodology for consolidating structurally amorphous metal powders

and composites using SAM2x5 as a base system. The high critical cooling rate of this alloy prevents

obtaining thick parts by quenching techniques. We use a combination of powder metallurgy and

fundamentals of glass science to obtain thick samples, up to 6 mm. Amorphous metal powders were

consolidated using the spark plasma sintering (SPS) technique. A time-temperature-transformation (TTT)

diagram was developed to establish critical SPS processing parameters. SAM2x5-tungsten composites

were prepared by using various tungsten particle sizes. Increased tungsten content could be added as the

particle size was increased. We were able to increase the density of the base system by 34%. Current

strategies for continuing to increase the density are discussed, by increasing the tungsten content of the

matrix and dispersed phases by tungsten additions and thermodynamic modeling of a new alloy

composition for the matrix. The modeling requires a quantitative determination of the strain and the

liquid us temperature of a given composition to determine the eutectic depth. The determination of the

alloy eutectic depth requires equilibrium calculations to determine the stable phases as a function of

temperature. An optimum matrix composition will have as high of tungsten content as possible, while

still maintaining sufficient strain and depth of eutectic to have adequate glass forming ability. We expect

to be able to produce samples with density at least 50% higher than the base system using this approach.

O-025

SUPER-RESOLUTION IN TIME.

Mufei Xiao1,a and Jingsong Wei2

1 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, km. 107 Carretera Tijuana-Ensenada, Ensenada, Baja California CP 22860, México

2 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China

[email protected]

Keywords: Super-resolution; diffraction in time; Moshinsky function.

On-going work is reported about a novel idea to realize super-resolution in time domain. Optical

resolution is limited by the diffraction. The smallest object one can see with an optical microscope is

about a half of the light wavelength. Various proposals have been so far reported to overcome this


31

fundamental limit, such as the near field microscopy. We herewith put forward a novel idea to overcome

the diffraction limit. The idea is to realize a reduction of the diffraction in time. We previously published

a number of papers about the transient propagation of electromagnetic waves. The work is similar to the

atomic shutter problem addressed a long time ago by Mushinsy, and the solution involves a Mushinsky

function. It was found that the transient propagation behaviors quite different from the stationery

propagation, and there appears a diffraction in time. Therefore, there seems a chance to reduce the

diffraction in the time domain. We start with a thin metallic film as a model for the concept of transient

light, and relevant experimental efforts are being carried out.

O-026

MEASUREMENT OF DIFFUSION COEFFICIENTS ON FLUID SURFACES.

Obed Lugo1,a and Amir Maldonado,2,b

1 Posgrado en Ciencia de Materiales, Universidad de Sonora, 83000 Hermosillo, Sonora, México

2 Departamento de Física, Universidad de Sonora, 83000 Hermosillo, Sonora, México


Keywords: Fluid surfaces, diffusion, fluorescence recovery after photobleaching.

Fluid surfaces are ubiquitous in materials science. Some examples are: the free surfaces of liquids

or liquid droplets; the interface between aqueous and oil domains in emulsions and microemulsions; the

layers of smectic liquid crystals; and the membranes of lyotropic liquid crystals. These systems have

applications in electronics, pharmaceutics, cosmetics, nanoparticle synthesis, etc. Among the physical

properties of the fluid surfaces, its fluidity is important since it controls the rate of self-assembly of

molecules. For this reason, the diffusion coefficient of molecules on the surfaces is a relevant parameter

of these systems. In this work we describe the design and construction of an experimental set up built for

the measurement of diffusion coefficients of molecules confined in or between fluid surfaces. The set up

uses the fluorescence recovery after photobleaching method, where a high power laser beam (488 nm)

bleaches the fluorescence in a region of the sample, in order to follow the recovery of fluorescence. We

illustrate the use of the technique with an investigation of the diffusion coefficient of both amphiphilic

and water-soluble molecules in the membranes of lyotropic sponge phases.

O-027

PRODUCTION OF Ag NANOPARTICLES BY FLUIDIZED-BED ASSISTED WITH ATMOSPHERIC PRESSURE PLASMA.

E. Pahuamba1a, H. Tiznado1b,G. Soto1c, J. Romo-Herrera1d, D. Domínguez1e, O. Contreras1f.


32

1 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada, C.P 22860, Ensenada B.C. México

[email protected];[email protected],[email protected],[email protected],[email protected],[email protected]

Keywords: Silver nanoparticles; Plasma-Fluidized-bed.

It is presented the synthesis of silver nanoparticles through a short duty method: fluidized-bed

combined with plasma as the activation energy. Silver nanoparticles were obtained from AgNO3 after a

few minutes processing time, as revealed by TEM images, where an average diameter of 5 nm is

observed. Conventional resolution XPS showed that most of the silver chemical state is metallic, while

CO-Infrared exposed some contribution from silver oxide species, which is later confirmed through high

resolution XPS analysis. The main characteristics of this method are the capability to operate at

atmospheric pressure and the commercial availability of the plasma source (Multiplaz.com). These factors

make this technique very attractive for mass production of nanoparticles. This work was supported by

DGAPA-UNAM IN114209-3and CONACyT 83275 projects.

1st POSTER SESSION

P-001

DECOMPOSITION OF LOW DENSITY POLYETHYLENE TO CARBON FOR CATALYTIC

OXIDATIVE PYROLYSIS

Villalón López U.A1, a, Quintana Melgoza J.M.1, b and Ávalos Borja M.2, 3, c

1 Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad, 14418, Parque Industrial Internacional Tijuana, Tijuana B.C. 22390.

2 Centro de Nanociencias y Nanotecnología, UNAM, Apdo. Postal 2681, C.P. 22800. Ensenada, B.C., México.

3 On leave at Instituto Potosino de Investigación Científica y Tecnológica, División de Materiales Avanzados. Camino a la Presa de San José #2055, Lomas 4ta sección, C.P. 78216, San Luis Potosí, S.L.P., México.

[email protected], [email protected], c [email protected]

Keywords: LDPE, Pyrolysis, Carbon, Catalysis, MSW, XRD, SEM, EDS. NiO, γ-Al2O3.


33

Low density polyethylene (LDPE) is a major solid waste that accumulates 19 million ton/year on

the planet being, therefore, a big environmental problem worldwide (in Mexico we produce 480 thousand

ton/year). The aim of this work is to decompose LDPE into more environmentally friendly compounds.

The system used for this purpose uses NiO/γ-Al2O3 (5% NiO) as catalyst, in airflow at 400 °C for 1 h.

Characterization of this material was done by X-ray diffraction (XRD), energy dispersive spectroscopy

(EDS) and scanning electron microscopy (SEM). After catalytic oxidative pyrolysis process, the

decomposed LDPE generates gaseous products (17%) and solid hydrocarbons (68%). However, in our

case, a fraction of the product is obtained in the form of carbon (15% of the initial LDPE) that can be used

as precursor for the formation of useful allotropes. The authors thank CONACYT for a scholarship to

UAVL, and financial support through grant CB-2010-01-151551. We are very grateful to A.I. Peña

Maldonado and B.A. Rivera Escoto, for technical assistance. We also thank MyDCI-FCQI-UABC and

LINAN-IPICyT, for providing laboratory support.

P-002

SYNTHESIS, CHARACTERIZATION AND TOXICOLOGICAL IN-VITRO ACTIVITY OF

NANOCAPSULES CONTAINING ACTIVE INGREDIENTS OF MEDICINAL PLANTS

E.Sánchez1a, F. Mercado1b, J. Soriano1,L. Flores1, R. Vazquez1, A. Alvarado1, M. Domínguez1, C. Espinoza1, M.A. Mendez2, L. Hernández2, R. Cachau3, Z. Juárez1, M. Miranda1, T.D. Palacios-Hernández1,2c1

1 Ciencias Biológicas, UPAEP, Mexico.

2 Ciencias Químico-Biológicas, UDLAP, Mexico.

3 Frederick National Laboratory for Cancer Research, Frederick MA, USA.


Keywords: Nanocapsules, plant extracts, antimicrobial agents.

The synthesis, characterization and antimicrobial activity of calcium alginate nanocapsules

containing active ingredients of Matricaria chamomilla and Catharanthus roseus, is reported. Plants were

collected from Atlixco, Puebla, Mexico, and stem, flowers, leaves and roots were employed to obtain

hexane, chloroform and methanol extracts of both plants. The extracts obtained were dissolved in glycerol

and/or water. Synthesis of calcium alginate nanocapsules was developed by micro emulsion method. The

nanocapsules obtained were characterized by Low Voltage Electron Microscopy (LVEM) at 45 kV,

Dynamic Light Scattering (DLS) and DRIZZLE method. Antimicrobial activity of extracts and

nanocapsules was evaluated employing antibiograms, upon S. aureus and E. coli. Results obtained by


34

LVEM showed that nanocapsules size range was between 35-100 nm, with morphology previously

reported for soft spheres (1). DLS demonstrated a hydrodynamic ratio between 13-100 nm, and large

aggregation of 1 µm. DRIZZLE analysis showed that aggregates were confirmed by nanocapsules in a

size range of 50-100 nm. Antimicrobial activity showed that nanocapsules containing chloroformic

extracts of flower and leaves in M. chamomilla, and nanocapsules containing hexane extracts of C. roseus

inhibited bacterial growth.

P-003

UC CENTER FOR ENVIRONMENTAL IMPLICATIONS OF NANOTECHNOLOGY.

Andre E. Nel1,a, Arturo A. Keller2, Hilary Godwin1, Yoram Cohen1, Patricia Holden2

1 University of California Los Angeles, Los Angeles, CA, 90095, United States.

2 University of California Santa Barbara, Santa Barbara, CA, 93106, United States.

[email protected]

Keywords: Risk assessment, environmental implications, nanotoxicology.

The University of California Center for Environmental Implications of Nanotechnology (UC

CEIN) was established in September 2008 with a long-term vision of developing a multidisciplinary and

quantitative framework for assessing the potential environmental impact, hazard and exposure to ENMs,

in both their primary as well as commercial nano-enabled formulations. The Center also provides

feedback and guidance for the safer implementation of nanotechnology, including risk reduction and safer

design strategies. The multidisciplinary approach of the Center involves materials science, environmental

chemistry and engineering, toxicology, ecology, social science, computer science and modeling, statistics,

public health, law and policy formulation. The research of the UC CEIN is carried out by 33 distinct but

interactive research projects across seven interdisciplinary research themes:

Theme 1: Compositional and Combinatorial ENM Libraries for Property-Activity Analysis

Theme 2: Molecular, Cellular, and Organism High-Throughput Screening for Hazard Assessment

Theme 3: Fate, Transport, Exposure, and Life Cycle Assessment

Theme 4: Terrestrial Ecosystems Impact and Hazard Assessment

Theme 5: Marine and Freshwater Ecosystems Impact and Toxicology

Theme 6: Environmental Decision Analysis for ENMs

Theme 7: Using CEIN Knowledge Generation to Engage and Impact Multiple Stakeholders


35

Collectively, these themes address the complexity of the ENM physicochemical properties

involved in hazard generation, establishment of structure-activity relationships (SARs), and use of

exposure assessment to evaluate ecosystems impact. The UC CEIN’s vision is to generate predictive tools

for environmental hazard and exposure assessment as well as to develop strategies to ensure the safe

implementation of nanotechnology to the benefit of society, the environment and the economy. These

tools and knowledge are disseminated through vibrant and impactful educational and outreach programs.

Through the pursuit of interdisciplinary, predictive and high throughput approaches, the UC CEIN has

made, and will continue to make, a transformative impact on nanotechnology environmental health and

safety assessment.

P-004

NO REDUCTION BY CO OVER NiO, CuO AND ZnO CATALYST

Flores-Sánchez L.A.1,a, Quintana-Melgoza J.M.1,b, Gómez-Cortés A.2,c, Díaz G.2,d and Ávalos-Borja M. 3,4,e

1 Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad, 14418, Parque Industrial Internacional Tijuana, Tijuana B.C. 22390, Mexico.

2 Instituto de Física, Universidad Nacional Autónoma de México (UNAM), Circuito de la Investigación Científica S/N, A. P. 20-364, C. P. 01000, México D.F., Mexico.

3 Centro de Nanociencias y Nanotecnología-UNAM, A. P. 2681, Ensena, B. C. 22800, Mexico.

4 Instituto Potosino de Investigación Científica y Tecnológica, División de Materiales Avanzados, San Luis Potosí, S.L.P., Mexico.

[email protected],[email protected],[email protected], [email protected], [email protected]

Keywords: Catalysts oxides, TOD method, transition metal, high activity, selectivity, NO reduction, CO.

NiO, CuO and ZnO catalytic materials were synthesized by thermal oxidative decomposition

(TOD) using Ni, Cu and Zn salts as precursors, in an oxidizing atmosphere. Catalysts were characterized

by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM)

and BET. The 3 catalyst were then tested for NO reduction with CO. NO reduction rate was in the range

of 0.42 to 574.2 x10−6 mol•s−1g−1, and activation energy in the range of 8 to 19 Kcal•mol−1K−1.

Catalysts show the following decreasing order of activity CuO>NiO>ZnO. CuO achieved 100 % NO

conversion at 275 ˚C with 94 % selectivity to N2.

P-005

CATALYTIC PYROLYSIS OF COCONUT SHELL TO OBTAIN CARBON PRODUCTS

Quintana-Melgoza J.M.1, a, Mizraim G. Granados-Fitch3, b and Ávalos-Borja M. 2,3,c


36

1 Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad, 14418, Parque Industrial Internacional Tijuana, Tijuana B.C. 22390, Mexico.

2 Centro de Nanociencias y Nanotecnología, UNAM, Apdo. 2681, C.P. 22800. Ensenada B.C. Mexico.

3 Instituto Potosino de Investigación Científica y Tecnológica, División de Materiales Avanzados. Camino a la Presa San José 2055, Lomas 4ta sec., C.P.78216, San Luis Potosí, S.L.P. México.


Keywords: Pyrolysis, Coconut shell, catalyst, reductive atmosphere, C.

The catalytic pyrolysis of coconut endocarp (coconut shell from Cocos nucifera L palm) has been

catalyzed by cobaltosic oxide (Co3O4) in hydrogen atmosphere at various temperature treatments in the

range of 300 to 800 °C. The reaction products were mainly amorphous carbon, SiO2, and possibly n-

diamond. The materials were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy

(EDS), scanning electron microscopy (SEM), infrared spectroscopy (IR), Raman spectroscopy (RS), and

electron energy loss spectroscopy (EELS). We thank CONACYT for a scholarship to Mizraim G. Fitch,

and financial support through grant CB-2010-01-151551. We are very grateful to E. Aparicio, E. Flores, I.

Gradilla, G.J. Labrada, A. Patron, B.A. Rivera, A.I. Peña and R. San Juan, for technical assistance. We

also thank MyDCI-FCQI-UABC, LINAN-IPICyT, IF-UNAM and CNyN-UNAM, for providing

laboratory support.

P-006

SYNTHESIS AND CHARACTERIZATION OF SUB-MICRODIAMOND ON SI(111) BY HF-CVD.

J. A. Montes a*, R. Garcia-Gutierrez b, M. Barboza-Flores b, R. Meléndrez b, O. E. Contreras c and R. Nemanich d,

a Departamento de Física, Universidad de Sonora, Hermosillo,Sonora,Apdo. Postal5-088, C.P. 8300, México

b Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal5-088, C.P. 8300, Hermosillo,Sonora,México

c Centro de Nanociencia y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, Baja California, México

d Department of Physics, Arizona State University, Tempe, AZ, 85287-1504, USA

[email protected]

Keywords: Nano-diamonds, thermoluminiscence (TL), dosimetry, biosensors.

Micro- and nano-diamonds have been studied for its thermo luminescence properties in dosimetry

field and also due to its no-toxic bio-compatibility diamond is has been used recently in the industry of


37

biosensors. In this paper, a novel method to synthesize sub-microdiamonds on silicon (111) by Chemical

Vapor Deposition utilizing a hot filament as activator at relative low pressures (~150 Torr) is reported.

Using a CH4:H2 mixture gases a thermal decomposition was conducted in a horizontal quartz-tube reactor

at 2200 °C temperature filament and 1000 °C temperature substrate yielding sub-microcrystallites

diamonds. The micro-diamond synthesized by this method have a spherical shape and consist of a mixture

of micro- and nano-sized crystallites. The diamonds synthesized in this work showed an excellent

6RAMAN and TL signals comparable to those obtained on the commercial nano-diamonds. Due to these

excellent properties, the diamonds obtained by this technique could be applied as-synthesized in the

biomedical industry.

P-007

PERFORMANCE IMPROVEMENT OF NANOMATERIALS BASED FREQUENCY DOMAIN SENSORS USING NUMBER THEORY.

Fabian N. Murrieta-Rico1,a, Vitalii Petranovskii2,b, and Oleg Yu. Sergiyenko3,c

1 Center for Scientific Research and Higher Education of Ensenada, Ensenada, Baja California, Mexico

2 CNYN-UNAM, Ensenada, Baja California, Mexico

3 Engineering Institute of Autonomous University of Baja California, Mexicali, Baja California, Mexico


Keywords: Sensors; frequency measurement; FDS; Zeolite; Number theory

One of the zeolite properties is the capacity of size and shape selective absorption of molecules

into their internal nanoporosity. Such molecular selectivity permits to detect very small concentrations of

specific compounds in gases mixture, if one will be able to estimate a mass change of zeolite crystal due

to adsorbed compound. To achieve this effect, a resonant element (i.e. quartz crystal) is coated with a

zeolite, and a change on the crystal’s resonant frequency due to the mass change produced in the zeolite

led to a proportional frequency shift. A resonant element that produces a change on its frequency as

consequence of another physical parameter is known as a frequency domain sensor (FDS). The

nanomaterials based FDS are capable of measuring chemical compounds concentration with high

precision and selectivity. In addition, the FDS output has some outstanding properties: high sensitivity,

high resolution, wide dynamic range, anti-interference capacity and good stability. However, in order to

get accurate values, such sensors require a high-resolution frequency measurement process. Most of the

frequency meters are not enough accurate, and required a sufficiently long fixed time for signal detecting.

For these reasons they are unable to use all the potential of nanomaterial’s based FDS. A new frequency


38

measurement technique, applying number theory, is proposed for using on this kind of sensors. Some

particular cases are examined.

P-008

ZnO NANOPARTICLES GROWN IN AMORPHOUS Zn2SiO4/SiO2 COMPOSITE FILMS DOPED WITH ALUMINUM AND PREPARED BY SOL-GEL.

H. Arizpe-Chávez1 , M. A. Hernández-Ochoa1 , J. Alvarado-Rivera1,2 , M. Flores-Acosta1, J. M. Yáñez-Limon2 and R. Ramírez-Bon2

1 Department of Physics Research, University of Sonora, 83190, Hermosillo Sonora, México

2 Department of Materials and Engineering Science CINVESTAV-Querétaro, Libramiento Norponiente No. 2000 Fracc. Real de Juriquilla C.P. 76230 Querétaro,Qro., México

[email protected]; [email protected]; [email protected]

[email protected]; [email protected]

Keywords: Sol-Gel; Composite Films; ZnO; Nanoparticles; structure characterization.

ZnO nanoparticles were synthesized in transparent TEOS-based SiO2 films doped with

Aluminum and prepared by the sol-gel method. We used Tetraethyl-orthosilicate (TEOS), aluminum and

zinc nitrates as cation sources, ethanol and water as solvents. The film depositions were carried out at

ambient conditions by dip coating at a withdrawal rate of 8 cm min-1 on corning glass substrates. After

dipping, the samples were dried at 2000 C for 10 minutes, and then thermally annealed at 300, 400 and

5000 C for 30 minutes. If no aluminum was included into the process, the films were amorphous, and

only showed the presence of Willemite (Zn2SiO4) when annealed at 5000 C. When Aluminum was added

into the solutions, crystalline ZnO grains started to form embedded into the amorphous matrix. The films

fabricated with a dopant concentration of Al/Zn = 0.0 at. %, 0.2 at. % and 1.0 at. %, were characterized

by XR diffraction, UV-VIS, IR Transmittance, XPS, and Photoluminescence. All the samples with a

thickness of about 1 m, showed a transmittance higher than 85 % over the visible wavelength region

and ZnO nanoparticles with sizes in the range from 4.6 to 24 nm were synthesized in the Aluminum-

doped films. The nanoparticles also showed energy band-gaps greater than the bulk, which in this case

was produced by expansive strain. In this work we show that amorphous willemite formed in TEOS-

based sol gel matrixes annealed at temperatures below 5000 C inhibits the growth of ZnO grains. The

addition of aluminum as a dopant breaks the zinc silicate linkages, allowing the formation of ZnO

crystalline nanoparticles. This work was supported by the University of Sonora through the Division of

Exact Sciences (Project number FEC-2012-03)

P-009


39

NITROGEN DOPING CARBON NANOTUBES.

G. Elizalde1, D. Shimomoto1, Z. Bedolla2, I. Del Real1, E. Cervantes3, A. Guerrero4,

D. Domínguez2, H. Tiznado2, G. Alonso2,a, O. E. Contreras2,b and J. M. Romo-Herrera2,c

1 Ingeniería en Nanotecnología FIAD-UABC, Ensenada B.C., México


3 FCFM-BUAP, Puebla Pue., México. 4 ESFM-IPN, México D.F., México.


Keywords: Nanotubes, doping, nitrogen, synthesis, spray-pyrolysis.

Current commercial interest in Carbon Nanotubes (CNTs) is mainly based on their mechanical,

electronic and thermal conduction properties among others. One manner to fine-tune such properties is by

the chemical modification of the CNTs, introducing non-Carbon atoms into the Carbon network in tiny

amounts, phenomenon known as doping. Here is presented the doping of CNTs by Nitrogen atoms during

synthesis, using the CVD spray pyrolysis technique. The main idea is to introduce a Nitrogen containing

organic precursor into the high temperature reactor (750 – 900 °C) during the synthesis. The synthesis

parameters were optimized in order to obtain the best yield-quality compromise. The obtained samples

were characterized by SEM, TEM, TGA, XRD and Raman spectroscopy, to evaluate the powders

characteristics in order to find the optimum parameters. The TEM images revealed a bamboo –like

structure of the CNTs, characteristic of Nitrogen doped CNTs, while XPS characterization presented the

Nitrogen peak. XPS spectrum allowed estimating the Nitrogen content around 1.8% with respect to

Carbon.We thank E. Aparicio, A. Tiznado, I. Gradilla, D. Domínguez, F. Ruiz and J.A. Díaz for technical

assistance; and projects DGAPA-PAPIIT IN-109612, DGAPA-PAPIIT IN-104714 and CONACyT

174689 for financial support.

P-010

DEVITRIFICATION BEHAVIOR OF AMORPHOUS METAL FOILS DURING SPARK PLASMA SINTERING

Boyao Zhang1,a, Olivia A. Graeve1,b



Keywords: Amorphous metals, spark plasma sintering, nanocrystallinity, devitrification

We present a detailed study of the devitrification behavior of Fe- and Ta-based amorphous metal

foils during sintering using spark plasma sintering. Samples of about ½ cm in thickness and ~20 mm in


40

diameter were prepared by stacking circles of the thin foil on top of each other, either directly aligned or

staggered with respect to a center position. The arrangement of the circles has an influence on the

devitrification behavior, with the stacked samples resulting in CFe2.5, B4Si, Fe3C, and hexagonal and

cubic carbon. The staggered samples resulting in B4Si, B13C2, and hexagonal graphite, according to

detailed X-ray diffraction (XRD) analysis. These results will be presented and analyzed. Microscopy of

the samples will also be presented and correlated to the XRD phases.

P-011

FUNDAMENTAL ANALYSIS OF REVERSE MICELLE STABILITY FOR CONTROLLED SYNTHESIS OF NANOPARTICLES

Hoorshad Fathi-Kelly1,2,a, James P. Kelly1,2,b, Olivia A. Graeve1,2,C

1 Kazuo Inamori School of Engineering, Alfred University, Pine Street, Alfred, NY 14802



Keywords: Reverse micelles, microemulsions, dynamic light scattering.

Reverse micelle synthesis is a solution-based synthesis technique that uses confined water

nanodomains in a bulk oil phase via self-assembly of surfactant molecules at the water-oil interface. This

technique can be used for synthesizing functional nanoparticles for a wide variety of applications. The

technique can be used to make unagglomerated nanoparticles with a narrow size distribution or

compositionally layered nanoparticles, for example. Although some aspects of this synthesis method are

well understood and agreed upon, other aspects remain based on trial-and-error modifications. In this

study, we use model systems to study the fundamental aspects of electrostatic interactions on reverse

micelle synthesis. One of the fundamental aspects to be studied includes how solutes affect the size and

stability of reverse micelles and defines concentration stability limits. The interaction between a

precipitated particle in suspension and the stability of the reverse micelle that contains the precipitate is

also evaluated to define precipitation limits. The effect of surfactant substitution, non-aqueous solvent

substitution, and the water to surfactant ratio is evaluated for optimizing the combination of solute

concentration stability and precipitation limits that can be used for the design of controlled nanoparticle

formation.

P-012

PREPARATION OF HEXABORIDE NANOCUBES FOR HYDROGEN STORAGE APPLICATIONS


41

James T. Cahill1,a, , Olivia A. Graeve1,b



Keywords: Hexaborides, hydrogen storage, combustion synthesis.

Nanocubes of CaB6, CaSrB6 and SrB6 have been synthesized using a low-temperature combustion

synthesis process. While traditionally used for the preparation of oxides, combustion synthesis has also

been shown to effectively produce boride nanopowders, although this is the first example of calcium and

strontium hexaborides prepared in this fashion. Combustion synthesis has several advantages over

traditional methods including low temperature, fast heating rates, short reaction times and no need for a

protected atmosphere. The (M)B6 powders were prepared using metal nitrates, organic fuels

(carbohydrazide or urea) and amorphous boron as precursors. The reactions were carried out in a box

furnace at temperatures below 400°C, a crucial step for obtaining sub-micron particles. After synthesis,

the powders were washed to remove any undesirable borate phases and then characterized by X-ray

diffraction, scanning electron microscopy and dynamic light scattering. Hexaboride compounds exhibit a

cubic crystal structure with octahedra of boron atoms forming a “cage” around the respective metal ion.

The highly covalently bonded boron atoms make hexaborides thermally and chemically stable, while the

metal ion located in the center of the unit cell can donate electrons to the structure, imparting a

semiconductor character in the case of Ca2+ and Sr2+. Modification of dopants can lead towards control of

internal ions in the structure that can serve as cages for hydrogen storage.

P-013

ANALYSIS OF GRAIN SIZE AND PARTICLE SIZE IN CERAMIC POWDERS

Keyur Karandikar1,a, Olivia A. Graeve1,b

1Department of Mechanical and Aerospace Engineering, University of California, San Diego 9500 Gilman Drive – MC 0411, La Jolla, CA 92093-0411, USA


Keywords: Zirconium oxide, cerium oxide, spark plasma sintering, dynamic light scattering, crystallite

size, nanopowders.

We present a study focused on obtaining a better understanding and correlation between the

particle size of various ceramic powders and the grain size of the sintered specimens. Ceramic powders

of ZrO2 and CeO2 of various particle sizes have been used in this study. The powders were sintered by

spark plasma sintering, a process that involves the use of a pulsed DC current and external pressure to


42

cause localized Joule’s heating.The ceramic powders have been characterized for particle size distribution

using dynamic light scattering, while the grain sizes of the sintered specimens were obtained through

image analysis by scanning electron microscopy. The result of the study is to develop an empirical

relation/model between these two size distributions. This result is expected to play an important role in

optimizing different parameters of the SPS process to develop advanced future ceramic nano-composites.

In addition, it will help in understanding microstructural evolution, densification and other

mechanical/physical properties during ceramic powder processing. One of the specific applications for

our study is the development of multiphase nano-crystalline ceramics for nuclear reactors.

P-014

MORPHOLOGICAL CHARACTERISTICS OF GOLD/COBALT JANUS NANOPARTICLES PREPARED USING VARIOUS SUBSTRATES

Kyungah Seo1,a, Olivia A. Graeve2,b



Keywords: Janus particles, colloidal processing, metal deposition.

Ionic polymermetal composites (IPMC) are polymeric materials coated with conductive thin

metal layers such as gold or platinum. These materials can exhibit mechanical deformation when applying

external electric fields. By replacing gold/platinum thin layers of IPMC with magnetic/plasmonic

bimetallic Janus nanoparticles, the composite could be actuated with magnetic fields as well as electric

fields, which can bring huge advantages to the IPMC device technology. Janus particles are well known

to have unique physical/chemical properties and directionality within a single particle because of their

asymmetry. Especially, Janus particles with magnetic materials are very promising due to their easy and

reliable control on particle rotation/moving directions with external magnetic fields. In this study,

magnetic/electric bimetallic Janus nanoparticles were prepared with one side gold (electric) and the other

side cobalt (magnetic) via spin coating and electron beam deposition methods. Various planar substrates

such as glass, NaCl and anodic aluminum oxide (AAO) substrates and polymer sacrificial layers were

used to study the electric/magnetic property changes induced from size and shape changes of the final

particles. TEM/SEM and dynamic light scattering (DLS) were performed to characterize the sizes, shapes,

and morphologies of the synthesized particles.

P-015


43

SYNTHESIS AND DETERMINATION OF LUMINESCENT PROPERTIES OF DOPED HYDROXYAPATITES

Luz Zavala1,a, Manuel Herrera Zaldivar,1,b Gustavo Hirata Flores,1,c Olivia A. Graeve1,2,d



[email protected],[email protected], [email protected], [email protected]

Keywords: Hydroxyapatite, luminescence, doping, nanoparticles.

This project aims to synthesize and characterize nanoparticles of HAp doped with rare-earth ions

(Eu, Ce, Tb, Tm, and Er) and to incorporate those nanostructures in glass scaffolds. Hydroxyapatite

(HAp) is one of the primary constituents in biological hard tissue and has a huge interest in the medical

industry, mainly for its applications in bone regeneration. The doping of rare earth HAp is of particular

interest because of its potential use as a fluorescent probe for medical treatments, this due to its excellent

luminescent properties. In this project, HAp powders doped with Eu and Tm at different concentrations

were synthesized by combustion synthesis with dopant concentrations of 2% and 5% mol. The powders

were thermally treated at 650°C, 700°C and 750°C and characterized using scanning electron microscopy

and luminescence spectroscopy, concluding that the best temperature to achieve the proper morphology is

at 750°C degrees. Higher calcination temperatures promote higher crystallinity of the powders, but there

is a decrease of the HAp [Ca10(PO4)6(OH)2] and an increase in the quantity of the whitlockite phase

[Ca3(PO4)2, β-TCP]. Also, it was found that the Eu luminescence distribution in the HAp powders is not

homogeneous, thus, there is an inhomogeneous distribution of dopants.

P-016

MOLECULAR DYNAMICS SIMULATIONS OF REVERSE MICELLAR SOLUTIONS WITH SOLVATION SALTS

Rafael Navarro1,a, Victor R. Vasquez2,b, Olivia A. Graeve1,c


2 Department of Chemical and Materials Engineering, University of Nevada, Reno 1664 N. Virginia Street – MS 388, Reno, NV 89557, USA


Keywords: Molecular dynamics, reverse micelles, microemulsions, AOT, isooctane.


44

Reverse micellar systems consisting of water, AOT, and isooctane are studied using molecular

dynamics (MD) simulations. We have examined the distribution of micelle size as the ratio of water to

surfactant is varied as well as the addition of model salts. We will present the critical value of the ratio

that produces the two dynamical regimes that occur at low and high ratios of water to surfactant. At low

ratios, there is a significant deviation from sphericity and there exists oscillations of the structure. At high

ratios, the spherical radius increases with the ratio of water to surfactant. The positions of AOT molecules

relative to the center of the micelle have been tracked at high salt concentrations. High salt concentrations

lead to a decrease in micelle size due to a disruption in the solvation layer. The free energy of the system

has been measured with simulation time to ensure equilibrium of the system.

P-017

FABRICATION OF MONO-SIZED HEMISPHERICAL MESOPORES ON GOLD-COATED POLYSTYRENE PARTICLE SURFACES

Seongcheol Choi1,a, Rafael Vazquez-Duhalt2,b, Olivia A. Graeve1,2,c



[email protected],[email protected],[email protected]

Keywords: Nanoparticles, polystyrene, mesoporosity.

Gold-coated PS (polystyrene) particles with mono-sized hemispherical mesopores on the surface

were prepared to investigate their use as scaffolds for support of CPO (chloroperoxidase) enzymes. First,

mono-sized polystyrene particles were fabricated in water by soap-free emulsion polymerization. Second,

mono-sized silica nanoparticles were synthesized in water with L-lysine which acts as a dispersing agent

and a catalyst. Third, this mono-sized silica nanospheres were decorated on the polystyrene spherical

particles, which were functionalized with PVP (polyvinylpyrrolidone). Subsequently, the hydroxyl

groups on the surface of silica nanospheres on the PS particles were modified to methyl groups to make

their surface hydrophobic. Gold was then deposited from HAuCl4•4H2O using dimethylamine-borane as a

reducing agent onto the surface of PVP-adsorbed PS particle. Finally, the silica nanospheres were washed

from the mesoporous gold layer with hydrofluoric acid. The morphology of the resulting mesoporous

particles will be described and process control will be analyzed.

P-018

SYNTHESIS OF MAGNESIUM POWDERS OF UNIQUE MORPHOLOGIES


45

Shuang Qiao1,a, Olivia A. Graeve1,b


[email protected],[email protected]

Keywords: Magnesium, nanoparticles,

We present a synthesis methodology for the preparation of magnesium/gold nanoparticles of

unique morphologies prepared using a galvanization process. Using a magnesium ribbon and Pt/Rg gauze

as anode and cathode, an electrolysis process was conducted in non-hydrous THF with 0.1M

tetrabutylammonium bromide and 70mg of magnesium acetate, dissolved in THF by stirring. During the

process, a current of 0.8mA was applied. The experiment was conducted in an inert atmosphere to protect

from oxidation. After galvanization, the magnesium powders were coated with gold to protect from

oxidation once the powders were exposed to air. A variety of techniques were used to characterize the

powders, including scanning electron microscopy, dynamic light scattering, and X-ray diffraction.

Results from the analysis will be presented and discussed.

P-019

SOLVOTHERMAL PROCESS FOR THE PREPARATION OF DOPED ULTRA-HIGH TEMPERATURE CARBIDE CERAMICS

Tianqi Ren1,a, Olivia A. Graeve1,b



Keywords: Tantalum carbide, solvothermal synthesis, dynamic light scattering, doping.

Many of the Group IV-V transition metal carbides such as tantalum carbide (TaC), hafnium

carbide (HfC), zirconium carbide (ZrC),and niobium carbide (NbC) are classified as ultra-high

temperature ceramics (UHTCs) because of their high melting temperatures (usually greater than 3300 K).

These UHTCs are of increasing interest in aerospace applications such as hypersonic vehicles and

scramjets due to their excellent thermo-mechanical properties. In this project we are exploring the

possibility of morphology control of transition metal carbides through dopant incorporation and focusing

on the TaC system. We are aiming at fabricating highly faceted parallelepiped or cubic TaC particles

with less than 200 nm in size. We have employed the solvothermal synthesis method to produce nano-

sized TaC powders from several precursors including tantalum chloride (TaCl5), carbon, and lithium.

Quartz test tubes and a silicone oil heating bath were utilized to conduct the ignition process. Reaction

products were washed using acids to obtain final powders. Combining the results from both dynamic light


46

scattering (DLS) and scanning electron microscopy (SEM), the as-synthesized powders possess particle

sizes ranging from 100 to 200 nm. Currently,we observe a small amount of oxidation throughout the

samples, but TaC is the dominant phase in all samples. We have started to observe promising

morphological changes under SEM for 15 at% doping of the TaC having cubic-like sharp-edged particles.

P-020

CATHODOLUMINESCENCE OF GaN NANORODS AND NANOWIRES GROWN BY THERMAL EVAPORATION

G. Guzman1,a and M. Herrera1,b



Keywords: Gallium nitride, nanowires, point defects.

GaN nanorods and nanowires have been grown by thermal evaporation of GaN on Au/Si (100)

substrates. The nanorods recorded a surface decorated with numerous grains with an average size of about

100 nm. The nanowires grew onto the surface of the nanorods exhibiting multiple bends along them.

TEM measurements revealed the formation of irregular porous and a polycrystalline structure in the

nanowires with diameter higher than 100 nm, while the nanowires with lower diameter showed a tubular

structure with wall thickness of 10 nm. The luminescence of the samples recorded three bands centered at

about 2.1, 2.74, and 3.2 eV, attributed to the GaN yellow emission and to the blue and UV emissions of

the β-Ga2O3, respectively. Ga-ion irradiation in samples revealed a decrease in the intensity of theβ-Ga2O3

blue emission attributed to the elimination of gallium vacancies. A thermal annealing treatment at 800 C

in N2 atmosphere generated a quenching of the GaN yellow emission, due to the elimination of nitrogen

vacancies.

P-021

CARBON NANOTUBES SYNTHESIS: OPTIMIZING THE SPRAY PYROLYSIS SYSTEM

Juan A. Salas1, Zaira Bedolla2, Oliver Becerra2#,, Oscar E. Contreras2,a, Gabriel Alonso2,b and J. M. Romo-Herrera2,c

1 Ingeniería en Materiales ITM, Morelia Mich., México

2 CNyN-UNAM, Ensenada B.C., México. # Lic. Nanotecnología CNyN-UNAM.


Keywords: Nanotubes, synthesis, optimization, spray-pyrolysis.


47

Current commercial interest in Carbon Nanotubes (CNTs) is mainly based on their mechanical,

electronic and thermal conduction properties; incorporating them in diverse products such as batteries,

sporting goods, automotive parts, boat hulls or water filters among others. The present stage in the CNTs

field calls for designing, learning and implementing processing methods in order to prepare functional

and manageable materials that can make the most of CNTs properties. A first step towards these

processing methods is to improve the raw material quality directly from synthesis, increasing the

structural properties of the CNTs and minimizing the by-products (iron carbides or amorphous carbon

among others) contained in the obtained powders. Here we present the optimization of the synthesis

system to increase the overall quality of the raw CNTs powders obtained following the CVD spray

pyrolysis approach. We analyzed the effect of avoiding the entrance of residual reactive during the

heating/cooling period. Once improved that, we adjusted the synthesis parameters (temperature and

reactive feeding flux) to obtain the best overall quality – yield compromise for the samples synthesized.

Samples overall quality was evaluated by Raman spectroscopy, TGA, XRD, SEM and TEM. We thank E.

Aparicio, A. Tiznado, I. Gradilla, F. Ruiz and D. Domínguez for technical assistance; and projects

DGAPA-PAPIIT IN-109612, DGAPA-PAPIIT IN-104714 and CONACyT 174689 for financial support.

P-022

DESIGN AND CHARACTERIZATION OF A CARRIER SYSTEM FOR BIOACTIVE SUBSTANCES, USING NANOPARTICLES OF CHITOSAN AEROGELS

Caro León Francisco Javier,a, Lizardi Mendoza Jaime,b, Carvajal Millán Elizabethb, López Franco

Yolanda Leticiab, Clamont Monfort Gabriela Ramosb, Goycoolea Valencia Francisco Mc

a,b Centro de Investigación en Alimentación y Desarrollo A.C., Carretera a La Victoria km 0.6, Hermosillo, Sonora, México, C.P. 83304.

c Westfälische Wilhelms-Universität Münster, Schlossplatz 2, 48149 Münster, Germany

[email protected], [email protected], [email protected], [email protected],


Keywords: Chitosan, aerogeles, nanoparticles, supercritical drying.

In this work, a system of chitosan nanoparticles of aerogels was produced using supercritical

drying with carbon dioxide (CO2). To obtain such systems, a colloidal water suspension of chitosan

nanoparticles was produced by ionic gelation (Calvo et al., 1997) with sodium tripolyphosphate. Different

parameters were evaluated in order to obtain nanoparticles with small hydrodynamic diameter and low

polydispersity, like TPP concentration, pH and temperature (the hydrodynamic diameter was determined

by dynamic light scattering). Later, the supercritical drying with CO2 was performed to produce the

nanoparticles of aerogeles and the conditions of temperature and pressure were standardized. This


48

technique is could be used to obtain a mesoporous structure in the nanoparticles, in which is possible to

incorporate molecules into their cavities. Once the systems are produced, their properties such as surface

area and pore size, particle size, surface charge and morphology were studied by BET porosimetry

technique, particle dynamic light scattering, Z-potential, electron microscopy and atomic force

microscopy.

P-023

ATOMIC FORCE MICROSCOPY FOR THE MICRO/NANOSCALE ANALYSIS OF ERYTHROCYTES: MICROCYTOSIS AND MACROCYTOSIS

Gaytan-Ordaz1, a, J. Navarro-Henze3, b, E. Silva-Campa1, c, K. Santacruz-Gomez2, d and M. Pedroza-Montero1, e.

1 Departamento de Investigación en Física, Universidad de Sonora, Hermosillo, Sonora, 83000, México

2 Departamento de Física, Universidad de Sonora, Hermosillo, Sonora, 83000, México

3 Hospital General Zona No 2 del IMSS, Hermosillo, Sonora, 83000, México

[email protected], [email protected], [email protected], [email protected], [email protected].

Keywords: Macrocytosis, microcytosis, AFM, MCV, morphometric parameters.

Microcytosis and macrocytosis refers to a cells blood condition that describes erythrocytes small

and larger than normal, together with a decrease and increase of mean corpuscular volume (MCV)

respectively. This, condition affects the cell function that coexist with different pathologies. Despite the

easy identification of these cellular alterations via microscopic analysis and hematic biometry, there is no

description of their morphometric and mechanical changes in nanoscale. Atomic force microscopy (AFM)

is powerful nanobiomechanical tool considering its high-resolution topographical imaging approach to

biological samples in their physiological conditions. This work compared morphometric parameters such

as SA (surface area), and depth with the MCV, as well as the morphological alterations in nanoscale.

Some lines patterns of membrane central depth associated to MCV in damaged surface were found. These

results have shown another perspective of analysis in micro and macrocytosis on the use of AFM.

However to obtain integral structure-function relationship further studies are required, especially bio-

nanomechanics.

P-024

NANOCRYSTALLINE CELLULOSE AS REINFORCEMENT OF HYDROGELS WITH POTENTIAL APPLICATION AS BIOMATERIAL

Piña-Acosta, Juan Antonio1,a,Zizumbo-López, Arturo1,band Licea-Claverie, Ángel 1,c


49

1 Centro de Graduados e Investigaciónen Química. Instituto Tecnológico de TijuanaA.P. 1166, Tijuana, B. C., Mexico. 22000


Keywords: Nanocrystalline cellulose, Hydrogels, Nanocomposites, Biomaterials.

Nanocrystalline cellulose (NCC) is a high crystalline nanomaterial suitable for structural

reinforcement due their excellent mechanical properties. NCC is characterized by a high aspect ratio, high

resistance to bending (10 GPa), high Young’s modulus (150 GPa), high superficial area, low density, low

extension to break, very low thermal expansion coefficient, biodegradability, and biocompatibility.

Hydrogels are a tridimensional network structure of polymeric chains containing hydrophilic groups that

allow the swelling of the network in aqueous environments. The current polymerization techniques for

hydrogel preparation can cause flaws in the microstructure and lead to mechanical failures. The

introduction of a nanometric material in the microstructure of the hydrogels like fillers may reinforce and

enhance the mechanical properties of the polymeric network in aqueous environments typical of body

fluids. In this work NCC was obtained by acid hydrolysis from commercial cotton.The physical and

chemical properties of NCC were assessed by dynamic light scattering (DLS), polarized light microscopy

(PLM), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). AFM micrographs show

that nanofibers were obtained of various lengths from 100-400 nm and a diameter between 5-10 nm.

Hydrogels of 2-hydroxyethylmethacrylate (HEMA) and modified by addition of polyethylene glycol

methyl ether acrylate (PEGA) were prepared by photopolymerization in aqueous systems. A methodology

was developed to disperse NCC into the reaction mixture to prepare transparent hydrogels of PHEMA,

PHEMA-co-PEGA, and PHEMA with NCC fiber inclusions. The chemical properties as well as their net

parameters were evaluated by infrared spectroscopy, TGA and equilibrium swelling measurements.

Results demonstrate that the swelling capacity and average molecular weight between crosslinks changed

as a function of NCC content and also as a function of PEGA content.

P-025

MAGNETIC, DIELECTRIC AND STRUCTURAL INVESTIGATIONS IN TBMNO3 MULTIFERROIC POLYCRYSTALS

Ivair A. Santos1,a, Gustavo S. Dias1,b, Luiz G. D. da Silveira1,c, Luiz F. Cótica1,d, D. Garcia2,e, and José A. Eiras2,f

1 Department of Physics, State University of Maringá. Maringá – PR. Brazil. 87020900

2 Department of Physics, Federal University of São Carlos, São Carlos – SP. Brazil. 13565905

[email protected],[email protected],[email protected],[email protected], [email protected], [email protected]


50

Keywords: Multiferroic, Magnetoelectric, Neutron Diffraction.

TbMnO3 has attracted considerable interest due to the interesting and intriguing physics that

beyond its multiferroism. Furthermore, its potentialities for multifunctional devices application have also

attracted special attention, mainly focusing magnetically or electrically tunable devices. TbMnO3 is a

multiferroicmagnetoelectric material at cryogenic temperatures due to a transition between two distinct

magnetic states and, in single crystals, a paramagnetic-antiferromagnetic transition is observed at TN ~41

K. Moreover, at 27 K,a polarization vector arises in the c – axes direction of the orthorhombic crystal. It

is worth noting that in TbMnO3 single crystals the polarization flops into the a direction when a magnetic

field (higher than 4 T) is applied along the a or b directions, while the polarization is suppressed in the c

direction of the orthorhombic cell. In this work, TbMnO3 polycrystals, calcined and sintered under

controlled atmospheres (oxygen or argon), were submitted to structural (X-ray and Neutron diffraction),

dielectric and magnetic investigations. The results revealed that the appearing of the above mentioned

magnetic transitions, as well as specific dielectric relaxations, as those reported for single crystals, are

extremely dependent of the atmosphere of synthesis. Structural characterizations revealed strong ionic

Tb-O and Mn-O bonds and stable Mn3+ and Tb3+ valence states in all studied samples.

P-026

SYNTHESIS OF ACID CORE – POLY(ETHYLENE GLYCOL) SHELL NANOGELS BY SOAPLESS EMULSION POLYMERIZATION

Díaz Duarte-Rodríguez Melissa1a, Cortez-Lemus, Norma Aidé;1b Zizumbo-López, Arturo;1cLicea-Claveríe, Angel1*

1 Centro de Graduados e Investigación en Química. Instituto Tecnológico de Tijuana. Apdo. Postal 1166. Tijuana, B. C. 22000, México.


Keywords: Emulsion polyemrization, core-shell nanogels, pH sensitive polymers.

"Smart" hydrogels are chemically crosslinked polymer networks that have the ability to respond

to external stimuli (such as changes in temperature, pH, etc.). If these polymer networks have dimensions

on the nanometer scale they are called nanogels, which in addition to reducing their response time

(expansion-contraction) acquire different properties than the macroscopic material (defined spherical

shape, more resistance, the ability to trap other molecules inside, among others). Nanogels are studied in

various fields of science and technology, finding potential applications as: fillers and coatings, drug

delivery systems, among others.pH-sensitive nanogels are interesting because their contraction and

expansion is sensitive to changes in pH of the environment. This sensitivity can be achieved using

polymers containing acid groups that ionize in a basic environment. Nanogels can also be used as fillers


51

in dental composites because the structure of a three-dimensional network can physically join to the

network structure of the secondary material creating an interpenetrating network with greater strength

than that observed in the regular material, while reducing the shrinkage stress commonly observed in

photo curable materials. In this work acid nanogels with core of poly(2-methacryloyloxybenzoic acid)

(2MBA) and polyethylene glycol methyl ether methacrylate (PEGMA) shell were synthesized by

emulsion polymerization without surfactant varying the mass ratios of PEGMA:2MBA; the mol

proportions of crosslinking agent and initiator, the temperature and pH of the reaction medium and

reaction time in order to obtain core-shell nanogels of diameters from 50 to 350 nm. Nanogels were

characterized by dynamic light scattering (DLS), infrared spectroscopy (FTIR), nuclear magnetic

resonance spectroscopy (NMR), thermogravimetric analysis (TGA) and atomic force microscopy (AFM).

Results show that the title nanogels were obtained with the desired size by adjusting the synthetic

conditions.

P-027

FORMATION OF SUPRAMOLECULAR NANOSTRUCTURES BY HOST-GUEST INTERACTION USING UREAS BENZAMIDES AS ANION RECEPTORS

Moreno Valle Ramírez Bibiana1,a, Ochoa Terán Adrián2,b

1 Instituto Tecnológico de Tijuana, Ingeniería en Nanotecnología, B.C., México

2 Centro de Graduados e Investigación en Química (CGIQ), Tijuana B.C., México.

[email protected], [email protected].

Keywords: Supramolecular complex, chromophore, anion.

In recent years research in supramolecular chemistry as an important part of anion coordination

nanochemistry and has experienced tremendous growth under the important role of the anions in the

biological world. They are also key players in environmental issues, such as phosphate (linked to

eutrophication of rivers) or nitrate (which metabolites can be carcinogenic) present in water as a result of

high fertilizer use. This work aims at the evaluation of a group of ureasbenzamides as selective anion

receptors to form supramolecular host-guest complexes with potential application in water treatment.

Analytical techniques to evaluate their efficiency were UV -Vis spectrometry and molecular fluorescence,

due to the optic properties of these receptors. The design of these receptors considered a combination of

the positions of the urea groups and benzamide (ortho and meta), and the structure of the chromophore

groups naphthyl and nitrophenyl, yielding a group of four compounds which were evaluated using the

above techniques; doing titrations with tetrabutylammonium fluoride (TBAF) and tetrabutylammonium

bromide (TBAB) solutions. The analysis results of the spectrophotometric titrations determined that


52

receptors on meta position relative to the chromophore favor the formation of a supramolecular complex

between the urea and the anion, compared with those who were in the ortho position.

P-028

PHOTOVOLTAIC EFFECTIN FERROELECTRIC BISMUTH FERRATE THIN FILMS

E. Martinez1, J. M. Siqueiros2,a, M. P. Cruz2, J. J. Gervacio2, M. A. Curiel3.

1 Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada.

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km. 107, Carretera Tijuana-Ensenada 22860, Ensenada, B.C., México

3 Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez S/N CP 21280, Mexicali, México.

[email protected]

Keywords: Domain walls, photovoltaic effect, ferroelectric, BiFeO3, substrate.

In recent years, research on the photoelectric properties of non-centrosymmetric materials has led

to the discovery of the "anomalous" photovoltaic effect (APVE) in such materials. The anomaly is

manifested by the appearance of a steady-state current in a short-circuited ferroelectric, under illumination

with light of wavelengths corresponding to itsoptical absorption range. When compared with the well-

known photovoltaic effect in semiconductors, the principal difference is the electron-hole separation

mechanism. In the case of the non-centrosymmetric materials, APVE will be strongly related to the

existence of periodic domain structures, with domain walls in the nanoscale range. The photo generated

voltage will turn out to be additive with every domain in the film contributing equally to the measured

value between the electrodes. In 2011, Jan Seidel et al described the photovoltaic effect in BiFeO3 (BFO)

thin films obtained through the technique of chemical vapor deposition. 71° and 109° domain structures

were obtained, their APVE characterized and a plausible explanation of the physical phenomenon was

offered. In this study we present work in progress towards the characterization of APVE in BFO thin

films prepared by an ion sputtering technique, starting from the preparation of the BFO sputtering target.

The ceramic was prepared by the traditional solid state method where a 94% density relative to theoretical

value was obtained. The preparation of suitable substrates is crucial to the experiment and is described

here with detail. Single crystal SrTiO3 slabs were etched in a 20% hydrofluoric solution for 14 minutes

and annealed afterwards at 950oC for 150 minutes. The results are presented in Figures 2 and 3 and are

correlated with the preparation conditions. The epitaxial BFO films are expected to grow 71º or 109º

oriented domains depending on the crystallographic orientation of the substrate.


53

P-029

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF IRON OLIVINE LITHIUM PHOSPHATE

Joel O. Herrera Robles1,a, Luis E. Fuentes Cobas2,b, Sebastián Díaz de la Torre3,c,Héctor Camacho Montes1,d

1 Universidad Autónoma de Ciudad Juárez, Cd. Juárez, Chih., México

2 Centro de Investigación en Materiales Avanzados, Chihuahua, Chih., México

3 Instituto Politécnico Nacional, Cd. México, México

[email protected],[email protected],[email protected], [email protected],

Keywords: Nanoparticles chemical synthesis, Rietveld refinement, spark plasma sintering

The iron olivine lithium phosphate is a multifunctional material with magnetoelectric and

multiferroic properties. If carbon is added to form a composite LiFePO4-C, electrochemical properties can

be obtained, then, this material is a good candidate for battery cathode. Even though, the promising

applications and the interesting properties of this system, the attention received in the literature is

relatively low. The level of difficulties to synthesize this material can be considered as high because of

the rapid iron oxidation and the manipulation of reducing atmosphere. In fact, only few authors report the

synthesis of the pure phase. In the present work, nanostructured LiFePO4 is sought. A combination of sol

gel chemical method, for obtaining nanoparticles, and spark plasma sintering (SPS), for avoiding grain

growth during firing and keeping the nanostructured ceramics, is implemented. Nanostructured LiFePO4

is a field of interest that deserves attentions. Herein, the synthesis and X-Ray characterization is reported.

According to X-ray diffraction patterns refined by the Rietveld method, LiFePO4is obtained almost pure

after calcination in a reducing 10% H2 – 90% Ar atmosphere. After obtaining the ceramic sample by SPS,

the phase composition remains and low grain size can be observed.

P-030

THERMOSENSITIVE STAR POLYMER OF POLY (N-VINYL CAPROLACTAM) OF 4 ARMS AND BIODEGRADABLE CORE OF POLY (Ε-CAPROLACTONE)

Montoya-Villegas Kathleen A1,a, Cortez-Lemus, Norma A*1,b, Licea-Claverie, Ángel1,c

1 Centro de Graduados e Investigación. Instituto Tecnológico de Tijuana. Apdo. Postal 1166. Tijuana, B. C. 22000, México.


Keywords: Star polymers, copolymer, thermosensitive, biodegradable, polymerization RAFT, ROP.


54

The star polymers have attracted considerable interest because of their three-dimensional form,

the architecture highly branched, and some of their improved properties as compared to linear polymers;

these stars are polymer molecules branched in which a single branch point elicits multiple linear chains

also if these have a hydrophobic core, they could store poorly soluble drugs in the core when in an

aqueous medium. The polymer star is one of the most stable alternatives to carry and deliver drug at a

suitable location for a sensitive effect to changes in temperature, pH or other stimuli. It has been reported

in recent years that by controlled radical polymerization reversible addition-fragmentation chain transfer

(RAFT) is possible to synthesize star copolymers, showing to be the best option because, it has

applicability to a wide range of monomers, also is compatible with a variety of solvents and reaction

conditions, and shows high tolerance to impurities3. Moreover, incorporating the method of ring opening

polymerization (ROP) has been demonstrated to synthesize block copolymers feasibly star type with

biodegradable and biocompatible properties.In this work, the synthesis of copolymers in block star type

well defined are reported, with a biodegradable core of poly(ε-caprolactone) and thermosensitive arms of

poly(N-vinylcaprolactam). For this, the first experimental stage consist in the synthesis of a chain transfer

agent (CTA) trithiocarbonate type. Moreover, star polymers of poly(ε-caprolactone) were prepared by

polymerizing ROP. Next, the CTA and the multifunctional core is coupled via an esterification reaction,

and finally, the synthesized macroCTA was used for the controlled polymerization of N-

vinylcaprolactam, finally obtaining star copolymers of poly(ε-caprolactone)-b-poly(N-vinylcaprolactam),

biodegradable and biocompatible. Figure 1 shows the structure of the multifunctional macroCTA that

contains poly(ε-caprolactone) utilized to control polymerization NVCL.

P-031

DEVELOPMENT OF ULTRATHIN STRUCTURES BASED IN AMARANTH (AMARANTHUS HYPOCHONDRIACUS) PROTEIN AND PULLULAN, LOADED WITH NISIN A.

Soto-Martínez, Karen M.1, a, Herrera Martínez Etzuly T.1.Colchado Morales Sandra1; Mendoza Diaz Mendoza-Díaz, Sandra O.1,b. Hernández-Iturriaga, Montserrat1. Luna-Barcenas, Gabriel2. Loarca-Piña, Ma. Guadalupe F. 1.Gómez-Aldapa Carlos A.3.

1 Programa de posgrado en Alimentos del Centro de la República , Universidad Autónoma de Querétaro, Méxcio

2 Centro de investigación y de estudios avanzados del IPN, Cinvestav, Quéretaro, México

3 Instituto de Ciencias Exactas e Ingenierita, Universidad Autónoma del Estado de Hidalgo, México.


Keywords: Nanofibers, nisin A, antimicrobial,


55

Preventing food borne illness and food preservation are some of the main concerns of the food

industry, to achieve this purpose has conservation systems as it has developed in recent years, this process

is called bioconservation and is based on the use of microorganisms or their metabolic products to inhibit

or destroy undesirable microorganisms. Some of the metabolites produced by bacteria called bacteriocins

are defined as biologically active proteins and peptides that have antimicrobial properties against species

closely related to or members of the same species. Among the most representative bacteriocin in the food

industry is that Nisin has the drawback of instability to be in a food matrix, so that it requires an

encapsulation system that prevents the decrease of antimicrobial activity. The nanofibers can be used for

the protection of these compounds, in the present work amaranth protein fibers and loaded pullulan were

performed with two concentrations 5 and 10 mg / mL of nisin, obtaining smooth fibers, uniform and

flawless with diameters between 249.5 ± 9.87. It could be that the active observer dispatched uniformly

along the fibers. After the process of electrospinning fibers still retain their antimicrobial activity against

L. mesenteroides and L. sakei.

P-032

DEVELOPMENT OF ULTRATHIN STRUCTURES BASED IN AMARANTH PROTEIN USING SURFACTANTS NON IONIC THROUGH ELECTROSPINNING

Etzuly Herrera Martínez, Magaly Soto Martínez, Sandra Colchado Morales, Adriana Blanco Padilla, Sandra Mendoza Díaz1

1 Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Querétaro, Qro. 76010, México.


Keywords: Electrospining, nanofibers, amaranth protein, surfactants.

Electrospinning is a technique to produce polymer fibers from solutions with diameters

nanometric range. The electrospun nanostructures morphology is affected by the solution properties

(mainly by the viscosity, surface tension and conductivity of the polymer solution) and by the process

parameters (voltage, flow rate of the solution, tip-to-collector distance). The electrospinning of

biopolymer solutions has been proven to be difficult due to several factors such as the polycationic nature

of many biopolymers, the low chain flexibility which complicates chain entanglements (essential for fiber

formation) and their generally poor solubility in organic solvents. To improve the biopolymer solutions,

different surfactants have been added for various purposes, like to make compatible hydrophilic fillers

with hydrophobic matrices, more importantly, to improve the spinnability of polymer solutions, which are

normally a consequence of the reduction in their surface tension, therefore reduce fiber defects. The

objective of this work was developed and characterized electrospun fibers from amaranth protein isolate


56

(API) using different nonionic surfactants (Span 20, Tergitol, Triton X-100 and Tween 80). To

development of nanofibers by electrospinning was obtained using formic acid and mixtures of amaranth

protein:pullulan (50:50 w/w) and surfactants (Span 20, Tergitol, Triton X-100 and Tween 80) at 30%

w/w. The fibers were imaged by Scanning Electron Microscopy (SEM). The experimental results, the

nanofibers with larger diameter were with Triton X-100 (320 to 330 nm), while the Span 20 the surface

morphologies show nanofibers between diameters 180 to 220 nm, the nanofibers with Tween 80 and

Tergitol their diameters were between 220 to 250 nm. The different diameters of the nanofibers were

because the electrical conductivity increased and different morphologies were obtained, probably because

the high electrical forces favored weak entanglements in the polymer. These results suggest that the

surface morphologies of nanofibers changed with the addition of different surfactants non ionics.

P-033

PEG AND TREG COATED MAGNETIC NANOPARTICLES AS CONTRAST AGENTS FOR MRI

M.A. Mendez-Rojas1,a,S. Hidalgo2,4, E. Gutierrez3, E. Santillan1, A. C. Lopez1, R. Gonzalez4, J.L. Coffer4, P. Dies-Suarez5, A. Angulo1, G. Delgado-López6, J. Flores7

1 Departamento de CienciasQuímico-Biológicas, Universidad de las Americas Puebla, Mexico;

2 Universidad AutónomaMetropolitana-Izapalapa, Mexico, UK;

3 Universidad Autónomadel Estado de México, Mexico;

4 Texas Christian University, USA;

5 Hospital Infantil de México “Federico Gómez”, México;

6 Centro de Investigaciones Biomédicas de Oriente-IMSS, México; 7Benemérita Universidad Autónoma de Puebla, México.

[email protected]

Keywords: Magnetite, mri, spion, toxicity, imaging.

Super-paramagnetic ion oxide nanoparticles (SPIONs) are of interest due to their great potential

applicatirons in diverse fields such as biomedicine. In this work we have prepared SPION nanoparticles

using the polyol technique, evaluated their toxicity in vitro and in vivo, and characterized their magnetic

properties for MRI in vivo use. [Fe(acac)3] was used as their oxide precursor and thermally decomposed

at high temperatures in triethyleneglycol (TREG). Nano-sized magnetite particles (8-20 nm) were

prepared by an adaptation of the method proposed by Wei Cai et al. Cytotoxicity studies show no-toxicity

for the systems, and no tissue damage or physiological alterations were observed at the animal model. A

healthy rabbit injected with a suspension of SPIONs was scanned on a clinical 1.5 T Philips MR scanner.

Images were taken in 2D mode with a mFFE sequence. Relaxation time T2 was obtained from the MR


57

images. Images were obtained before contrast injection, 24 hours and 36 hours following SPIONs

administration. Signal decay at different Echo times for the prepared magnetic SPIONs, and different

contrast before and after contrast injection. It was visualized a concentration of the contrast in brain and

liver and the results were compared with images obtained from histopathology.

P-034

RECENT ADVANCES IN THE MULTIFERROIC PROPERTIES OF La-DOPED BiFeO3-PbTiO3.

Freitas V. F.1,2,a , TominagaT. T.1, MiyaharaR. Y.1, Cótica L. F.2,3,b , Garcia D.4,c, Eiras, J. A.4,dand Santos I. A.2,e

1 Departament of Physics, UniversidadeEstadual do Centro-Oeste – Unicentro, Guarapuava – PR,Brasil,

2 Department of Physics, UniversidadeEstadual de Maringá - UEM, Maringá – PR,Brasil

3 Department of Electric and Computer Engineering, University of Texas, 78249, San Antonio - TX, USA

4 Department of Physics, Universidade Federal de São Carlos, São Carlos - SP, Brazil


Keywords: Multiferroic, magnetoelectric, ferroelectric, piezoelectric

Multiferroic magnetoelectric materials, which exhibit coupled magnetic and ferroelectric orders,

are hard to find. In this way, La doped BiFeO3-PbTiO3 compounds (BFPT-L), that show ferroelectric,

piezoelectric, (weak/anti) ferromagnetic properties and magnetoelectric coupling at room temperature,

emerge as strong candidates for applications in smart advanced devices. However, for magnetoelectric

multiferroic applications can be realized it is necessary before to find the balance of

electric/magnetic/structural properties. In this way, diffraction studies were conducted by Rietveld

refinement of Neutrons (Helmholtz-Zentrum Berlin) and X rays (Brazilian Synchrotron Light Laboratory)

diffraction data. The studies reveal the origin of the ferroelectric distortion by looking for the covalent

bonds between A site (Bi, Pb and La) and the three neighboring oxygen atoms. Interestingly, the electric

and magnetic dipole moments form an angle with each other. This angle may be used as an order

parameter for investigating the magnetoelectric state/coupling in these materials. Furthermore, a strong

link between the structure of the material and its properties were observed and a control mechanism using

atomic modification with La was appointed.

P-035

CO2 ADSORPTION ON MEXICAN ERIONITE ZEOLITE WITH NANOPARTICLES OF CALCIUM


58

Corona Leobardo.1,a , Sánchez Andrés.2,b, Ruíz Sinuhe.3,c, Hernández M. Ángel.4,c

1,4 Departamento de Investigación en zeolitas, Posgrado en Ciencias Ambientales. Instituto de Ciencias de la Benemérita Universidad Autónoma de Puebla. México. P.C. 72570

2,3 Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla. México.

[email protected],[email protected], [email protected],[email protected]

Keywords: CO2, Adsorption, erionite zeolite, Ca nanoparticles.

Natural zeolite erionite of Agua Prieta, Sonora, Mexico was characterized in its texture by N2

adsorption and subsequently this material was used to adsorb CO2. The adsorption of CO2 was carried out

in this zeolite in its natural and exchanged State with CaCl2 salts at room temperature and during 24

hours. A gas chromatograph (GC) apparatus was used. Studied zeolites have been the substrate without

chemical treatment (ERIN) and erionite exchanged ionically with CaCl2, 0. 01N (250, 500 and 750 mL

each time). The interaction between the molecules of adsorbate (CO2) and the structure of the erionite

zeolite was evaluated through the isosteric heats of adsorption. The experimental adsorption data of CO2

in this zeolite were evaluated through of Freundlich, Langmuir and Dubinin-Astakhov equations in their

linear form. These zeolites have been characterized by XRD, SEM, FDRX, and HRADS technics. The

goal of this work is to study the adsorption capacity of natural zeolite erionite exchanged with CaCl2 in

order to adsorb CO2 at 473, 503, 543, 588 and 623 K. The isotherms obtained correspond to type I in the

IUPAC classification. BET specific surface area values obey the following declining trend: ERICa2 >

ERICa1 > ERICa3 > ERINAT. The same trend is followed by total pore volume (V∑). The functions of

pore size distribution (FDTP) of the erionite zeolite under study were obtained by the Dubinin-astakhov

method (DA). The filling of the supercavities of the erionite zeolite (in length 1.51 nm and width 0.63

nm) and their interconnections through a zigzag path represent the main contribution to adsorbed volume.

P-036

THE ROLE OF LIGAND AGENT IN CONIMO/AL2O3 NANOCATALYSTS FOR DEEP SULFUR REMOVAL

L. Pérez1,a, C. Suresh2,J. N. Díaz De León1, T. A. Zepeda1,S. Fuentes1, G. Alonso1,b

1 Centro de Nanociencias y Nanotecnología-U.N.A.M., Ensenada B. C. México

2 CSIR-Central Electro Chemical Research Institute, Karaikudi, India.


Keywords: Nanocatalysts, dibenzothiophene, deep hydrodesulfurization, ligand agent.

The use of low sulfur diesel is a global trend. Refineries are increasing the demand of catalysts

that enable the production of ultra-low sulfur diesel. As a result of analyzing the national behavior in


59

production of gasoline and diesel, through the years, it appears that these fuels up before 2008 were

different from sulfur-free fuels. This research emphasizes the role of a ligand agent in the synthesis of

CoNiMo/Al2O3nanocatalysts.Catalysts were applied for the dibenzothiophenehydrodesulfurization (HDS)

reaction. The complex ligand precursors were characterized by ultraviolet visible, infrared, Raman, and

thermogravimetric techniques. Four catalysts were prepared by co-impregnation technique, changing C:N

promoter ratio [C=Co/(Co+Ni)] and N=[Ni/(Co+Ni)]. We selected C:N ratio as a 65:35, 75:25, 85:15 and

95:05. Molybdenum was kept as a constant.The catalytic activity results was better for an optimum ratio

of C:N=95:05, which is in accord with DRX, N2 physisorption, and TEM characterizations. So, we

examine the effect of the complex ligand precursor decomposition, which has improve in metal dispersion

and reduce the metal-support interaction as an ultra-deep HDS kind nanocatalyst. The authors

acknowledge CONACyT for financial support (Project 117373) and the valuable technical assistance to J.

Peralta, M. Sainz, F. Ruíz, E. Flores, I. Gradilla, and E. Aparicio.

P-037

SYNTHESIS OF NANOPARTICLES WITH IRPERSISTENT LUMINESCENCE BIOCOMPATIBLES FOR DIAGNOSTIC IMAGING BY COMBUSTION

N. J. Zúñiga1,a, M.Barboza-Flores2,b,R.García2c ,R.Melendrez2d

1 Departamento de Física, Doctorado en Nanotecnología, Universidad de Sonora. Hermosillo, Sonora, 83000, México


[email protected],[email protected],crgarcia@cajeme,[email protected]

Keywords: Silicates, Persistent Luminescence, Europium, combustion.

The phosphorescence is an optical phenomenon from the excitation of a material with high

energy radiation, such as UV radiation, which produces an emission in the visible for prolonged periods

ranging from seconds to hours (LUMP). Most phosphors are represented by two known compounds as

aluminates and silicates, both doped with rare earths, the latter have been reported recently as luminescent

materials which emit in the near infrared, as is the case of CaMgSi2O6:Eu,Dy,Mn which has been used

with the different polymer covers which are biocompatible as in the case of PEG Polyethyleneglycol,

reporting good signal in vivo. However, these systems have a problem, the autofluorescence of cells or

tissues. Our team develops a new material which is synthesized by combustion, allowing to obtain a

match with LUMP IR emission of long times with some changes in the doping, the introduction of

praseodymium in the matrix of material, which will raise the intensity and the decay time of this new

silicate, leaving behind the autofluorescence.


60

P-038

MORPHOLOGICAL, MICRO STRUCTURAL AND POLARIZATION CHARACTERIZATION OF THE BARIUM TITANATE SYNTHESIZED BY MOLTEN SALTS.

J. M. Moxca-Mochca1,a, M García-Guaderrama2,b M. Herrera2,c , A. Durán2.

1 Universidad Autónoma de Baja California, Km. 103 carretera Tijuana-Ensenada. C. P. 2286, Ensenada, B. C.; México.

2 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 carretera Tijuana-Ensenada. Apartado Postal 14, C. P. 22800, Ensenada, B. C. México

3 Departamento de Química, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, CP 44430, Guadalajara, Jalisco, México.

[email protected],[email protected],[email protected] [email protected]

Keywords: Crystalline structure, microstructure, ferroelectric, dielectric properties.

Submicron BaTiO3 particles were obtained by molten salts synthesis (MSS) employing equimolar

mixture of NaCl/KCl as the ionic solvent (1:4 ratio). Temperature synthesis between 800oC and 1200oC

were tested in order to found the optimal size, crystalline structure and, thus the better physical properties.

The morphology and crystal structure were characterized by a combination of the SEM microscopy and

x-ray diffraction. The results showed that the morphology, size and crystal structure were dependent of

the synthesis condition. An increase of the crystallinity of the samples was obtained by post-annealing

treatment. In this work, the relation between synthesis-post annealing condition, structure, microstructure

and the polarization response were studied. Thanks are due to E. Aparicio for their technical assistance.

The work has been supported by PAPIIT-UNAM IN103213.

P-039

PROPERTIES OF COPPER-DOPED ZnTe THIN FILMS WITH APPLICATION ON TFT

G. Lastra1,*, M.A. Quevedo-Lopez2, A. Olivas3

1 PCeIM, Centro de Nanociencias y Nanotecnología-UNAM, CP. 22860, Ensenada, B.C. México.

2 Department of Materials Science and Engineering, University of Texas at Dallas, 75080, Richardson, Texas, USA.

3 Centro de Nanociencias y Nanotecnología-UNAM, CP. 22860, Ensenada, B.C. México.


Keywords: ZnTe; thin films; Cu doping; thin-film transistor.

ZnTe thin films were deposited on SiO2 substrate by pulsed-laser deposition (PLD) at room

temperature. The ZnTe films were immersed in different concentrations of Cu(NO3)2-3H2O solutions for


61

1 minute, then heated at 200 and 300 °C in a N2 atmosphere. The X-ray diffraction (XRD) showed the

hexagonal and orthorhombic ZnTe phases when the copper-doped films were heated at 200 and 300 °C

for 10 minutes respectively. The sheet resistance of the undoped ZnTe films decreased linearly from 1.77

× 1010 to 3.92 × 104 Ω/ and the resistivity decreased from 2.26 × 105 to 3.20 × 10-1 Ωcm when they

were immersed in 6, 7, 9, 11, 13, 15 mg Cu(NO3)2-3H2O solutions. The films immersed in 15 and 60 mg

of Cu(NO3)2-H2O solutions had similar values of sheet resistance ~104 Ω/, resistivity ~10-1 Ωcm,

specific contact resistance ~10-4 Ωcm2, and hall mobility 5 cm2/Vs. Also, the copper-doped conditions

were used to dope the source and drain bias to make a thin-film transistor of ZnTe (TFT) by

photolithography.

P-040

LUMINESCENCE IN CaAl2O4:Eu2+, Dy3+ PREPARED BY COMBUSTION SYNTHESIS.

Rafael Garcia-Gutierrez1,a, Marcelino Barboza-Flores1,b, and Oscar E. Contreras2,c

1 Department of Research in Physics, University of Sonora, Hermosillo Sonora, Mexico 83000

2 Center of Nanosciences and Nanotechnology, National Autonomous University of Mexico, Ensenada B.C., Mexico, 22860


Keywords: Nanopowders, Phosphors, Luminescence.

CaAl2O4:Eu2+,Dy3+ is a member of the large family of alkaline earth aluminates doped with rare

earth impurities. These phosphors are energy storage materials that absorb ionizing radiation, UV and

visible light and gradually emit light during a long time after the excitation source is turned off. Currently,

most of the doped phosphors are prepared by solid-state reactions at high temperatures. In this work, we

present the behavior of thermally (TL) and optically stimulated luminescence (OSL) created by beta rays

in a novel CaAl2O4:Eu2+,Dy3+ prepared by combustion synthesis followed by annealing at high

temperature. The combustion synthesis involves a highly exothermic redox reaction between nitrates

(oxidizer) and an organic fuel (carbohydrazide, CH6ON4) to produce complex oxides. Due to the nature of

the reaction, these oxides are highly porous material composed of micro- and nanosized crystallites with

monoclinic and cubic structures. The TL and OSL properties of irradiated CaAl2O4:Eu2+,Dy3+ were

interpreted by the mechanism based on the transformation of Eu2+ and Dy3+ to Eu3+ and Dy2+ under

irradiation and their reverse transformation under thermal or infrared light stimulation. The Eu2+ ions are

the luminescent centers and the Dy2+ centers are the infrared sensitive traps responsible for the TL peaks

and OSL.

P-041


62

CONFORMAL COATING OF POWDERS BY THE ATOMIC LAYER METHOD

D. Domínguez1a, H. Tiznado1b, F. Muñoz1c, J. Romo-Herrera1d, O.E. Contreras1e and G. Soto1f.

1 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada, C.P 22860, Ensenada B.C. México

[email protected],[email protected],[email protected],


Keywords: Atomic layer deposition; powder; coatings.

Coating technologies have been extensively used to modify the physical and chemical properties

of materials. But with the development of nanotechnology, coating technology has extended their

applications into conformal coatings at the nanometer scale. Now, 3D shaped-surface morphologies can

be coated conformably with ultrathin layers. The resulting core-shell structures are being subject of great

interest, triggering the development of many approaches to produce them. ALD is a versatile technique

that can be used to coat and functionalize surfaces either with single or multiple components. The

foremost advantage of ALD is its ability to control the coating thickness down to the atomic level as a

function of number of ALD cycles. The aim of the present work is to demonstrate the feasibility of ALD

reactors in the synthesis of core-shell structures for research purposes. With very simple modifications

implemented on a typical ALD system and without going into the fluidized bed problematic, the resulting

setup can handle powders-like materials of any density and diverse morphological characteristics and at

the same time planar substrates like silicon wafers and glass slides. To show the capabilities of the ALD

setup, three powders with completely different characteristics were coated with Al2O3 or TiO2 with

excellent shell thickness control at the nano-level. Such illustrative cases correspond to carbon nanotubes

(CNTs), ZnO flower-like microarrays, and YCrO3 ferromagnetic particles. This work was financially

supported by CONACyT 83275, 82984 and DGAPA IN114209-3 and IN109612. The authors

acknowledge the technical assistance of M. Ruiz, A. Tiznado, N. Paredes, E. Medina, J. Díaz, F. Ruiz and

P. Pizá. We thank to A. Duran and M. Herrera for supplying some of the powder samples.

P-042

LUMINESCENT Y2O3:Eu3+ SYNTHESIZED BY HYDROTHERMAL ROUTE

Tzipatly Angélica Esquivel Castro1, a, Antonieta García Murillo1, b, Felipe de J. Carrillo Romo1, c, Jorge Alberto Torres Rodríguez1, d, Haggeo Desirena Enriquez2, e, Solange Ivette Rivera Manrique1, f

1 Instituto Politécnico Nacional – CIITEC Azcapotzalco, Cerrada de Cecati S/N, Col. Santa Catarina, Del. Azcapotzalco; C.P. 02250 México, D.F.

2 Universidad de Guanajuato - CIO León Gto., Loma del Bosque #115, Col. Lomas de Campestre, C.P. 37150 León Gto. México.


63

[email protected],[email protected],[email protected],[email protected], [email protected], [email protected]

Keywords: Y2O3:Eu3+, Phosphor, Hydrothermal, Powders, Luminescent.

The rapid development of new types of high-resolution devices such as cathode-ray tubes

(CRTs), electroluminescence devices (ELDs), plasma display panels (PDPs) and field emission displays

(FEDs) has created the need for optical phosphors with new or enhanced properties. In recent years, many

studies of oxide-based powders phosphors have been conducted because of the inherent problems

presented by sulfides, such as chemical instability and sensitivity to moisture; in addition, oxide-based

phosphors can be easily doped in order to obtain good luminescent properties as in the case of Y2O3:Eu3+

at 612 nm red emission produced by the 5D0 -> 7F2 transition of europium, is a useful red phosphor for

lighting and displaying applications. One form of this material is synthesized by hydrothermal technique

which makes it possible to prepare phase-pure products in a single step, from inexpensive and easily

accessible precursors, and can be performed at a relatively moderate temperature and pressure using a

simple autoclave. Also can have very small particles of the order of nanometers. This work present the

synthesis of luminescent glass ceramic powders described Y2O3: Eu3+ doping 5% of Eu3+, using the

hydrothermal method, with a temperature of 200 ° C, several experiments were performed by changing

the pH starting from pH 7 to pH 12, with a higher performance of the Y2O3: Eu3+ powder as pH increases.

The precursors used were yttrium oxide (Y2O3), nitric acid (HNO3), sodium hydroxide (NaOH),

europium nitrate Eu (NO3)3. Chemical and structural results carry out by FT- IR and XRD of Y2O3: Eu3+

ceramic powders luminescent powders were analyzed. Chemical analysis carry out by FT-IR on Y2O3:

Eu3+ powders obtained at pH=12 showed two infrared characteristic bands assigned to OH stretching and

deformation vibrations situated at around 3500 cm-1 and 1650 cm-1 respectively. Two main bands

occurring at 571 cm-1 and 471 cm-1 show the characteristic bands of Y-O. The X-Ray studies revealed

the cubic structure after a thermal treatment of 700 °C and 2h.

P-043

SYNTHESIS OF SiO2 AEROGELS UNDER SUPERCRITICAL CONDITIONS

Jorge Alberto Torres Rodríguez1, a, Antonieta García Murillo1, b, Felipe de J. Carrillo Romo1, c, Tzipatly Angélica Esquivel Castro1, d, Sebastián Díaz de la Torre1, e

1 Instituto Politécnico Nacional – CIITEC Azcapotzalco, Cerrada de Cecati S/N, Col. Santa Catarina, Del. Azcapotzalco; C.P. 02250 México, D.F.


Keywords: Aerogel, supercritical drying, insulator, sol – gel.


64

In recent years, silica aerogels have attracted great attention due to their unique properties and

potential applications in a wide variety of technology areas. Silica aerogels have nanostructured high

surface area, high porosity, low density, and excellent insulating properties. Aerogels are synthesized in

two steps, the first gel is obtained using the sol- gel method, in the second, the gel is dried, and we have

mainly focused our study in this second step. In order to perform the drying of silica gels, a supercritical

drying chamber had formed using a previously designed pattern. However, the effect of rheological

agents (also called surfactants) in the synthesis of the gel was studied. Specifically, this work, describe the

synthesis of SiO2 – F127 and SiO2 – PVP aerogels using sol - gel and subsequent supercritical drying at

low temperature using supercritical drying equipment designed and varying concentrations of surfactants.

The precursors used in the gel formation were tetramethylorthosilicate (TMOS), methanol (MeOH),

ammonium hydroxide as catalyst (NH4OH) and water in the molar ratio 1:7:0.7:2.7. Chemical, structural

and morphological results performed by FT-IR, XRD and SEM techniques of the obtained silica aerogels

were analyzed. The XRD results shows an amorphous structure of the SiO2 matrix, SEM micrographs

shows the change in particle size(≈5 – 45 nm) and the change in porosity with the amount of surfactant

used.

P-044

INFLUENCE OF SILVER/SILICA NANOPARTICLES ON STRUCTURAL PROPERTIES OF BBB MODEL LANGMUIR MONOLAYERS

Eva D. Ruiz1,a, Jaime Ibarra2,b, Mario Almada2,c,Josué Juárez2,dand Miguel A. Valdez2,e

1 Departamento de Física, Universidad de Sonora, Hermosillo, Sonora México.

2 Departamento de Física, Universidad de Sonora, Hermosillo, Sonora México.

[email protected],[email protected],

[email protected]

Keywords: Alzheimer, Blood-brain-barrier, nanoparticles, nanocomposites, Langmuir-Blodgett.

Alzheimer’s disease (AD) is a neurological disorder characterized by the formation of insoluble

plaques comprising fibrils of aggregated β-amyloid protein. The treatment of Alzheimer's disease and

many other brain-related disorders is limited because of the presence of the blood-brain barrier (BBB)

formed by brain endothelial capillary cells. The use of nanoparticles able to pass through the BBB and

interact with β-amyloid peptide is one of the strategies that have been proposed in order to avoid peptide

aggregation of toxic structures and discovering a new therapeutic approach for Alzheimer's disease by

photothermal activity. With the aim to have better comprehension about the physiological behavior

between nanoparticles and endothelial cell membrane, Langmuir monolayer of raw extract of bovine


65

brain phospholipids were using to studied the adsorption of Silver/Silica nanoparticles at the air–liquid

interface. Silver/Silica nanocomposites were synthesized and characterized by Zeta potential, DLS, IR,

and the effect of on the structural properties of monolayers model has been investigated analyzed area-

surface pressure isotherms, and AFM.

P-045

EFFECT OF FLOW RATIO N2/Ar ON STOICHIOMETRY AND THE HARDNESS OF TANTALUM NITRIDE COATINGS

K. Valdez1,a and W. De La Cruz2,b

1 Centro de Investigación Científica y de Educación Superior de Ensenada. Ensenada, B. C. México.

2 Centro de Nanociencias y Nanotecnología, CNyN-UNAM.Ensenada, B. C. México.


Keywords: Tantalum nitride, depth profiles and nanoindentation

TaNx thin films were synthesized by magnetron sputtering on silicon (111) substrates. We used a

tantalum target of high purity in the presence of N2 and Ar. The N2 flow was varied from 1 to 3 sccm and

Ar flow was kept at 10 sccm. The deposits were made under the following conditions: power=100 watts,

total pressure=8 mTorr, substrate temperature=500 °C and time of deposit=45 min. The physic-chemical

characterization was made with a Scanning Auger Microprobe (SAM) of PHI model 595. To determine

the hardness values were used a nanoindenter HysitronUbi 1, Inc with a Berkovich tip, applying the

method proposed by Oliver et al. and Korsunskyet al. The nanoindentation measurements reveal that the

maximum value of hardness was 38 GPa for the film deposited with N2 flow of 2 sccm (ratio N2/ Ar =0.

2) and stoichiometry TaN0.40. Acknowledgements: This work was partially supported by Dirección

General Asuntos del Personal Académico (DGAPA) projects IN107213 and IN103711. KV received a

scholarshipfrom Consejo Nacional de Ciencia y Tecnología (CONACyT), Mexico.

P-046

PULSED LASER DEPOSITION OF P-TYPE NIOX AND N-TYPE TIO2 HETEROJUNCTION THIN FILMS AND CURRENT-VOLTAGE MEASURAMENT WITH UV IRRADIATION.

A.Fajardo1,2a , Gustavo Hirata1, W. de la Cruz1, G. Guzman1, and J. McKittrick3

1 Centro de Nanociencias y Nanotecnología-UNAM, Km. 107 Carretera Tijuana-Ensenada, Apdo. Postal, 356, CP. 22800, Ensenada, B.C. México,

2 Posgrado en Ciencias e Ingeniería-UNAM, Km. 107 Carretera Tijuana-Ensenada, Apdo. Postal, 356, CP. 22800, Ensenada, B.C. México


66

3 Mechanical and Aerospace Engineering, University of California, -San Diego, La Jolla, CA 92093-0411.

[email protected]

Keywords: Heterojunction, thin film, semiconductor oxide.

Nickel oxide (NiO) has been used in photoelectrochromic devices due to its p-type intrinsic

behavior. Titanium oxide (TiO2) is an n-type semiconductor with excellent photocatalytic properties. In

this work, Ni and Ti films were deposited by the PLD technique at room temperature and oxidized at

550ºC in air for 2 hours to form NiO and TiO2, respectively. The third harmonic (λ= 355 nm) of a

YAG:Nd pulsed laser operated at an energy fluence of 3 J/cm2 and 10 Hz repetition rate was used for the

laser ablation experiments. Microstructural development and chemical composition of the films were

analyzed by SEM, XRD, AES/XPS and XRD techniques. Hall Effect and Van der Pauw measurements

confirmed p- and n-type behavior of NiO and TiO2 films, respectively. Heterojunctions have been

fabricated by deposition of p-type NiO on n-type TiO2 on ITO coated glass substrates. The relationship

between electrical and photocatalytic properties of NiO and TiO2 thin films irradiated with UV will be

discussed. Support from DGAPA-UNAM (Grant No. IN114010) and CONACYT (Grant No. 100555)

and technical assistance by E. Aparicio, D. Dominguez and I. Gradilla are acknowledged.

P-047

PULSER LASER DEPOSITION AND STRUCTURAL CHARACTERIZATION OF GAN / TIO2

HETEROJUNCTION THIN FILMS.

A.Fajardo1,2a, Gustavo Hirata1, P.Sengar1,3, , A.Jain1,3

1 Centro de Nanociencias y Nanotecnología-UNAM, Km. 107 Carretera Tijuana-Ensenada,Apdo. Postal, 356, CP. 22800, Ensenada, B.C. México,

2 Posgrado en Ciencias e Ingeniería-UNAM, Km. 107 Carretera Tijuana-Ensenada,Apdo. Postal, 356, CP. 22800, Ensenada, B.C. México

3 Posgrado en física de materiales del centro de investigación científica y de educación superior de ensenada

[email protected]

Keywords: Heterojunction , thin film, semiconductor oxide.

Pulsed-laser deposition is now a largely used growth method to prepare functional and

multifunctional oxide films for application in microelectronics, spintronics, optics, materials for energy.

The functional properties of such oxide films are strongly depending on the crystalline structure, and on

the chemical composition through the local environment of cationic species surrounded by oxygen. Rutile


67

TiO2 (100) thin films have been prepared on GaN by pulsed laser deposition (PLD) method, using

Titanium and GaN targets. The annealing effects in the range of 400-600 ˚C in a tubular furnace are

studied. The TiO2 and GaN thin films were characterized by X-ray diffraction (XRD), atomic force

microscopy (AFM) and scanning electron microscopy (SEM).The technical assistance by E. Aparicio, D.

Dominguez and I. Gradilla are acknowledged.

PP-048

SYNTHESIS OF LUMINESCENT NANOPARTICLES COATED WITH BIOCOMPATIBLE MATERIALS

Hirata Flores G. A 1,a, Reyes García A. A.2,b

1 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, Baja california, MX CP 22860, México

2 Instituto Tecnológico de Oaxaca, Oaxaca, Oax. MX CP 68030, México


Keywords: (SiO)2 shell thicnkness, luminescence, core/shell, phosphor.

In the present investigation, Luminescent nanoparticles coated with biocompatible materials were

developed, in order to attach a drug, which will be released in the brain to attack cancer in areas of

difficult access. New advances in nanotechnology and biotechnology allow us to develop new non-

invasive methods for detection and treatment of diseases, which are safer and less risky than conventional

surgery. Oxide nanoparticles yttrium aluminum doped with praseodymium to 1% (YAG:Pr) was

synthesized by the method of combustion synthesis, which were coated with different biocompatible

materials (polyethylene glycol) PEG (polyvinylpyrrolidone) PVP and silica classified three categories

labeled case A, B and C. Ten samples which were obtained were characterized by: luminescence,

quantum efficiency, XRD and SEM. In samples characterized by luminescence by UV / VIS

characteristic profile was obtained YAG: Pr which showed an intense band at 318 nm emission when

excited with a wavelength of 292 nm; of these samples white and MA2 and MA3 cases were the most

efficient. The characterization by XRD, The characteristic diffraction pattern is obtained YAG:Pr

corresponding to the cubic phase material. Characterization by EDS demonstrated the successful

incorporation of the desired results without the presence of other elements. In the SEM micrographs at

1000 X scales of different sizes were observed for 5, 10, 15 and 20 micrometers long and a thickness of

0.2-0.6 micrometers. The micrograph obtained with the TEM could be seen coated with polyethylene

glycol, where a thin film of polymer attached to a nanoparticle of about 120 nm by 300 nm oval

appearance shows. Which indicates that the nanoparticle can be biocompatible. The above results indicate


68

that the material obtained is of high quality and can be used as a bio-marker, drug carrier and in the

diagnosis of certain diseases.

P-049

INTERACTION OF MAGNETITE@PLGA NANOPARTICLE WITH CELL MEMBRANE MODEL AT THE AIR-WATER INTERFACE

Baltazar H. Leal-Martínez1,a, Jaime M. Ibarra-Hurtado1 , Julio Melendres1, Josué Juárez2, Miguel A. Valdez2,b

1 Posgrado en Nanotecnología, Universidad de Sonora, México

2 Departamento de Física, Universidad de Sonora, México


Keywords: Polylactic-co-glycolic acid (PLGA), Magnetite (FeO4), Phospholipids, biodegradable,

biocompatibility, Langmuir trough, Langmuir-Blodgett monolayer.

One of the most important requirements for the use of nanoparticles and other synthetic systems

as drug delivery systems for human therapy is their biodegradability and biocompatibility. In past two

decades poly lactic-co-glycolic acid (PLGA) has been among the most attractive polymeric candidates

used to fabricate devices for drug delivery and tissue engineering applications. PLGA is biocompatible

and biodegradable, exhibits a wide range of erosion times, has tunable mechanical properties and most

importantly, is a FDA approved polymer. Besides synthesis of magnetite (Fe3O4) nanoparticles has long

been of great interest because of their immense technological applications especially in the form of

ferrofluids. Nanoparticles with super-paramagnetic properties have great potential to achieve such

desirable properties. We synthesized and characterized magnetite nanoparticles coated with amphiphilic

block copolymer of PLGA by Dynamic Light Scattering (DLS) and Zeta Potential. Also we studied the

interaction between magnetite@PLGA nanoparticles in a cellular membrane model (raw extract of bovine

brain phospholipids) in an air-water interphase using Langmuir-Blodgett trough. We obtain the isotherm

-A from the extract of phospholipids. Langmuir-Blodgett monolayers were extracted as a function of

surface pressure and magnetite@PLGA nanoparticles concentration, and characterized by Atomic Force

Microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR).

P-050

SYNTHESIS OF MULTIFUNCTIONAL NANOPLATFORM FORMED BY MAGNETITE, PLGA AND CHITOSAN WITH POTENTIAL THERANOSTIC PROPERTIES.


69

Ibarra Hurtado JM1,a, Almada Mario1,b, Julio Melendres1,c, Eva D. Ruiz1,d, Baltazar H. Leal-Martinez1,e, Juárez Josue1,f , Valdés Miguel A.1,g

1 Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, México.


Keywords: PLGA, nanoplatform, theranostic, magnetite, paclitaxel.

Polymeric nanoparticles made from biocompatible and biodegradable block copolymers as poly

(lactic acid-co-glycolic acid) (PLGA) are commonly used for the controlled release of drugs or to

encapsulate contrast agents that permit the use of these nanosystems as a diagnostic tool, usually

performing only one function at a time. Based on this, our work consists in the preparation of a

multifunctional nanoplatform with theranostic properties. The multifunctional nanoplatform is constituted

by a core of superparamagnetic particles of magnetite embedded in a polymeric matrix of PLGA, which

also encapsulate the active substance (paclitaxel); finally the polymer matrix is coated with the other

biocompatible polymer, chitosan. After the synthesis of the nanoplatform, this was characterized in terms

of size, shape and surface charge, using techniques such as Dynamic Light Scattering (DLS), Atomic

Force Microscopy (AFM), Transmission Electron Microscopy (TEM) and Zeta Potential. Additionally,

Infrared Spectroscopy (FTIR) was performed to monitor the different stages of ensemble of the different

materials building the nanoplatform. The analysis of loading efficiency and release kinetics of the drug

was performed using UV Visible spectroscopy. Finally, the prospect for our work is to evaluate the in

vitro cytotoxicity of multifunctional nanoplatform with specific tumor cell lines.

P-051

SYNTHESIS AND CHARACTERIZATION OF COPPER TELLURIDE (CuTe) BY ION EXCHANGE

O. Arellano-Tanori1,2,3, R. Godoy-Rosas1,4,a , H.A.Pineda-Leon1,4,b, E. Fernadez-Diaz1,2,c, E. Chavez-Mendiola1,2, T. Mendivil-Reynoso1,5,6 ,R.Ochoa-Landin6, S.J. Castillo1

1 Departamento de investigación en Física, Universidad de Sonora, Apdo. Postal 5-088 CP 83000, Hermosillo, Sonora, México.

2 Instituto Tecnologico de Hermosillo, Av. Tecnologico s/n Col. Sahuaro, CP 83170, Hermosillo, Sonora, Mexico.

3 Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Sonora N., Blvd. Enrique Mazón Lopez No.965, CP 8300, Hermosillo, Son, Mexico.

4 Departamento de Matemáticas, Universidad de Sonora, Luis Donaldo Colosio y Rosales s/n CP 83000, Hermosillo, Sonora, México.


70

5 Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial. CP 31109 Chihuahua, Chih, México.

6 Departamento de Física, Universidad de Sonora, Apdo. Postal 1626, CP 83000, Hermosillo, Sonora, México.


Keywords: copper telluride, photometry XPS, FTIR, X-ray (EDS), bandgap, crystalline orthorhombic,

rongalite, tellurium ions.

The method used for the synthesis of copper telluride is mainly based on chemical reaction

precursors containing tellurium and copper. Copper nitrate was used to produce copper, for tellurium

rongalite tellurium ions. The absorption spectrum for the sample of copper telluride displays

corresponding values for direct bandgap 3.01 eV and 2.91 eV in-direct bandgap at room temperature.

FTIR studies were conducted corresponding to spectrum characteristic absorption peaks for copper

telluride 530 cm-1 which identifies copper nanoparticles. The Raman study sample exhibits bands at 411,

438 and 471 cm-1 in tellurate hydrate copper (CuTeO3 2H2O). XPS copper telluride, shows the peaks

for Te 3d3 and Te 3d5 corresponding to the value of binding energy of 575.5 eV, which identifies

tellurium ions; Te 3d region shows that the valence of Te is -2, while the Cu 3p valence region show for

copper 1. In the sample of copper telluride TEM, one can observe an aspect of a well-defined nano-

caterpillar. Electron diffraction shows interplanar distance 3.514 Å and d = 3.566 Å very similar and

elucidated the crystal structure, these distances are typical for a crystalline compound CuTe orthorhombic

(JCPDS # 22-0252), the study is achieved by magnifying the region until the 10 nm (400 000 extensions).

The study of energy dispersive spectroscopy X-ray (EDS) quantifies the elements in weight percent,

74.92% wt copper and 8.56 wt% for tellurium.

P-052

PREPARATION OF NANO-STRUCTURED POWDER OF COBALT TELLURIDE (CoTe2) BY ION EXCHANGE IN CHEMICAL REACTIONS

O. Arellano-Tanori1,2,3,a, H.A.Pineda-Leon1,4,c, E. Fernadez-Diaz1,2,d, E. Chavez-Mendiola1,2,e, R. Godoy-Rosas1,4,f, T. Mendivil-Reynoso1,5,b, R.Ochoa-Landin6,g,S.J. Castillo1,h




71

3 Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Sonora N., Blvd. Enrique Mazón Lopez No.965, CP 8300, Hermosillo, Son, Mex.




[email protected],[email protected],[email protected],[email protected] [email protected],[email protected],[email protected],hsemiconduct

[email protected]

Keywords: Nanoparticles, cobalt telluride, characterizations, ion Exchange

By using Cobalt Chloride and Tellurium ions in rongalite as precursors in the chemical reactions

Cobalt telluride was obtained in nano structured powder and characterized, obtaining this results: UV -Vis

direct and indirect bandgap 1.7 eV and 2.32 respectively. IR The sample was mixed with KBr pellets for

the reading of the spectrum, it can be seen that the absorption peaks at FTIR for cobalt telluride shows

absorption peaks at 3446 and 1600 cm–1 and at 524 cm - 1 corresponds to the vibrations of Co-O bonds,

the existence of this peak is ground for determining formation of cobalt telluride nanoparticles. Cobalt

telluride Raman spectrum shows frequencies that coincide with those in references listed. XPS spectrum

for cobalt telluride compound includes two binding energies corresponding to tellurium Te 3d5/2 and Te

3d3/2, and cobalt 2 p/2 and 2 p1/2 for features shown. TEM the interplanar distance obtained were d =

3.28 Å and d = 1.97 Å. These distances are characteristic of a corresponding orthorhombic structure

CoTe2 whose crystallographic planes are the [001] and [220] (JCPDS # 65-2572)

P-053

SYNTHESIS AND CHARACTERIZATION OF STRONTIUM SELENIDE (SrSe) CHEMICAL REACTION BY USING ION NITRATE COPPER AND SELENIUM IN RONGALITE

O. Arellano-Tanori1,2,3,a, T. Mendivil-Reynoso1,4,6,b, H.A.Pineda-Leon1,4,c,E. Fernadez-Diaz1,2,d, E. Chavez-Mendiola1,2,e, R. Godoy-Rosas1,4,f, R.Ochoa-Landin6,g,S.J. Castillo1,h


2 Instituto Tecnológico de Hermosillo, Av. Tecnológico s/n Col. Sahuaro, CP 83170, Hermosillo, Sonora, México.

3 Instituto Tecnológico y de Estudios Superiores de Monterrey, Campus Sonora Norte, Blvd. Enrique Mazón López No.965, CP 8300, Hermosillo, Sonora, México.


72

4 Departamento de Matemáticas, Universidad de Sonora, Luis Donaldo Colosio y Rosales S/N CP 83000, Hermosillo, Sonora, México.

5 Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial. CP 31109 Chihuahua, Chih. México.

6 Departamento de Física, Universidad de Sonora, Apdo. Postal 1626 CP 83000, Hermosillo, Sonora, México.

[email protected], [email protected], [email protected], [email protected] [email protected],[email protected],[email protected],hsemiconduct

[email protected]

Keywords: Strontium selenide, rongalite, semiconductor bandgap, optical absorption

SrSe is obtained using a chemical reaction by ion-exchange method, which are used with

strontium and selenium precursors. Characterization of optical absorption in this work is similar to that

obtained in a previously reported mathematical model, the direct band gap that 2.9 was found both eV and

the indirect band gap that was 4.5 eV. The FTIR spectroscopy which shows this research for the selenuro

of strontium, coincides with data previously reported, which validates the obtaining of the SrSe, in the

infrared spectrum, appear the same for bands at 3446 / 1600 cm-1 for the strontium selenide, and these

correspond to the O-H vibration and H -O - H, bending vibration respectively.

To use RAMAN spectroscopy to analyze SrSe, frequencies that characterize it, we identified was

observed the peak corresponding to 192 cm-1, which is the SrSe2. Was also performed studies of TEM

sample selenuro of strontium with the purpose of knowing its morphology, there are no defined

arrangements, particles agglomerated to obtaining a single distance interplanar for this compound, which

it can be concluded that it corresponds to a cubic array, the distance interplanar of this compound is d =

3.27 A, which corresponds to crystallographic plane [200] JCPDS # 10-0182).

P-054

SYNTHESIS AND CHARACTERIZATION OF STRONTIUM TELLURIDE (SrTe) BY CHEMICAL BATH, AND USING STRONTIUM CHLORIDE ION IN RONGALITE TELLURIUM.

O. Arellano-Tanori1,2,3, H.A.Pineda-Leon1,4,b , E. Fernadez-Diaz1,2,c, E. Chavez-Mendiola1,2, T. Mendivil-Reynoso1,5,6 , R. Godoy-Rosas1,4,a , R.Ochoa-Landin6, S.J. Castillo1




73






Keywords: Strontium Telluraide, rongalite, semiconductors, bandgap, optical absorption

This work is a method of obtaining the strontium Telluride, this work reports few related

investigations in which the strontium Telluride was synthesized and they are part of this investigation,

since them, validate the results obtained in this document. New method of synthesis, which are obtained

satisfactory results that are similar to those reported in other research is proposed. The method used for

the synthesis of strontium Telluride is bath chemical based primarily on precursors containing tellurium

and strontium .Shows the characterization of optical absorption where it was determined indirect bandgap

of 1 eV and 3.3 eV direct bandgap. Subsequently be characterized the tellurium of strontium with the

FTIR absorption peaks were observed approximately at 3446 and 1600 cm - 1 to metallic tellurium,

which correspond to the o-h vibration and vibration of bending h-o - H, respectively, this is due to the

absorption of H2O in these sample. The following characterization was RAMAN spectroscopy, yielding

approximately 158 cm-1, which is attributed to the binaries of tellurium compounds of strontium.

P-055

ADSORPTION OF MAGNETITE@PLGA NANOPARTICLES IN A CELLULAR MODEL

Julio Melendres1, a, Jaime M. Ibarra-Hurtado1, Baltazar H. Leal-Martínez1, Josué Juárez2, Miguel A. Valdez2, b

1 Posgrado en Nanotecnología, Universidad de Sonora, México

2 Departamento de Física, Universidad de Sonora, México


Keywords: Membrane model, Nanoparticles, Magnetite, PLGA, Viscoelastic properties

Nowadays, the major challenges for nanotechnology applied into the biomedical area is the

development of devices capable to be used in the diagnosis and therapy of a given diseases. In this

regards, due to its biodegradability and biocompatibility nanoparticles of poly lactic-co-glycolic acid


74

(PLGA) have great potential. In the development of theragnostic nanoplatform, however; to achieve both

therapeutic action and diagnosis role, nanoparticles have to overcome several biological barriers,

especially with the cell membrane. Herein we studied the interaction of magnetic core PLGA

(magnetite@PLGA), nanoplatform with a cellular membrane model consisting of raw bovine brain

phospholipids at the chloroform-water interface. The adsorption process of magnetite@PLGA at the

cellular membrane was followed by drop tensiometer and the mechanical properties of interface were

determined. Additionally, for reinforcing the data, characterization tests with Atomic Force Microscopy

(AFM) and Fourier Transform Infrared Spectroscopy (FTIR), Dynamic light scattering (DLS) and Zeta

potential were done.

P-056

ENERGY BANDS OF THE 1H-MOS2 OVER OXIDE OF GRAPHENE REDUCED

Juan Estrada-Cruz1,a, Sergio Fuentes-Moyado2,b and Donald Galvan-Martinez2,c

1 Centro de Investigación y de Educación Superior de Ensenada, Baja California, México

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Baja California, México


Keywords: Density functional, MoS2, graphene, electronic properties, electrocatalyst.

The MoS2/RGO is a hybrid material exhibiting an extraordinary performance in lithium ion

battery (LIB) and the hydrogen evolution reaction (HER). This material is able to replace platinum in the

new generation of nanostructured electrocatalyst. This extraordinary electrocatalyst used electronic

properties of reduced graphene oxide (RGO) and the active sites on the edges of MoS2. The behavior of

this hybrid electrocatalyst suggests a synergy between the two systems. In this work we present the

adsorption RGO on a monolayer MoS2 using the Density Functional Theory (DFT) and synthesis of

monolayer MoS2/RGO by solvothermal method. It was found the binding energy of adsorption and the

distance between the layers is 3.7 meV and 3.33 Å, respectively, showing a weak interaction between the

systems. We found stable Dirac cones displaced downward 0.3 eV of the Fermi level indicating the

transfer of electrons from MoS2 to the RGO. This transfer of electrons may be responsible for the synergy

between the systems. The images from (HR-TEM) and the diffraction pattern show the MoS2 as

monolayers added to the high dispersion of the MoS2 sheets formed on RGO as well as oxygen residue in

the samples.

P-057


75

LUMINESCENT MAGNETIC NANOPARTICLES FOR DETECTION AND TREATMENT OF CANCER BY THERMAL ABLATION

N. Izaguirre1,a, G.A. Hirata2,b

1 Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana No. 3918, Zona Playitas, C. P. 22860, Ensenada, B. C., México.

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km. 107 Carretera Tijuana-Ensenada, C. P. 22860, Ensenada, B. C., México.

[email protected] and [email protected], [email protected]

Keywords: magnetite, luminescent, multifunctional nanoparticles

In recent years has increased the interest for developing multifunctional materials which can be

used for diagnosis and therapies for major diseases such as cancer. The purpose of this work is the

synthesis and characterization of luminescent/magnetic nanoparticles (LMNPs) made of magnetite

(Fe3O4) and their simultaneous combination with europium doped lanthanum oxide (La2O3:Eu), terbium

doped lanthanum oxide (La2O3:Tb) or thulium doped lanthanum oxide (La2O3:Tm) for possible

applications as contrast and thermal ablation agents in cancer treatment.

The method used to obtain the LMNPs is spray pyrolysis due it allows the synthesis of

nanoparticles with narrow size distribution, adjustable size, high crystallinity and good stoichiometry.

Luminescent nanoparticles were prepared with different concentration of dopant material and were post

annealed at different temperatures in order to find the best luminescent response. Once obtained the

luminescent materials with the highest luminescence, the synthesis of luminescent/magnetic materials was

followed. This second step was done for different concentration of luminescent and magnetic

nanomaterials in order to obtain the best multifunctional properties material. The determination of the

best material was made by characterizing the nanoparticles with different techniques such as

spectrofluorometer, X-ray diffractometer (XRD), scanning electronic microscopy (SEM), transmission

electronic microscopy (TEM), SQUID magnetometer and magnetic induction device. Partial support from

CONACyT (Grant 100555) and DGAPA-UNAM (Grant IN-109913) and technical work provided by E.

Aparicio, F. Ruíz and I. Gradilla is gratefully acknowledged.

P-058

AU SEEDS STABILITY

L. Avalos1,a, O.E. Contreras2,b, J.M. Romo-Herrera2,c E.I. Chaikina1,d, E.R. Méndez1,e

1 Depto. Optica, Div. Física Aplicada CICESE, Ensenada B.C., México



76


Keywords: nanoparticles, gold, seeds, colloid chemistry.

Gold metal nanoparticles (NPs) have attracted great attention due to their ability to support

localized surface plasmon resonances (LSPRs). These Plasmon modes can be tailored by modifying the

size and shape of the NPs. Such optical properties suggest them for sensing, imagining, diagnosis and

biomedical therapeutic applications among others.Colloidal techniques have become one of the most

useful techniques to synthesize such Au NPs, with the ability to obtain a high degree of shape control by

means of non-sophisticated equipment. Specifically, the seed-mediated approach gives access into a wide

range of morphology when adjusting the synthesis parameters. There, the basic idea is to use a strong

reducing agent to prepare Au0 seeds (2-5nm sphere NPs) from gold salts in water as the first step; to

subsequently use a weak reducing agent to reduce more gold salt onto the seed NPs as the a second step.

In the solution-phase synthesis, the shape displayed by the NPs is strongly dependent on the initial seeds.

Here we follow a common colloidal method to obtain the Au seeds (3-4nm sphere NPs) using NaBH4 as

the strong reducing agent. Once obtained, we have monitored the NPs stability when protected by

different capping agents. Besides, we have been able to finely tune the seeds size increasing their

diameter 1nm by 1nm; analyzing the role of different capping agents into the diameter increment control.

Finally, we explore the aging effect of the seeds for obtaining anisotropic NPs. The samples

characterization has been performed by UV-Vis spectroscopy and TEM. Acknowledgements: We thank J.

Mendoza, F. Ruiz, E. Flores and H.F. Alonso for technical assistance.

P-059

PEGYLATED LIPOSOMES FOR ENCAPSULATION OF ANTI-GLAUCOMA DRUG FOR THE SUSTAINED TREATMENT OF INTRAOCULAR PRESSURE

López Millán A1,a, Jiménez Róman J2, Gutiérrez Valenzuela C1, Hidalgo Martínez R. A3,b, López Esparza R4, López Millán A.

1 Posgrado en Nanotecnología, Depto. De Física, Universidad de Sonora, México

2 Asociación Para Evitar la Ceguera en México (APEC) México, D.F.

3 Instituto Mexicano del Seguro Social, Sonora, México.

4 Depto. De Física, Universidad de Sonora, México


Keywords: Liposomes, drug, glaucoma.


77

Topical medication remains the first line treatment for glaucoma, however, the sustained release

of drugs topically is difficult to achieve. Most drugs have poor penetration of the cornea and are rapidly

degraded. The administration of drugs in a sustained manner by the use of structures, such as liposomes,

can provide the patient with an optimal dose of the drug, with minimal local toxicity and avoid problems

such as allergies due to daily drug administration. We have obtained nanoliposomes of

phosphatidylcholine (PC) with poly (ethylene glycol) (PEG) and Travoprost (drug) by rehydration

technique followed by extrusion, for the treatment of glaucoma. Using Optical Microscopy of Differential

Interference Contrast (DIC), Dynamic Light Scattering (DLS), Zeta Potential, Transmission Electron

Microscopy (TEM) and liquid chromatography (HPLC), we have characterized the morphology, size,

surface charge and drug encapsulation efficiency in pegylated liposomes.The technique of obtaining the

liposomes allows controlling their size that is versatile with respect to the initiation and composition. We

found that the incorporation of PEG-Travoprost stabilizes the liposome system allowing its size and shape

remain without significant changes over a period of 4 weeks and the percentage of Travoprost obtained

incorporated pegylated liposome membrane was significantly higher. The molar ratio was 0.1 and the

more stable is proposed for further study in animal models.

P-060

GREEN SYNTHESIS OF GOLD NANOPARTICLES USING RUMEX HYMENOSEPALUS

Ramón A. Iñiguez Palomares1,a, Ericka Rodríguez León2,b, Rosa Elena Navarro3,c, Obed Lugo3,d, Ronaldo Herrera Urbina2,e, Judith Tánori3,f, Amir Maldonado1,g

1 Departamento de Física, Universidad de Sonora, Hermosillo, Sonora, 83000, México

2 Departmento de Ingeniería Química y Metalurgia, Universidad de Sonora, Hermosillo, Sonora, 83000, México

3 Departmento de Polímeros y Materiales, Universidad de Sonora, Hermosillo, Sonora, 83000,

México

[email protected], [email protected], [email protected],


Keywords: gold nanoparticles, bioreductors agents, Rumex hymenosepalus.

The synthesis of gold nanoparticles has generated huge interest by its optical properties and its

uses like medicaments. For biomedical applications is required a synthesis route that uses non toxics

compounds and biocompatible, by this reason many research groups have developed methods that employ

bioreductors agents. In this work we use an extract of the plant Rumex hymenosepalus (this plant is

located in Sonora, México and the southwest of USA) for to synthesize of gold nanoparticles with the use


78

an aqueous solution of Gold (III) chloride to this suspension we aggregate different concentrations of

sodium chloride in the range of 0 to 1M. The Rumex hymenosepalus plant contains catequins and stilbens

this polyphenols act like bioreductors and also like stabilizers. The results of the uv-vis spectroscopy and

the transmission electronic microscopy indicate that the shape and size of the nanoparticles obtained

changed with the sodium chloride concentration. The size of the gold nanoparticles are 36.5±10.3nm for

the low concentration and 76.8±15.5nm for the high concentration of sodium chloride. The shape

included hexagons, triangles, spheres and non-regular geometrical forms. The High resolution TEM

(HRTEM) show that fcc crystal structure is present in these nanoparticles.

P-061

DEVELOPMENT OF TRIMETALLIC NiMoW CATALYSTS SUPPORTED ON SBA-16 MODIFIED WITH TITANIUM BY DIRECT SYNTHESIS

O. Alonso-Pérez1,a, R. Huirache-Acuña1,b G. Alonso-Nuñez2,c, B. Pawelec3,d ,J.L.G. Fierro3,e

1 Facultad de Ingeniería Química, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Michoacán, México.

2 Centro de Nanociencias y Nanotecnología, UNAM, Ensenada, Baja California, México.

3 Instituto de Catálisis y Petroleoquímica, CSIC, Madrid, España.


Keywords: SBA-16, direct synthesis method, NiMoW catalysts, hydrodesulfurization.

In the present work, mesoporous silica SBA-16 was modified with titanium by direct synthesis

method. From these supports NiMoW catalysts were developed in order to achieve higher performance

for removal of sulfur in the reaction of hydrodesulfurization (HDS) of dibenzothiophene (DBT). To

determine the effects of the incorporation of titanium in the structure of SBA-16, its interaction with the

active phases and the dispersion on the catalyst surface, the samples were characterized by a variety of

techniques as N2 adsorption-desorption isotherms, XRD, TPR, TPD-NH3, DRS UV-vis and HRTEM.

P-062

SYNTHESIS OF BIODEGRADABLE PH-RESPONSIVE STAR BLOCK COPOLYMERS VIA RAFT AND ROP

Huerta-Guerra Verónica1,a , , Cortez-Lemus, Norma A.*1,b Licea-Claverie, Ángel1,c


[email protected] [email protected]


79

Keywords: Star polymers, pH-responsive polymers, copolymer, biodegradable, RAFT, ROP, nano-

aggregates.

Stars polymers are fascinating materials with unique properties when compared to linear

polymers. For example, they have a hydrodynamic size much smaller and higher degree of

functionalization. Moreover, star polymers have attracted also increasing interest in life sciences. They

can serve as biomedical devices such as DNA delivery vehicles, they can also be used as unimolecular

containers and can be seen as well-defined nanoparticles for applications in nanomedicine. Poly (2-

dimethylaminoethyl methacrylate) PDMAEM is an amphiphilic molecule, a weak polybase with a pKa of

about 8.0 and therefore a pH responsive polymer. Above its pKa, PDMAEM homopolymer is

hydrophobic since its tertiary amine groups are deprotonated. Below its pKa, PDMAEM becomes a

cationic hydrophilic polymer, since its tertiary amine groups are protonated. Meanwhile, PDMAEM has

numerous potential uses which include its use as delivery material for plasmid DNA drug delivery in

general and many other applications. Recently, it has been reported the synthesis of polymeric structures,

such as star block copolymers, by reversible addition-fragmentation chain transfer (RAFT)

polymerization. Also, the ring opening polymerization (ROP), is an excellent method used for the

incorporation of biocompatible and biodegradable polymeric chains. This work reports the synthesis of

pH-sensitive star block copolymers via ROP and RAFT on a consecutive manner. Firstly, a

trithiocarbonate chain transfer agent (CTA) functionalized with carboxyl groups was synthesized.

Secondly, ε-caprolactone was polymerized by ROP. Thirdly, the macro-CTA was synthesized coupling

the poly(ε-caprolactone) with the CTA by an esterification reaction. Finally, the multifunctional macro-

CTA was used for the polymerization of DMAEM via RAFT polymerization. The resulting star polymers

were characterized by RMN, FT-IR, GPC and DLS. Also, in aqueous solution, the star-type copolymers

PCL-b-PDMAEM prepared form nano-aggregates with PCL core (hydrophobic block) and PNVCL shell

(hydrophilic block). These nano-aggregates were studied by DLS

P-063

ION-MEDIATED BACTERICIDAL EFFECT OF SILVER NANOMATERIALS

Meza-Villezcas A.1, Jaime-Acuña, O.2, Raymond, O.2, Martynyuk, O.2, Bogdanchikova, N.2, Huerta-Saquero, A.2*

1 Facultad de Ciencias, UABC, Ensenada B.C.

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México.

*[email protected]

Keywords: Silver nanoparticles, silver/zeolite composites, bactericidal effect, toxicity.


80

Silver nanoparticles have good antimicrobial efficacy against bacteria, viruses and other

eukaryotic micro-organisms. Nowadays, silver colloids and silver nanoparticles have been used in

medicine for burn treatment, dental materials, coating stainless steel materials, textile fabrics, water

treatment, and sunscreen lotions, among others. Silver nanoparticles have low toxicity to human cells,

high thermal stability and low volatility.Controversy exists regarding the possible mechanism of action of

silver nanoparticles on microorganisms. In particular, if the bactericidal effect of silver nanoparticles is

due to direct contact of the nanomaterial with bacteria, or by the release of ions which alter the

membrane, and cause cell death, or by a combination of effects. In this work we show that the release of

silver ions from colloidal silver or silver/mordenite-based nanostructured composites is sufficient to exert

a bactericidal effect, without any contact between the silver nanoparticles and bacteria. Different tests as

ICP-AES, UV-Vis spectroscopy and TEM, support our results. Acknowledgments: This work was

partially supported by CONACYT (Grant 127633) and DGAPA-UNAM (Grant IN113312).The authors

thank to M. Vega and F. Ruiz for technical assistance.

P-064

SYNTHESIS AND CHARACTERIZATION OF Co-Ni LDHs NANOSHEETS AS ELECTROCATALYST FOR WATER OXIDATION

Ricardo Valdez 1, a, Douglas B. Grotjahn 2, b, J. M. Quintana 3, c, Amelia Olivas 4, d

1 Posgrado en Ciencia e Ingeniería de Materiales CNyN-UNAM, , Km. 107 Carr. Tij-Ens, 22860, Ensenada, B.C. Mexico.

2 San Diego State University, Department of Chemistry, 5500 Campanile Drive, San Diego, California 92182, United States.

3 Facultad de Ciencias Químicas e Ingeniería., UABC. Calz. Tecnológico No. 14418, Otay, U. Universitaria, 22390 Tijuana, Mexico

4 Centro de Nanociencias y Nanotecnología, UNAM, Km. 107 Carr. Tij-Ens, 22860, Ensenada, B.C. Mexico.


Keywords: LDHs; oxygen evolving; water oxidation; nanosheets; electrocatalyst

A very elegant possibility exists to get fuels by splitting water into oxygen and hydrogen

involving sunlight. To split water it is necessary to produce active, stable and reusable catalysts for water

oxidation reaction (WOR) and others for hydrogen evolution reaction (HER). Since the synthesis of a

catalyst for water oxidation is the masterpiece in the scheme to produce clean energy from water, here we

report the synthesis of nanosheets based on Co–Ni LDHs with well-defined morphology, where the


81

interlayers anions are (CO3)2−, Cl−, and H2O to balance the charge of the compound. The catalyst was

characterized by X-ray Diffraction (XRD), Transmission Electronic Microscopy (TEM) and Inductively

Coupled Plasma–Atomic Emission Spectrocopy (ICP–AES). The electrocatalytic measurements show

that oxygen is produced under mild conditions: pH = 7, at room temperature and 1 atm.

P-065

SYNTHESIS AND ELECTROCHEMICAL CHARACTERIZATION OF PD WITH GEOMETRY DEFINED TYPE CUBE

Velázquez Arjona, W. 1,a, Arriaga Hurtado, L. 2,b and Huerta Pérez, C.3,c

1 Centro de Investigación y Desarrollo Tecnológico en Electroquímica CIDETEQ S.C., Pedro Escobedo, Querétaro, México

2 Centro de Investigación y Desarrollo Tecnológico en Electroquímica CIDETEQ S.C., Pedro Escobedo, Querétaro, México


a [email protected], b [email protected], c [email protected]

Keywords: Nanoparticles Pd with cubic geometry, synthesis, cube

By chemical synthesis were prepared nanoparticles of Pd with type cube geometry, which were

characterized by cyclic voltammetry in acid medium, HR-TEM and EDS elemental analysis.


82

2ND POSTER SESSION

P-066

ELABORATION OF CADMIUM TELLURIDE THIN FILMS BY MEAN OF PULSED LASER DEPOSITION

O.M. Rodríguez-Sánchez1,2,a, L. Morales-Peral1,2,b, M.A. Santana-Rojas1,3,c, M. A. Quiroga-de la Torre1,3,d, S. J Castillo1



3 Instituto Tecnológico de Hermosillo, Av. Tecnológico S/N Col. El Sahuaro, CP 83170, Hermosillo, Sonora, México.


[email protected]

Keywords: Thin films, semiconductors, Pulsed Laser Deposition, Cadmium Telluride

The purpose of this work is to show the growth correlated with the deposition conditions of CdTe

thin films by means of pulsed laser deposition method. Micrographies were obtained with scanning

electron microscopy featuring top view so much as of transverse sight with different scales of

magnification, which are indicated. The growth conditions of these films of CdTe consisted of

maintaining the substratum to a temperature of 400°C, 100 m of pressure and a frequency of 10 Hz. A

device sketch of a solar cell and description of practical manufacture method with a thickness of 200 nm,

and uniform structure on top of substrate.

P-067

SYNTHESIS AND CHARACTERISATION OF NiMoW CATALYST SUPPORTED ON Ti MODIFIED SBA-15

Silvia Yolanda Gómez Orozcoa, Rafael Huirache Acuñaa, Gabriel Alonso Nuñezb, Eric Mauricio Rivera Muñozc, Bárbara Teresa García Pawelecd.

1 Facultad de Ingeniería Química, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Michoacán, 58060, México.

2 Centro de Nanociencias y Nanotecnología, CNyN, Universidad Nacional Autónoma de México, UNAM, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, 22800, México.


83

3 Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, C.P. 76000 Querétaro, México

4 Instituto de Catálisis y Petroleoquímica, CSIC, Universidad Autónoma de Madrid, UAM, c/Marie Curie 2, Cantoblanco, Madrid, 28049, España.

a [email protected], a [email protected], b [email protected]

Keywords: Hydrodesulfurization (HDS), Dibenzothiophene (DBT)

The hydro-treatment reactions are catalyzed by catalyzers Co(Ni)Mo(W) supported by alumina.

The evidence of a strong interaction of metal-support has generate investigations looking for new kinds of

catalysts. The elevated surface, the uniform size of pore, large wall thickness, porosity texture and

thermal stability are great advantages and they contributed to extend the use of materials mesoporous of

siliceous SBA-15 (pure or superficially modified) as support of the active phases. It is proved that the

SBA-15 support when is superficially modified whit titanium and is used as support for oxide NiMo

catalyzers, the results are highly catalytic activity comparing with the commercial catalyzer CoMo/Al2O3,

based on the reaction of HDS of DBT; which is related whit a better dispersion of the active phases on

surface of the support by the effect of titanium. Based on this and with the propose of search for new

catalyzers of HDS, with more and better catalytic activity, this work studies the effect of SBA-15 support

modified with titanium on HDS of DBT of catalyzers ternaries of Ni-Mo-W.

The mesoporous material of silica with hexagonal structure P6mm SBA-15, was synthesize by

the published procedures of D. Zhao y col. (1998). The modification of the supports with titanium was in

different relations (x=20, 40 y 60), adding titanium (IV) isopropoxide (Ti (i-PrO)4, 97%, Aldrich) as a

forerunner. Each support was charged with a regular amount of molybdenum (13.83% weight as MoO3),

tungsten (17.33 % weight as WO3) y nickel (3.84 % weight as NiO), by simultaneous impregnation by the

method of early stage moisture. The prepared catalyzers and supports was featured by different

techniques; isotherm of adsorption-desorption NH3, XRD, programmed reduction of temperature TPR-H2,

DRS UV-vis, spectroscopy micro-Raman, spectroscopy IR y HRTEM.

P-068

CHARACTERIZATION OF ZIRCONIA THIN FILMS BY ATOMIC LAYER DEPOSITION

J. R. Martinez-Castelo1, a, Tiznado H.2, b and M. H. Farias3, c

1, 2, 3Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, Mexico

[email protected], b [email protected], [email protected]

Keywords: Thin film, Zirconia, ALD, Atomic Layer Deposition


84

Zirconium oxide (ZrO2), is considered a very attractive material for application as dielectric

gate as it exhibits good thermodynamic stability in contact with silicon, has a relatively high dielectric

constant (25 ~ 30), a large gap (5.8 eV), and high compatibility with current manufacturing process of

integrated circuits. The above properties are desirable for the gate dielectric of the field-effect transistor

(FET) and other electronic devices. In order to obtain thin films with specific values of dielectric constant

and bandwidth, a deposition technique that allows controlling the thickness at the atomic level and coat

any surface uniformly, is required. Atomic layer deposition (ALD) is the technique that best fits these

requirements; it is self-limited which ensures that the amount of deposited material is highly controlled; is

able to cover porous surfaces; and does not limit the design of dielectric systems, as it can be applied to a

wide variety of materials.

In this work, ZrO2 thin films were deposited by ALD, using Cp2ZrCl2 (Cp = Ciclopentadienyl) as a

zirconium precursors and water as an oxidizing agent. The films were deposited on silicon substrates

while the temperature used during the deposition process was adjusted to 300°C. Under such conditions, a

deposition rate of ~ 0.3Å (cicle)-1 was obtained. Deposited films were characterized by ellipsometry, and

electronic spectroscopy techniques, for example X-ray photoelectron spectroscopy (XPS). The materials

proposed in this work have high potential for application as MOS capacitors.

P-069

Mn-DOPED 0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3 EPITAXIAL THIN FILMS DEPOSITED BY PLD

A. Gallegos-Melgar1,a, F. Martinez-Suarez1,b, A. I.Gutiérrez-Pérez1,c, N. Lemée2,c, A. Lahmar2,d, F. Espinoza-Beltran1,e, J. Muñoz-Saldaña1,f

1 Centro de Investigación y de Estudios Avanzados del IPN, Santiago de Querétaro, Qro. México

2 Affiliation Laboratoire de Physique de la Matière Condensée (LPMC), EA 2081, Amiens, France

[email protected], [email protected], [email protected], [email protected], [email protected], [email protected]

Keywords: Thin films, lead-free, Mn-doped.

Ferroelectric thin-films based on Pb(Zr,Ti)O3 (PZT) have been utilized to form advanced

electronic devices. Considering the toxicity of lead oxides, there is a general interest in the development

of environmentally friendly lead-free materials. The quasi-binary BNT-BT system ((1-x)(Bi0.5Na0.5TiO3)-

x(BaTiO3)) is a good candidate for the replacement of PZT ceramics. It has been reported that

compositions near the so-called morph tropic phase boundary (MPB) at 6 mol% BT show higher

piezoelectric properties, and doping with different elements such as Mn is used to modify the

microstructure and piezoelectric properties. Mn-doped BNT-BT epitaxial thin films in MPB compositions


85

were grown by pulsed laser deposition. Based on the hypothesis that Bi3+ or Na+ loss can occur during

PLD deposition, stoichiometric thin films were grown using two Mn-doped BNT-BT targets with

different excess of Bi2O3 and Na2CO3. The thin films were grown on <001> SrTiO3 substrates varying

mainly the substrate temperature from 650 to 715 °C, and the oxygen partial pressure in the chamber

between 0.1 and 0.3 mbar. The epitaxial growth of the thin films were in-situ characterized by RHEED

and by X-ray diffraction. The low mosaicity of the films was evidenced by the similar values of the

FWHM of the rocking curve for the substrate and the film. An average grain size of 85 nm and RMS

roughness of 1.2 nm were measured by AFM. The ferroelectric response (by PFM), hysteresis loops,

leakage current and dielectric properties, are currently being measured.

P-070

IDENTIFICATION OF MPB IN (Bi0.5Na0.5) TiO3-(Bi0.5K0.5)TiO3-BaTiO3 CERAMICS BY XRD AND RAMAN SPECTROSCOPY

M. A. Rivera-Gil1,a, A. I. Gutiérrez-Pérez1,b, D. G. Espinosa-Arbeláez1,c, J.A. Eiras2,d ,M. P. Cruz-Jáuregui3,e, J. Muñoz-Saldaña1,f

1 Centro de Investigación y de EstudiosAvanzados del IPN, Unidad Querétaro, Lib. Norp. 2000, Real de Juriquilla, 76230, Querétaro, Qro.México

2 Departamento de Física, Universidad Federal de São Carlos, Rodovia Washington Luís, km 235 - SP 310, São Carlos, Brasil

3 Centro de Nanociencias y Nanotecnología (CNyN)-UNAM.Km. 107, Carr.Tij.-Ens. 22860, Ensenada, B.C., México


[email protected] [email protected] [email protected]

Keywords: Lead-free piezolectric ceramics, morphotropic phase boundary, Raman spectroscopy

The strongest lead-free candidates for substitution of PZT piezoelectric ceramics (due to

international restriction on the usage of lead) are bismuth based perovskites such as (Bi0.5Na0.5)TiO3

(BNT), (Bi0.5K0.5)TiO3 (BKT) and BaTiO3 (BT).BNT crystals are rhombohedral meanwhile BKT and BT

are both tetragonal. At compositions near the morphotropic phase boundaries (MPB), where tetragonal

from rhombohedral symmetries coexist, ferroelectric properties are maximized [1]. The reported MPB

compositions of Bi-based piezoelectric systems as BNT-BT, BKT-BT and BNT-BKT-BT have

discrepancies in a wide range of compositions. This contribution aims to determine the composition

ranges in the MPB of the BKT-BNT-BT ternary system along BKT contents from 5 to 30 mol% keeping

the BT constant at 2.5 mol%. Ceramic samples were prepared by the solid-state reaction method assisted

by high-energy ball milling. The characteristic rhombohedral diffraction peaks (003)/ (021) gives way to


86

a (111) single peak of the tetragonal phase as the BKT content increases, and the single (202)

rhombohedral peak splits into the tetragonal (002)/(200) doublet. The Raman vibrational modes of Na-O

at ~135 cm-1 vanishes as the BKT content increases and the peak shifts to lower wavenumbers. Shifting

to low frequency vibrational modes have been attributed to the mass change of the A site [2]. The

vibrational mode of Ti-O bond and the TiO6 octahedron at ~285 cm-1increases its width and shifts to

lower wavenumber as the tetragonal phase content increases in accordance to the addition of the

tetragonal phase reported for the BNT-BT system. These results are in accordance with the maximum

remnant polarization found at 24.3 mol% of BKT. Thus, it can be implied, that the MPB range can be

foundbetween9 and 25 mol% of BKT.

P-071

OPTICAL NONDESTRUCTIVE EVALUATION OF GALLIUM NITRIDE NANORODS ON SILICON SURFACES WITH GOLD CATALYST

Gregorio Guadalupe Carbajal1, Conett Huerta Escamilla2 and Mufei Xiao2, a

1 Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, 1421 Blvd. Marcelino García Barragán, Guadalajara, Jalisco CP 44430, México


[email protected]

Keywords: GaN nanowires; Chemical vacuum deposition; Gold particle catalyst; Optical reflection

spectroscopy.

Nanometric gallium-nitride rods were grown on a silicon (111) substrate through a chemical

vapor deposition process with gold particles as the catalyst. Randomly distributed gallium-nitride rods of

20nm to 200 nm in diameter and of various densities and lengths were formed under different deposition

conditions. Characterization analyses, such as scanning electron microscopy and optical reflection

spectroscopy have been carried out on samples containing gallium-nitride rods different in size, shape,

length and density. While the scanning electron microscopy shows directly the images of the sample

surfaces, the optical spectroscopy provides a nondestructive evaluation of the sample surfaces, especially

helpful for checking the uniformity of the samples.

P-072

UP-CONVERSION FLUORESCENCE AND OPTICAL THERMOMETRY CHARACTERIZATION OF Er3+:Yb3+ Co-DOPED SrF2 POWDERS

Nikifor Rakov1, Glauco S. Maciel2 and Mufei Xiao2,a

1 Ciência dos Materiais, Universidade Federal do Vale do São Francisco 48902-300 Juazeiro, BA, Brazil


87

2 Instituto de Física, Universidade Federal Fluminense 24210-346 Niterói, RJ, Brazil


[email protected]

Keywords: Up-conversion fluorescence; optical temperature sensor; Er3+:Yb3+:SrF2 powders.

The up-conversion (UC) fluorescence performance of codoped Er3+:Yb3+:SrF2 powders prepared

by combustion synthesis was investigated under near-infrared (980 nm) continuous wave laser excitation.

In order to confirm surface morphology and structure of these Er3+:Yb3+:SrF2 powders, scanning

electronic microscopy (SEM), energy dispersive X-ray (EDX) and X-ray powder diffraction (XRPD)

profiles have been carried out. Spectral UC fluorescence shows bands centered at ~ 410, ~ 522, ~ 545 and

~ 660 nm, corresponding to transitions from upper levels 2H9/2, 2H11/2, 4S3/2 and 4F9/2 to the ground

state 4I15/2 , respectively, and identified as 4f-4f transitions from Er3+ excited states. Furthermore,

targeting to photonics applications, the optical temperature sensor performance of this material was also

investigated and the maximum sensor sensitivity found for our material was 0.00396 K-1.

P-073

FLUORESCENCE DECAY OF A DIPOLAR EMITTER NEAR A PLASMONIC QUANTUM PARTICLE

Mufei Xiao

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, km. 107 Carretera Tijuana-Ensenada, Ensenada, Baja California CP 22860, México

[email protected]

Keywords: Fluorescence; quantum particle, small particle plasmon.

The fluorescence decay process is studied with a self-consistent theory for a dipolar emitter near a

metallic particle that is so small that its plasmonic properties depend significantly on the quantum

confinement of the carriers. The self-consistency enables a rigorous description of the decay in time,

particularly for tightly coupled cases where the distance between the emitter and the particle can be

arbitrarily short or as short as possible. It is found that the decay in time is no longer exponential, and

therefore it becomes inadequate and sometime meaningless to describe the decay process with a simple

decay rate (or a lifetime). On the other hand, the degree of the quantum confinement depends on the size

of the particle and reducing the size causes a red shift as well as a reshape of the spectrum, which, in turn,

influences significantly the behavior of the nearby emitter.

P-074


88

CONTROL AND STABILIZATION OF SILVER NANOPARTICLES SIZE USING POLYVINYLPYRROLIDONE AT ROOM TEMPERATURE.

Ibarra Hurtado JM1,a, Carrillo Torres RC1,b, Eva D. Ruiz1,c , A. Virgen Ortiz2,a, Luna Velasco Antonia3,a.

1 Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, México.

2 Departamento de Ciencias Químico Biológicas, Unidad Regional Sur, Universidad de Sonora, Blvd. Lázaro Cárdenas, No.100 Colonia Francisco Villa, 85880 Navojoa, Sonora México.

3 Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109, Chihuahua, México.


Keywords: Silver nanoparticles, chemical reduction, stability, polyvinylpyrrolidone, hydrazine.

Silver nanoparticles are being considered in a variety of applications ranging from biomedical to

electronic areas. Characteristics such as size, morphology and crystallinity are important parameters to

control for potential applications of nanoparticles. Besides those parameter, the stability of nanoparticles

in aqueous media at room temperature is of vital importance in biological applications. In this study the

main purpose was to optimize the synthesis method of silver nanoparticles by chemical reduction, in order

to obtain spherical nanoparticles with less than 20 nm in size and stable in aqueous media at room

temperature. In the synthesis process, silver nitrate was used as the metal precursor, polyvinylpyrrolidone

as a stabilizer and hydrazine as a reducing agent. The optimization method was mainly based on testing

different concentrations of reactants as well as the modification of temperature and reaction times.The

synthesized silver nanoparticles were characterized in terms of size (primary and hydrodynamic),

morphology, Z potential (surface charge) and absorption spectrum, through the use of advanced

techniques, such as Transmission Electron Microscopy (TEM ), Scanning Electron Microscopy coupled

to Energy Dispersive X-ray Spectroscopy (SEM -EDX), dynamic light scattering mode (DLS), laser

Doppler velocimetry and UV-Visible Spectroscopy. The optimized synthesis method of silver

nanoparticles by chemical reduction, consisted in reacting silver nitrate 25 mM (8 ml) with 1 ml of

hydrazine 70 mM in presence of 0.13 mM polyvinylpyrrolidone at a temperature of 6 °C. Resulting, silver

nanoparticles with spherical morphology of an average size of 16 nm , negative surface charge and stable

in aqueous media at room temperature (for a period > 6 months).

P-075

EFFECT OF pH ON ZnS THIN FILMS GROWN BY CHEMICAL BATH DEPOSITION

P.A. Luque1,a, Claudia M. Gomez Gutierrez1,b, M.A. Quevedo-Lopez2,c and A. Olivas3,d

1 Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California, México


89

2 Department of Materials Science and Engineering, University of Texas at Dallas, USA.

3 Centro de Nanociencias y Nanotecnología-UNAM, C.P. 22860, Ensenada, B.C., México.

[email protected], [email protected], cmquevedo@utdallas, [email protected]

Keywords: Zinc sulfide; Chemical bath deposition; thin films

This work addresses the study of zinc sulfide (ZnS) thin films prepared by chemical bath

deposition. The depositions were carried out in the pH range of 10 to 11. The materials used are zinc

acetate, tri-sodium citrate and thiourea, with tri-sodium citrate being used as complex forming agent.

Structure of these films was characterized by X-ray diffraction (XRD) and scanning electron microscopy

(SEM). Optical properties were studied by spectrophotometric measurements. Influence of the increased

pH value on structural and optical properties is described and discussed in terms of transmission

improvement in the visible range. The morphology of the surface showed that the samples are compact

and uniform, with some pinholes in the surface depending on pH. Transmission spectra indicate a high

transmission coefficient (70%). The direct band gap energy is found to be about 3.67 eV for the films

prepared at pH equal to 11.5. The transmission spectrum indicates an average transmittance of 80 to 87 %

in the spectra range from 300 nm to 800 nm, and the optical band gap of the samples was around 3.68 to

3.76 eV for the films prepared at pH equal to 10.5.

P-076

MOS STRUCTURES SITUABLES FOR APPLICATIONS IN UV DOSIMETERS AND VISIBLE LIGHT DETECTORS

Abraham Arias1,a, Rigoberto Herrera1,b, Nicola Nedev1,c, Mario Curiel1,d, Benjamin Valdez1,e, David Mateos1,f, Roumen Nedev2,g, Oscar Contreras3,h, Diana Nesheva4,i, Emil Manolov4,j, Valeri Dzhurkov4,k, Jesus M. Siqueiros2,l.

1 Institute of Engineering, Autonomous University of Baja California, Benito Juarez Blvd. esc. Calle de la Normal, s/n, C. P. 21280 Mexicali, B. C., Mexico

2 Polytechnical University of Baja California, Calle de la Claridad s/n, C. P. 21376 Mexicali, B. C., Mexico

3 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, A. P. 356, C. P. 22800 Ensenada, B.C. México

4 Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd, 1784 Sofia, Bulgaria

[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected],



90

Keywords: MOS Structures, UV Dosimeter, Silicon Nanocrystals,, Photo-detector, Visible Light, C-V.

The appearance of new electronic products such as smartphones, tablets, cameras, etc increases

the demand of optoelectronic devices compatible with the up to date silicon technology. In this work we

present results for two types of Metal-Oxide-Semiconductor (MOS) structures suitable for application in

UV dosimeters and optical sensors. The first type of structure is a MOS capacitor which contains Si

nanocrystals (Si NCs) in the gate dielectric. The nanocrystals were grown by high temperature annealing

of SiO1.3 at 1000 oC for 60 min. This annealing process leads to complete phase separation and formation

of Si NCs with diameter of ~3-4 nm in a SiO2 matrix. A semitransparent Au film with thickness of ~ 10

nm was used as a top electrode. The structures can be charged negatively by injecting electrons from the

Au electrode in the dielectric which remain trapped in the nanocrystals. The effect of UV light was

studied by illumination of the samples using a 395-400 nm, 5 mW source. The UV irradiation causes

discharge of nanocrystals with a rate which varies in the range 2.5 mV/s - 5 mV/s. The discharge rate

depends on both the internal electric field in the gate dielectric and the applied gate voltage during

illumination. Preliminary experiments were carried out with MOS structures without nanocrystals and it

was shown that they can be employed in visible and near UV light detectors. The output signal is the

variation of the inversion capacitance under light illumination at a given bias. Some advantages of such

sensors are small size, weak dependence on the temperature and very low power consumption.

P-077

CL FROM IMPURITIES AND POINT DEFECTS IN ZnO:Mn NANORODS GROWN BY THE HYDROTHERMAL METHOD

A. A. Guerrero1,a and M. Herrera1,b


a [email protected], b [email protected].

Keywords: Tin oxide, nanostructures, point defects.

Cathodoluminescence (CL) is used to investigate the nature of defects and impurities generated

in ZnO: Mn nanorods grown by the hydrothermal method. The incorporation of Mn in the ZnO nanorods

generated an increase in the surface roughness and the formation of a Mn complex-compound of spinel

ZnMn2O4. CL measurements acquired at room temperature revealed two emissions at 3.2 and 2.3 eV,

associated with the ZnO near-band-edge emission and the luminescence of spinel ZnMn2O4, respectively.

CL spectra at 100 K recorded the Mn2+ ion d–d transitions as a broad CL emission, with energies between

2.6 and 3.1 eV. The well-known ZnO yellow emission (2.0 eV) was also present in the samples, recording


91

a relative intensity ratio I2.0/I2.33 that increased when the temperature was dropped at 100 K. A thermal

annealing of the samples at 400 C, in Ar atmosphere, generated strong decreases in the intensity of the

defects and Mn-related emissions, recording an intensity ratio Iband-edge/Idefects of about 15. Diffusion of Mn

from the ZnO surface to the bulk is proposed to explain this effect.

P-078

INTERACTION OF GOLD NANORODS WITH A MODEL MEMBRANE AT THE AIR-WATER INTERFACE

Almada Mario1, a, Valdés Miguel1, b Ibarra Jaime1, c and Juárez Josué 1, d

1 Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, México

[email protected], b [email protected], c [email protected] [email protected]

Keywords: Gold, Nanorods, Langmuir, isotherms.

Gold nanorods exhibit a surface plasmon resonance in the near infrared, making them very

interesting for use as agents for treating several diseases by phototherapy. Recently, it has been proposed

to use these nanoparticles to degrade amyloid fibrils causing Alzheimer’s disease. For this, is necessary

that the particles can be able to overcome the blood-brain barrier. The Langmuir trough is a tool that

allows the construction of models membrane at the air-water interface and can be utilize to study the

biophysical interactions of several molecules or particles with the monolayer, in this way it is possible to

predict its ability to penetrate or disturb the cell membrane. In this work we assess the interaction of gold

nanorods with a model membrane with a phospholipid mixture similar to which compose the endothelial

cells of a blood-brain barrier. The gold nanorods were synthesized with the seed-mediated method and

were characterized by UV-Vis spectroscopy, AFM, DLS and Zeta Potential. The monolayer was

characterized by pressure-area isotherms with PBS as subphase and it was assessed the effect of nanorods

in the isotherm. The ability of nanorods to penetrate or disturb the monolayer was assessed by monitoring

changes in the pressure after addition of the particles at different initial pressures; Langmuir-Blodgett

films were obtained, which were characterized by AFM and Infrared spectroscopy.

P-079

DIRECT FEMTOSECOND LASER WRITING AND MONITORING OF WAVEGUIDE-LIKE PATTERNS OVER SILVER NANOPARTICLES SYSTEM EMBEDDED IN SILICA USING NONLINEAR MICROSCOPY

Jacob Licea-Rodríguez1,a, Israel Rocha-Mendoza1,b, Raúl Rangel-Rojo1,c, Luis Rodríguez-Fernández2,d

and Alicia Oliver2,e


92

1 Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana No. 3918, Zona Playitas, 22860, Ensenada, Baja California, México

2 Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica S/N, Ciudad Universitaria, Distrito Federal, México

a [email protected], b [email protected], c [email protected], d [email protected], [email protected]

Keywords: Nonlinear optical materials, metallic nano-particles, nonlinear microscopy

Nanostructured materials composed of metal nano-particles (NPs) are promising materials for

photonics nano-devices and plasmonic circuitry. These composite materials have also nonlinear optical

properties that could be considered as a plus for the very same purposes. By means of second harmonic

generation (SHG), and z-scan experiments, we have recently studied the second- and third-order

nonlinearity, respectively, of randomly organized spherical and elongated (but aligned in a preferred

direction) silver nanoparticles (Ag-NPs) embedded in silica. We have found that both the linear and

nonlinear optical properties strongly depend on the nanoparticle geometry, size, and distribution, which

are physical parameters that can be controlled relatively easy during the formation process of the

composites. The composites with spherical NPs are produced by ion-implantation of silver nanoparticles

over silica glass followed by a temperature annealing process. The composites with elongated NPs are

produced by a second irradiation of Si ions over the composites with spherical NPs. In this context, we

are now generating waveguide-like patterns over our Ag-NP’s samples by using fs-laser irradiation and

characterizing them using a custom made nonlinear SHG microscopy, respectively. In this work we

present our preliminary results and discuss them as a proof of principle toward the generation of optical

waveguides for nonlinear optical switching.

P-080

SYNTHESIS AND CHARACTERIZATION OF BERYLIUM ALUMINATE DOPED WITH EUROPIUM AND DYSPROSIUM (BeAl2O4:Eu2+,Dy3+) THROUGH COMBUSTION SYNTHESIS

P. Tirado1a, R. García-Gutierrez1, J.A. Montes1b, M. Barboza-Flores1c, , O. E. Contreras2

1 Departamento de 1Investigación en Física, Universidad de Sonora, Hermosillo,Sonora, 83000,México Universidad de Sonora, Hermosillo, Sonora, 83000, México

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada B.C., 22800, México

1 [email protected] , [email protected]

Keywords: Beryllium Aluminates, Semiconductor Materials.


93

Beryllium aluminates doped with Eu+2 and Dy+3 are expected to show a high stability, very

high quantum efficiency and long persistence luminescence in the green region of the visible spectrum. A

new method to synthesis this doped beryllium aluminates powder is presented in this work. Usually,

similar materials are synthesized through a solid-state reaction, the precursor mixture, including initiators

as SrO, Al2O3, Eu2O3 and Dy2O3, under temperatures around 1400°C for more than 10 hours. We are

presenting a novel method which aluminates beryllium powders doped with europium and dysprosium

were synthesized through combustion, involving a violent exothermic redox reaction between the metallic

nitrates, Al(NO3)3, Be(NO3)2, Eu(NO3)3 and Dy(NO3)3and the organic fuel carbohydryzide (CH6N4O) in a

fraction of time, and a considerable energy saving. It is also possible to control particle size with this

technique that ranges from micrometers to nanometers. To obtain the aluminates, the molar quantities of

the precursors were respected and only the molar quantity of the fuel was changed (from 1 mole to 4 mole

of carbohydrizide), once obtained the samples, the powder was analyzed with the purpose to obtain

results that indicate physical or structural changes with respect to similar materials. Thermo luminescence

and optical stimulated luminescence analysis were also conducted. The results of analysis will be

presented during the presentation.

P-081

MAGNETIC MOMENT DISTRIBUTION IN SFmo RELATED MATERIALS

J. Pilo1, E. Carvajal1,a, R. Oviedo-Roa2, M. Cruz-Irisson1 and O. Navarro3

1 ESIME-Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana 1000, C.P. 04430, México, D.F., México.

2 Programa de Investigación en Ingeniería Molecular, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, 07730, México, D.F., México.

3 Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, A.P. 70-360, 04510, México, D.F., México.

a [email protected]

Keywords: fuel cells, double perovskites, magnetic moments, clusters.

The double perovskite Sr2FeMoO6 (SFMO) has been widely studied because of their magnetic

properties; being a half-metallic material has a huge potential to be employed in the development of

spintronic devices. It is known that different double perovskite compounds vary their physical behavior

depending on the different concentrations of the metal atomic species. In this work, starting with the

conventional SFMO double perovskite and using a supercell to obtain different iron rich compounds with

formula Sr2Fe1+xMo1-xO6, the bulk materials and some clusters excised from them, were studied. Within

the Density Functional Theory (DFT) scheme, with the Generalized Gradient Approximation (GGA),


94

with the Perdew–Burke–Ernzerhof (PBE) functional and fine-accuracy options for all runs, the magnetic

moments for each atomic species were studied; also, the molecular orbitals around the Fermi level and the

related magnetic behavior were discussed for these compounds. A similar analysis was made for the

clusters, around the highest occupied and lowest unoccupied molecular orbitals, seeking for light about

which states are favoring the different magnetic behaviors shown by the studied materials.

Acknowledgments: This work was partially supported by the multidisciplinary project 2014-1641 from

SIP-Instituto Politécnico Nacional, COFAA-IPN, PAPIIT-IN100313 from Universidad Nacional

Autónoma de México and 131589 from Consejo Nacional de Ciencia y Tecnología (CONACYT). J. Pilo

wants to acknowledge the scholarship from CONACYT.

P-082

IONS ENERGY IN A DOUBLE PEROVSKITE AND THEIR RELATED CLUSTERS

J. L. Rosas1, E. Carvajal1,a, R. Oviedo-Roa2, M. Cruz-Irisson1 and O. Navarro3

1 ESIME-Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana 1000, C.P. 04430, México, D.F., México.

2 Programa de Investigación en Ingeniería Molecular, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, 07730, México, D.F., México.

3 Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México,A.P. 70-360, 04510, México, D.F., México.

a [email protected]

Keywords: fuel cells, double perovskites, energy, ions, clusters.

The solid oxide fuel cells (SOFC), among the diverse fuel cells, have shown as an alternative to

produce electricity in a more efficient and clean way to face environmental problems. Hence, great efforts

are focused on the research and development of devices in SOFCs, being one of the challenges to develop

electrode materials that are good mixed ionic and electronic conductors (MIECs); although there are

already commercially used materials, the understanding of the physical processes at the nanometer scale

will give us a better understanding for the development of best materials. With this understanding, the

Sr2Fe1+xMo1-xO6 compounds and some clusters excised from them were studied in this work. The energies

associated with certain ions placed at high symmetry points within and around the structures were

calculated; the aim is to make a proposal about the route taken by the species, to get more efficient power

generation in SOFCs. Single-point energy calculations were performed using the DMol3 module in the

generalized gradient approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE) functional and fine-

accuracy options for all runs. Acknowledgments: This work was partially supported by the

multidisciplinary project 2014-1641 from SIP-Instituto Politécnico Nacional, COFAA-IPN, PAPIIT-


95

IN100313 from Universidad Nacional Autónoma de México and 131589 from Consejo Nacional de

Ciencia y Tecnología (CONACYT). J. L. Rosas wants to acknowledge the scholarship from CONACYT.

P-083

STUDY OF THE MORPHOLOGY OF TETRASPHAERA DUODECADIS

E. Arroyo1,a, Marcela Ovalle M1,b, L. Enríquez 2,c, A. Sánchez3,d, A. Olivas1,e

1 Centro de Nanociencias y Nanotecnología-UNAM, México.

2 Fac. Ciencias Marinas-UABC, Ensenada, B. C., México.

3 CICESE, Ensenada, B.C. México.

aearroyo@ cnyn.unam.mx, [email protected], [email protected], [email protected], [email protected]

Keywords: Scanning electron microscopy; Tetrasphaera duodecadis; Growth curve; Freeze-dryer.

Here we present a study of the Tetrasphaera duodecadis bacteria. In order to evaluate the

morphological characteristics of the Tetrasphaera duodecadis bacteria Scanning Electron Microscope

(SEM) was used throughout its different growth stages. These microorganisms were grown in B12

vitamin broths with 1% tryptone, 0.2% yeast extract, 0.1% glucose. The turbidimetric method was

employed for the determination of bacterial concentration and for achieving establishes the bacterial

growth curve. The SEM results show small agglomerates, called cocci, of 0.8 ± 0.05 μm in the lag phase,

and rod-like shapes of 3.5 ± 0.5 μm during the exponential phase with similar shapes in the stationary

phase.

P-084

REVIEW OF THE EFFECTS CYTOTOXICS SILVER NANOPARTICLES IN FRESHWATER MICROALGAE

Elva Guadalupe Robles Jarero1,a, Francisco Javier Gálvez Gastélum2,b Irinea Yáñez Sánchez3,c Celso Velázquez Ordóñez 4,d y María Luisa Ojeda Martinez5

1 Centro Universitario de Ciencias Biológicas y Agropecuarias-Universidad de Guadalajara, Carretera a Nogales, Km 15.5, Zapopan, Jal. México

2 Centro Universitario de Ciencias de la Salud- Universidad de Guadalajara. Sierra Mojada 950, Colonia Independencia, C.P. 44350

3, 4, 5 Centro Universitario de los Valles- Universidad de Guadalajara. Carretera Guadalajara - Ameca Km. 45.5, C.P. 46600, Ameca, Jalisco, México.



96

Keywords: Freshwater microalgae, effects cytotoxic, Mexico

Silver nanoparticles (1-100 nm) are widely used in therapeutics, manufacture of cosmetics and

household products due to their potential antibacterial power. According to their size, are not retained by

the filters wastewater, and can reach the aquatic environment through urban and industrial discharges,

rain and air pollution, affecting primary producers. In studies conducted in the field and in experimental

environments with plants and microorganisms showed adverse reactions after a single dose of silver

nanoparticles, decreasing by one third the biomass of these organisms and causing genetic damage. At

present there is a lack of safety regulations in practice for the use of these nanoparticles, and in our

country, having interactions with cells, their mechanisms of consumption, distribution, excretion, and

toxicological endpoints mechanisms are unknown action. Therefore, it is important to understand at a

deeper level the effects of silver nanoparticles in freshwater microalgae and the ecological impact of its

indiscriminate use in aquatic ecosystems.

P-085

SYNTHESIS OF SILVER NANOPARTICLES USING POLY(ETHYLENE GLYCOL) AND POLY(VINYL ALCOHOL) AS STABILIZING AGENTS, BY A GREEN CHEMISTRY REDUCTION METHOD.

Cesar Diaz-Cruz1, Gabriel Alonso-Nuñez2, Heriberto Espinoza-Gómez3,a, Lucía Z. Flores-López1,b.

1 Centro de Graduados e Investigación, Instituto Tecnológico de Tijuana, Apartado Postal 1166, Tijuana, B. C., México.

2 Centro de Nanociencias y Nanotecnología. UNAM-Ensenada. Km 107 Carretera Tijuana-Ensenada. Apdo Postal 14, C.P. 22800, Ensenada, B.C. México.

3 Facultad de Ciencias Químicas e Ingeniería. UABC. Calzada Universidad 14418Parque Industrial Internacional, C.P. 22390 Tijuana, B.C. México.


Keywords: Silver Nanoparticles, poly(ethylene glycol), poly(vinyl alcohol), green synthesis.

Today, the role that plays green chemistry in nanotechnology is very important, in the synthesis

of diverse nanomaterials. In green chemistry, the election of non-toxic solvents, biodegradable materials

and low-cost green chemicals, are key factors for the election of an ideal stabilizer, reaction medium, and

green reducing agent; in the synthesis and stabilization of metallic nanoparticles. In recent years, has

increased the interest for the use of Ag and is considered one of the most studied metal, due to the

antibacterial, antiviral and antifungal properties it possesses. Here we report the research work of the

green synthesis of silver nanoparticles (AgNPs), with the chemical reduction method. Silver nitrate

(AgNO3) was used as the metal salt precursor, poly(ethylene glycol) (PEG) and poly(vinyl alcohol)


97

(PVA) aqueous solutions of different molecular weight, as stabilizing and reducing agent. The green

synthesis of the silver nanoparticles was carried out in water, without organic solvent, safely, and in a

single step; that represent a very effective environmental synthetic route. The silver nanoparticles were

characterized by UV-Vis, AFM, SEM-EDS and TEM. The main objective of this work is determined how

the molecular weight of poly (ethylene glycol) and poly(vinyl alcohol) affects the morphology, and size

distribution of the AgNPs obtained.

P-086

BIO- ACCUMULATION OR BIO- MAGNIFICATION IN, CORN AND SUGARCANE, AT THE LEVEL OF NANOPARTICLES.

Maciel-Flores R.1,a; Peña García L. E.1.; Rosas-Elguera J.2; Alatorre-Zamora M.A.3 y García-Velasco J.

1 University Center for Biological and Agricultural Sciences, University of Guadalajara,

2 University Center of the Valleys. University of Guadalajara

3 University Center of Exact Sciences and Engineering. University of GuadalajaraCamino Ramón Padilla Sánchez Nextipac # 2100, Zapopan, Jalisco México.

[email protected]

Keywords: Nano-particles, bio-accumulation, Bio-magnification, Arsenic, Ameca Jalisco.

In the upper part of the Ameca Basin, located within the states of Jalisco and Nayarit, a water

analysis of the Ameca River used on crops, which is partially geothermal water, was conducted in

December 2013, considering the following standards NMX -AA- 005- SCFI -2000, EPA - 6010B, NMX -

AA- 026- SCFI- 2001 NMX -AA- 008- SCFI -2000 and NMX NMX -AA -AA -058 -30- SCFI -2001 -

SCFI -2001. Arsenic (0.0798 mg / L), boron (4.532mg / L) and Phosphorus (0.7995mg / L) were found in

the water among other items. In order to determine whether these elements are present in the cultures of

the area, nine samples taken in the field were analyzed by different techniques, used compost, soil, corn

and sugarcane. To determine whether bioaccumulation or bio- magnification of the above, at the level of

nanoparticles, electron microscope elements scanning (JSM-6610 in the Centro de Instrumentación

Transdisciplinaria y de Servicios of the Universidad de Guadalajara), was used in the samples collected.

For each sample, three different quadrants of on thousand µm2 magnified up to 50μm, were performed,

so that in the 27 analysis the presence of food items listed in the area irrigated with such water was not

found. Using a scanning electron microscope, can help determine if a food has substances that can be

harmful to the health of the consuming population. In this case it was shown that no bioaccumulation or

bio-magnification exists in crops.

P-087


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ELECTRICAL PROPERTIES OF TERNARY CU3NPdX

I. Ponce1,3,a, Ma. Guadalupe Moreno-Armenta2,b, G. Soto2,c, and W. De laCruz2,d

1 Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Tijuana- Ensenada No. 3918, A. Postal 360, 22860, Ensenada B.C., México

2 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada, C.P. 22860, Ensenada B.C., México

3 Facultad de Ingeniería, Arquitectura y Diseño, UABC, Ensenada B.C., México

a [email protected], b [email protected], [email protected], [email protected]

Keywords: Copper-palladium Nitride, Reactive Sputtering, electrical properties, Semiconductor.

Copper nitride (Cu3N), an excellent semiconductor with many extraordinary properties due to

nontoxic stable in air at room temperature and low thermal decomposition temperature, and it is a

semiconductor with small band gap (0.9-1.9 eV) . Copper nitride (Cu3N) has an anti-ReO3 structure in

which Cu atoms do not occupy perfectly the closely packed sites on (111) planes . Recently, it was found

that is possible to insert transition metal atoms into the Cu3N structure to induce significant changes in

electrical properties. The ternary Cu3NPd films, with Pd concentrations up to 21.7 at. % were successfully

synthesized by reactive magnetron sputtering using copper target modified by the insertion of palladium

pellets. XPS and XRD data strongly suggest that Pd atoms occupy the centers of the Cu3N unit cells

rather than simply substituting for the Cu atoms. A reduction in the electrical resistivity by five orders of

magnitude was observed when the Pd concentration increases from zero to 21.7 at. %. All deposits with

Pd exhibit an n-type conductivity behavior. All this indicates that it is an interesting material for

promising applications on nano-electronic and nano-photonic devices. Acknowledgments: The authors

are grateful to D.A. Domínguez, E. Aparicio, J.A. Díaz , A. Tiznado, and E. Medina for valuable

technical assistance. This work was partially supported by Dirección General Asuntos del Personal

Académico (DGAPA) projects IN107213 and IN103711. IPC received a scholarship from Consejo

Nacional de Ciencia y Tecnología (CONACyT), Mexico.

P-088

STUDY OF THE COPPER-GOLD NITRIDE FORMATION

I. Ponce1, 3,a, Ma. Guadalupe Moreno-Armenta2,b, G. Soto2,c and W. de la Cruz2,d

1 Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Tijuana_Ensenada No. 3918, A. Postal 360, 22860, Ensenada B.C., México

2 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada, C.P. 22860, Ensenada B.C., México


99

3 Facultad de Ingeniería, Arquitectura y Diseño, UABC, Ensenada B.C., México

a [email protected], b [email protected], [email protected], [email protected]

Keywords: Ab- initio calculations, Hall effect measurements, Intermetallic compounds, Reactive

Sputtering, Copper-Gold Nitride.

This work investigates the formation of Cu3Au-nitride intermetallic compound using

experimental and computational methods. The intermetallic was deposited as thin film by sputtering on

glass substrates, using a custom-made Cu-Au target. For all films, DC power was 30 W during the

sputtering. The working and reactive gases were Ar and N2, respectively; the purity of the gases was

99.999%. In this work, nitrogen flows were 3 to 6 sccm, and argon flow was kept constant at 5 sccm. The

deposition time for each sample was 20 min and the pressure during the deposits was 20 mTorr. The

structure and composition of the thin films were characterized by spectroscopic and diffraction

techniques. The mobility, carrier concentration and electrical resistivity were obtained from Van der

Pauw method at room temperature. Using first principles calculations a structural model was constructed

that harmonize with the experimental observations. The crystalline system was cubic, Pm3m space group,

with half and randomly filled Au-sites. The composition was close to Cu3Au0.5N. In agreement with the

electric measurements and the calculations, the Cu3N band structure was highly affected by the Au, where

Au acts like donor. The material was a semiconductor with high conductance at room temperature, which

gives it great potential for use in optoelectronics industry. Acknowledgments: The authors are grateful to

D.A. Domínguez, E. Aparicio, J.A. Díaz , A. Tiznado, and E. Medina for valuable technical assistance.

This work was partially supported by Dirección General Asuntos del Personal Académico (DGAPA)

projects IN107213 and IN103711. IPC received a scholarship from Consejo Nacional de Ciencia y

Tecnología (CONACyT), Mexico.

P-089

POLARIZATION SELECTABLE NONLINEAR RESPONSE OF ELONGATED AG NANOPARTICLES EMBEDDED IN SIO2 STUDIED BY THE Z-SCAN TECHNIQUE

Bonifacio Can Uc1,a, Raúl Rangel Rojo1,b , Luis Rodríguez Fernández 2,c and Alicia Oliver 2,d

1 Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada Tijuana No. 3918, Zona Playitas, C.P. 22860, Ensenada, B. C. México.

2 Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica S/N, Ciudad Universitaria, Distrito Federal, México.



100

Keywords: Nonlinear absorption, nonlinear refraction, Elongated nanoparticles

We report the study of the nonlinear response of a composite material consisting of elongated

silver nanoparticles that are aligned in a preferential direction. The nanoparticles are contained in a thin

layer embedded in a silica host. The absorptive and refractive contributions to the nonlinearity of the

sample were studied using the z-scan technique with 80 fs pulses at 825 nm. The nonlinear response was

studied as a function of the intensity, and the polarization angle of the light. A large anisotropy was

observed in both the refractive and absorptive contributions to the nonlinearity. The fast electronic and

slow thermal contributions to the nonlinear response were resolved by conducting experiments using a

chopper to change the thermal load to the sample, while maintaining a constant peak irradiance.

P-090

PARTICULAS ULTRAFINAS DE METALES PESADOS EN LEAVES FICUS, METROPOLITAN AREA GUADALAJARA, JALISCO. MEXICO

Laura Elizabeth Peña-García1,a, Roberto Maciel Flores1 Javier García Velasco1, Francisco Bautista Zúñiga2, José Rosas Elguera3, Víctor Rentería Tápia3, Malva Liu Gonzalez4 Laura Elizabeth Peña-García. Ponente

1 Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara- Camino Ramón Padilla Sánchez #2100 Nextipac, Zapopan, Jalisco México.

2 Centro de Investigaciones en Geografía Ambiental – UNAM, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta. C. P. 58190. Morelia, Michoacán, México.

3 Centro Universitario de los Valles, Universidad de Guadalajara. Carretera Guadalajara - Ameca Km. 45.5, C.P. 46600, Ameca, Jalisco, México.

4 Servicio Central de Soporte a la Investigación Experimental (SCSIE)-Universidad de Valencia. Dr Moliner, 50 - Edificio de Investigación, Lab -1.46/-1.51. 46100 Burjassot – Valencia

[email protected]

Keywords: Leaves Ficus; heavy metals less than 1 micron; health effects; metropolitan area of

Guadalajara.

This work was carried out on March 30 2013, in the metropolitan area of Guadalajara (ZMG),

Jalisco, Mexico, covering an area of 2,734 km2 where sampling Ficus tree leaves was performed. The

ZMG worked with 11 field teams swept the entire work area, which was divided into quadrants each 2

km2, sampling was done in the center of each quadrant. Once at the site trees over 3 meters in height,

where 30 mature leaves were collected were selected. The objective was to determine the contamination

by heavy metals in breathable level, about 1.30 meters tall. Each fraction was analyzed in leaf scanning

electron microscope JSM- 6610 in the Instrumentation Center and Trans disciplinary Services University

of Guadalajara. Samples were observed on a scale of less than 1 micron, looking generally heavy metals.


101

In 72% of them were found tantalum, zirconium and 55% tungsten, 27 % platinum, thallium and mercury

in 18% of samples. Specifically copper, nickel, cadmium, cobalt, arsenic which is found in 82% of

samples was sought. Zinc, titanium, Vanadium in 45% of them. 36% lead and 27% of chromium in the

samples. The health effects of metals found as well as the distribution and origin of them in the ZMG are

analyzed.

P-091

AB-INITIO STUDY OF In, Ru-DOPED CeO2

Roberto Núñez-González1, a,Ricardo Rangel2, Donald H. Galván3 and Álvaro Posada-Amarillas4

1 Departamento de Matemáticas, Universidad de Sonora, México.

2 Universidad Michoacana de San Nicolás Hidalgo, México.

3 Centro de Nanociencias y Nanotecnología, UNAM, México.

4 Departamento de Investigación en Física, Universidad de Sonora, México.

[email protected]

Keywords: DFT, electronic structure, ceria doped.

Structural and electronic properties of Ceria doped with Indium and Ruthenium were calculated

using the Full-Potential Augmented Plane Waves with local orbital Method (APW+lo), within the

Density Functional Theory. DFT calculations were performed for 1x1x2 and 2x2x2 super cells using

GGA and hybrid exchange-correlation potentials. For each cell the atoms were relaxed by minimizing

forces. Geometric and band structure results were examined and a comparison with pure ceria structural

and electronic properties was performed. R.N.G. acknowledges support from DCEN13-PI06 project.

R.N.G. acknowledges computational support from ACARUS-UNISON.

P-092

IMMOBILIZATION OF YARROWIA LIPOLYTICA LIPASE 2 ON LAYERED DOUBLE HYDROXIDES

Ivanna Rivera 1,a, Gregorio Carbajal 2,b, Georgina Sandoval 1,c

1 Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco (CIATEJ). Av. Normalistas 800. 44260 Guadalajara, Jal., México.

2 Departamento de Química. Universidad de Guadalajara. Marcelino García Barragán 1429. 44430 Guadalajara, Jal., México.

a [email protected], b [email protected], c [email protected], g sandoval@ciatej,mx

Keywords: Lipase, immobilization, adsorption, layered double hydroxides, nanoclays


102

The variety of morphologies in nanostructures such as nanoporous particles, nanofibers,

nanotubes and nanolayers, as well as their particular physicochemical properties, result attractive for

enzyme immobilization. Layered double hydroxides (LDH), classified as synthetic clays, are

nanoparticles whose structure can be tuned with different degrees of hydrophobicity, or even with

functional groups capable to immobilize enzymes through adsorption or with covalent bonds with

different compounds such as aluminum, zinc, chloride, etc. Lipases are one of the most used enzymes in

organic synthesis and these are versatile for applications in food, pharmaceutics, cosmetics, polymers and

energy industries. In this work, we report the immobilization of lipase 2 from Yarrowia lipolytica by

adsorption on LDH synthetized by our working group (three types of double layered zinc/aluminum

hydroxides and one zinc hydroxide). Interestingly, immobilizes shown activity only on LDHs having

aluminum. Other properties of the immobilized lipase, like substrate preference, optimal temperature,

thermostability and solvent resistance, were also evaluated.

P-093

TITANIUM DIOXIDE NANOTUBES IN SOLAR CELLS

F. Córdova1,a, A. Gaxiola1,b and L. Huerta1,c

1 Universidad de las Américas-Puebla, Escuela de Ciencias, Departamento de Ciencias Químico-Biológicas. Laboratorio de Nanotecnología, Ex-hacienda de Sta. Catarina Mártir, San Andrés Cholula, Puebla, México


Keywords: Titanium dioxide nanotubes, solar cells, dyes, sensitizers.

In this study we present the results of solar cells sensitized by N3 dye coupled to titanium dioxide

nanotubes (DSSC-TiO2 NT). The nanotechnology has developed many structures where the surface to

volume ratio of this kind of materials has been an important parameter to control many process. In the

conversion of light energy to electric energy the electron transfer depends principally of the surface

structure of photoanode material. In this regard, the nanotube structure offer a vast surface area to

promote this electron transfer. In this manner, the rapid electron transfer makes that the energy efficiency

conversion of this photoelectrochemical devices could be improved. Additionally, if the electron transfer

of the excited molecule to nanostructure photoanode is compensated with a good performance at the

cathode, this produce an excellent regeneration of dye molecules via a redox reaction with the electrolyte

components. In this case, the best cathode material has been proposed as a Pt electrode supported on ITO

material. Therefore in this work the DSSC-TiO2 NT has been built generating TiO2 NT by an

electrochemical method on ITO substrate and Pt cathode by a pyrolysis technique from a Pt solution. The


103

evaluation of energy conversion has shown that the DSSC-TiO2 is better than the DSSC using TiO2

nanoparticles.

P-094

PHOTOCATALYSIS OF DYE COMPOUNDS WITH TiO2-AG NP

F. Córdova1,a and D. Rosas1,b

1 Universidad de las Américas-Puebla, Escuela de Ciencias, Departamento de Ciencias Químico-Biológicas. Laboratorio de Nanotecnología, Ex-hacienda de Sta. Catarina Mártir, San Andrés Cholula, Puebla, México


Keywords: Photocatalysis, Organic Compounds, Nanoparticles, Advanced Oxidation Process.

Advanced oxidation processes (AOP) has been an alternative to incineration processes to destroy

hazardous material. In this processes a strong agent oxidant is generated for example with the use of

photons. In this case, the OH radicals are formed on the surface of semiconductor materials. Doping the

semiconductor materials could be an alternative for expanding the activity of semiconductors onto the

visible part of the electromagnetic spectrum. Therefore in the present work the results of removal color of

sodium3-hydroxy-4-(2-hydroxy-1-naphthylazo)-1 naphthalenesulphonate best known as mordant black

17 are presented. The results have showed that the removal color depends on Ag content present in TiO2

nanoparticles which has been obtained by sol-gel method, being 1.5 w/w % Ag content the best

concentration used in the photocatalyst. At this concentration a 95.5 % of removal color is reached in a 2

hr reaction time. SEM analysis of the semiconductor doped Ag nanoparticles have shown that the

nanoparticles as-obtained have a size average of 80 nm which in solution were highly stable.

P-095

MOLECULARLY IMPRINTED SILICON NANOPARTICLES: RECOGNITION OF 3-HYDROXYFLAVONE

Gracia-Soto,R.A.1,a, Aguilar-Garcia, D.G.1,b y Pina-Luis, G.*1,c


[email protected], b [email protected], [email protected].

Keywords: Molecularly imprinted polymer, silica nanoparticles, molecular recognition, 3-

hydroxyflavone

The molecular imprinting technique has been successfully employed in recent years in the

formation of highly specific artificial sites of recognition for determining a template molecule through


104

non-covalent interactions in a host-guest system. Recently, several research groups have explored an

alternative developing of imprinted nanomaterials, which have very small dimensions with a very high

surface to volume ratio, which ensures than most of the molecules are located in the surface. This leads to

imprinted polymer with a lot of recognition sites on the surface where the template can be adsorbed and

desorbed easily. So imprinted nanomaterials improve: binding capacity, kinetic of binding sites and

accessibility of imprinted materials. In this work we report the synthesis of imprinted silicon

nanoparticles (NpSiO2) for the recognition of 3-hydroxyflavone. The NpSiO2 were synthesized by the

hydrolysis of the alkoxide precursor tetraethylorthosilicate (TEOS) in aqueous ammonia medium. The

molecular impression of NpSiO2 is performed using a sol-gel process where the complex of pre-

polymerization between 3-hydroxyflavone and monomer aminopropyltriethoxysilane (APTES) is formed

and TEOS as cross linking agent is added in an acidic medium. A non- imprinted polymeric material

(control) was also prepared in the absence of template molecule. The NPSiO2 before and after the

molecular impression of the 3-hydroxyflavone (NpSiO2 - 3-hydroxyflavone) were characterized using the

techniques of dynamic light scattering (DLS), infrared (IR), scanning electron microscopy (SEM) and

transmission electron microscopy (TEM). The interaction of the imprinted NpSiO2 and control were

evaluated against 3-hydroxyflavone. The adsorption isotherms and the kinetics of binding were

determined. The intermolecular interaction of 3-hidroxyflavone-APTES was confirmed by HNMR and

molecular fluorescence; this interaction indicated a monomer-template ratio 1:1, confirming the existence

of a pre-polymerization complex.

P-096

BIOSYNTHESIS OF ZnO NANOSTRUCTURES USING AQUEOUS MUCILAGE

J.Francisco-Escudero1,a, C.A.Lucho-Constantino2,b,M.A.Flores-González1,c,M.Villanueva-Ibáñez1,d

1 Nanotecnología y Sistemas Inteligentes- Universidad Politécnica de Pachuca Carr. Pachuca-Cd. Sahagúnkm 20, Rancho Luna, Ex-Hacienda de Santa Bárbara. Zempoala, Hidalgo. CP. 42830. MEXICO

2 Departamento de Biotecnología- Universidad Politécnica de Pachuca Carr. Pachuca-Cd. Sahagún km 20, Rancho Luna, Ex-Hacienda de Santa Bárbara. Zempoala, Hidalgo. CP. 42830. MEXICO


Keywords: ZnO nanoparticles, mucilage, biosynthesis

ZnO nanoparticles have been studied, because exhibit antibacterial, antifungal, optical,

photochemical and electrical activity. ZnO nanoparticles possess various applications in several

nanosystems such as optoelectronic devices, biosensors or as a pigment in the production of paints.

Different methods have been reported to prepare ZnO nanoparticles, however most of them require


105

expensive high technology or rely on the use of organic solvents and toxic reducing agents. Green

synthesis by plant extracts is a method relatively simple and low cost, only few plants have already been

reported to synthesize ZnO nanoparticles such as Calotropis procera, Citrus aurantifolia and Aloe

barbadensis Miller. In Mexico the tender cladodes of Opuntia amychlaea are used for human

consumption, but the cladodes of more than one year old are considered like residues. Opuntia amychlaea

is characterized by the production of a hydrocolloid known as mucilage. In this work we report a simple

green synthesis by using the aqueous mucilage of Opuntia amychlaea to obtain ZnO nanoparticles. ZnO

nanoparticles have a maximal UV-Vis absorption at 350 nm. XRD pattern of synthesized ZnO

nanoparticles confirms the hexagonal structure. TEM revealed well defined shape of ZnO nanoparticles

with an average crystal size in the order of 20 nm. SEM with EDS authenticated the presence of ZnO.

P-097

GREEN SYNTHESIS OF SILVER NANOPARTICLES USING AQUEOUS EXTRACT OF A MEDICINAL PLANT AND THEIR ANTIBACTERIAL ACTIVITY

V. P. Camargo Pérez1,a, R. Álvarez García2,b, M.A. Hernández- Pérez3,c, M. A. Flores-González1,d, M. Villanueva-Ibáñez 1,e

1 Nanotecnología y Sistemas Inteligentes- Universidad Politécnica de Pachuca Carr. Pachuca-Cd. Sahagún km 20, Rancho Luna, Ex-Hacienda de Santa Bárbara. Zempoala, Hidalgo. CP. 42830. MEXICO

2 Departamento de Biotecnología- Universidad Politécnica de Pachuca Carr. Pachuca-Cd. Sahagún km 20, Rancho Luna, Ex-Hacienda de Santa Bárbara. Zempoala, Hidalgo. CP. 42830. MEXICO

3 Escuela Superior de Ingeniería Química e Industrias Extractivas- Instituto Politécnico Nacional, CP 07738, D.F., MEXICO

[email protected], [email protected], [email protected], [email protected], [email protected],

Keywords: Silver nanoparticles, green synthesis, medicinal plant.

Syntheses of silver nanoparticles (AgNPs) by various physical and chemical methods have been

actively researched. However, these methods employ toxic chemicals as reducing agents, thus limiting

their application in biological systems. Biological approaches using plant extracts for metal nanoparticle

synthesis have been suggested as an alternative to chemical methods and to obtain nanoparticles with

biomedical compatibility. In this work we propose using an abundantly distributed plant in the state of

Hidalgo (Mexico) used in traditional medicine. The antioxidant contents such as polyphenols, flavonoids

and terpenes can act as reducing agents of metal ions. The effect of silver nitrate concentration and the

volume of plant extract in the synthesis were studied. Silver nanoparticles were characterized by UV-Vis

spectrophotometry, Fourier transform infrared spectroscopy (FT-IR) and Scanning Electron Microscopy.


106

The silver nanoparticles are spherical aggregates of size approximately 30 nm. The AgNPs synthesized in

this process were found to have efficient antibacterial activity against pathogenic bacteria such as

Staphylococcus aureus and Escherichia coli.

P-098

SYNTHESIS AND OPTICAL PROPERTIES OF ZnS QUANTUM DOTS DOPED WITH TRANSITION METALS IN AQUEOUS SOLUTION

Beltrán-Mattar, E.I. a, Tirado-Guízar, A.b Pina-Luis, G.E.* c

Centro de Graduados e Investigación. Instituto Tecnológico de Tijuana. Apdo. Postal 1166. Tijuana, B. C. 22000, México.

a [email protected], b [email protected], c [email protected]

Keywords: Quantum dots, dopped, ddots, functionalized

The quantum dots (QDs) are nanocrystalline semiconductors with optical and electrical properties

that are different than the corresponding bulk material, such as high photostability, high luminescent

efficiency, wavelength dependent on the size and narrow emission bands. The surface properties of QDs

are closely associated with dramatic changes in their optical properties. This characteristic offers many

opportunities to detect several specific analytes. Thus, the functionalized QDs have become one of the

most important fluorescent probes for the detection of a large number of analytes including ions, small

molecules and biomacromolecules.The QDs are usually formed by combinations of the elements of group

IIB and VIA such as CdSe, CdTe, CdS, ZnSe, ZnS, etc.. Among this, the ZnS QDs doped with transition

metals (d-dots) are presented as a lower toxicity option than the QDs of tellurides and/or selenides.Here

we reported a systematic study of the synthesis of ZnS d-dots functionalized with MPA and doped with

different atomic percentages of transition metals (from 0 to 12%) such as cadmium and manganese. The

effect of Cd:QD and Mn:QD molar ratios and pH on the reaction were studied in order to achieve better

quality QDs. The influence of these parameters in the fluorescence properties of the QDs was established.

The corresponding QDs were obtained in simultaneous reactions with different doping concentrations in

oxygen-free water solution that was previously purged under argon for 15 minutes, at room temperature

with a 1:1 molar ratio of ZnS. Finally, MPA was added and the sample is kept under stirring during 20

hours. The synthesis method used to obtain these nanoparticles is simple and has advantages over other

methods previously reported. These materials do not require a shell or high temperature reactions with

pyrophoric ligands and have excellent characteristics for use as sensors or in vivo imaging systems.

P-099


107

THERMALLY INDUCED SPIN POLARIZATION IN RASHBA AND DRESSELHAUS SPIN-ORBIT COUPLED SYSTEMS

Priscilla E. Iglesias Vázquez1,a and Jesús A. Maytorena Córdova2,b

1 Posgrado en Física de Materiales, CICESE-UNAM. Ensenada, B.C., México.

2 Centro de Nanociencias y Nanotecnología, UNAM. Ensenada, B.C., México.

a [email protected], [email protected]

Keywords: Spin-orbit interaction, spin caloritronics, spin polarization

The new field of spin caloritronics focuses on the interaction of the spin degree of freedom whit

temperature gradients. Low-dimensional electron systems with spin-orbit interaction (SOI) show a variety

of interesting effects arising from the coupling between charge and spin. In this class of systems the

dominant spin-orbit contribution are the Rashba and Dresselhaus couplings. It is well known that the

electric current in a system with SOI can induce a spin polarization of conduction electrons. This

phenomenon has been studied theoretically and experimentally in various systems exhibiting SOI. More

recently, it has been proposed that a spin polarization density can be induced by a temperature gradient in

a two-dimensional electron gas (2DEG) with Rashba SOI. In this work we investigate the thermally

induced spin polarization in a 2DEG for a general SOI within the linear response theory. The cases of

Rashba and Dresselhaus spin-orbit coupling of a sample grown in the main crystallographic directions are

considered.This work was supported from DGAPA-PAPIIT UNAM under Grants Nos. IN112012,

IN111013 and CONACyT-México.

P-100

SYNTHESIS AND EFFECT OF UREA CONTAIN NANOSPHERES IN CULTURE HYDROPONIC LETTUCE (LACTUCA SATIVA)

Aleana Ledezma Delgadillo1,a, Eduardo San Martin Martínez 2b

1,2 Centro de Investigación y Ciencia Aplicada en Tecnología Avanzada, Instituto Politécnico Nacional, Legaria 694 colonia Irrigación, deleg. Miguel Hidalgo, Distrito Federal, 11700, México


Keywords: Nanotechnology, biopolymers, chitosan, fertilizers

In this project it is nanoencapsulated Urea (NH2-CO-NH2) in nanospheres and to study the

growing effects in a lettuce hydroponic cultivars and to compare effects between a conventional fertilizer

and Urea nanocapsules synthesized with Chitosan (QS) and Methacrilyc Acid (MMA) It was done a data

fractional factorial design considering significant reaction parameters, then it was obtained that the main

parameters would be temperature and the QS concentration. Afterwards it was done a central composite


108

design which indicated that the appropriate synthesis reaction conditions would be 0.01% QS and 0.59%

MMA with a R2 = 0.83 to obtain a nanoparticle size of about 110nm +/-10nm, it was concluded then that

the less were the QS concentration the bigger the particle size would be. By employing FTIR spectrums it

was found the presence of a characteristic peak at 154 cm-1, associated to the presence of an Amide

functional group, which then represents the reaction between the precursors employed and the

composition looked for. Also, by employing electronic microscopy, it was observed a nanoparticle size,

without employing Urea, of about 50nm in a spherical shape. The nanoparticles size, with Urea, was

about 80-100nm.Besides it was chosen the hydroponic cultivars to evaluate the urea nanoparticles effect

in the lettuce growing because of the control and production advantages associated to the hydroponic

systems. In a first French lettuce cultivar fertilized with the urea nanocapsules it was observed that

nanocapsules amount employed was not enough effective for an accurate lettuce growing, it was then

done a second cultivar, in which the leave number, aerial lettuce height and the root length were similar to

those fertilized with conventional products, except for the aerial lettuce weight, probably due to a not

completely effective root urea nanocapsules absortion or an antagonism effect between the Potassium and

Nitrogen precursors.

P-101

STABILITY OF THE METALLIC SPECIES RESULTING OF THE THERMAL REDUCTION OF BIMETALLIC Cu2+-Ag+ SYSTEM EXCHANGED ON NATURAL CLINOPTILOLITE

Inocente Rodríguez-Iznaga1,a, Felipe Castillón Barraza2,b, and Vitalii Petranovskii2,c

1 Instituto de Ciencias y Tecnología de Materiales (IMRE) – Universidad de La Habana. Zapata y G, s/n La Habana 10400. Cuba.

2 Departamento de Nanocatálisis, Centro de Nanociencias y Nanotecnología (CNyN) – Universidad Nacional Autónoma de México. Carretera Tijuana-Ensenada, Km 107. Ensenada, B.C. México.


Keywords: Natural zeolite, Clinoptilolite, Reduction, Nanoparticles, Copper, Silver.

The decay pattern of metal nanospecies prepared by the thermal reduction in hydrogen flow of

Cu2+-Ag+ bimetallic system, exchanged in natural clinoptilolite from Tasajeras deposit, Cuba, was

studied. The aim was to analyze the influence of second metal on the stability of the reduced species after

a long time aging in ambient conditions. Comparison of observed degree of declining of the features

typical for the presence of these species in the UV-Vis diffuse reflectance spectra is used as a measure of

their stability. Analysis of XRD data for metal nanoparticles formed at high temperature of reduction

coincide with the conclusions made from UV-Vis spectra data. Pattern of decomposition of freshly

reduced nanospecies include complete oxidation of metals to ionic species or formation of nanoparticles


109

of smaller size and few-atomic clusters (Ag8 and Cun) as intermediate steps before final complete

oxidation. Stability of the nanoparticles, possessing plasmon peak in the UV-Vis spectra increases with

temperature of reduction. They are much more stable in the samples reduced at 450oC compared with the

same materials reduced at 150oC, and they are absent in the samples reduced under lower temperatures. In

the same time stability is much higher for bimetallic system, comparing with the same zeolite exchanged

with Cu2+-only and reduced in equal conditions. This work was supported by CONACYT, Mexico,

through the Project 102907 and UNAM-PAPIIT through the grant IN110713.

P-102

INFLUENCE OF LEWIS ACIDITY ON THE NANOPARTICLES SUPPORTED IN ZEOLITES

Elena Smolentseva1,a, Vitalii Petranovskii1,b

1 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, km.107 carr. Tijuana a Ensenada, C.P. 22860, Ensenada, B.C., México


Keywords: Nanoparticles, Lewis acidity, zeolites, metal cations

Zeolites, modified with metal cations, have been extensively studied during the last two decades,

because of their wide application in different technologically important fields such as catalysis, adsorption

and gas separation. Main attention was paid mostly to monometallic systems. At the same time, a growing

number of fragmented observations about significant impact of the zeolite matrix cationic composition on

the behavior of the target metal was accumulated. Various forms of reduced species and a significant

change in the stability of formed nanoparticles were observed in binary and ternary systems. The aim of

this work was to summarize the observed influence of second cation, such as proton, sodium, iron, nickel,

zinc etc. on the stabilization of copper, silver and gold nanoparticles supported in the voids of zeolite

matrixes, such as mordenite, clinoptilolite and faujasite. Known to be a "Lewis acid", these cations

influence the donor-acceptor interaction, and in this way change the properties of formed coinage metal

nanospecies and their chemical activity (i.e. stability). Selected zeolites, those usually are supplied in

sodium or hydrogen forms, were previously modified with iron, nickel or zinc cations using aqueous

solutions of corresponding nitrates. Secondarily copper, silver, or gold were exchanged on these

pretreated samples. Prepared bimetallic forms were thermally treated in hydrogen or in air, and obtained

metal nanospecies were characterized with UV-Visible spectroscopy, XRD, TEM and SEM. It was found

that the formation and stabilization of nanoparticles proceeds differently, depending on the type of zeolite,

and the nature and strength of Lewis acidity of cations. Comparison of these bimetallic systems will be

done putting attention on a quantitative scale for Lewis acidity and the concept of "hard and soft Lewis


110

acids and bases". The authors thank to E. Flores, P. Casillas, I. Gradilla, F. Ruiz, E. Aparicio, M. Sainz

and J. Peralta for their kind technical support in this work. This work was financially supported by

CONACYT, Mexico, through the Project 102907 and UNAM-PAPIIT through the grant IN110713,

respectively and SENER-CONACYT through the grant 117373.

P-103

SYNTHESIS OF Al2O3 AND TiO2 NANOTUBES BY ATOMIC LAYER DEPOSITION USING CARBON NANOTUBES AS TEMPLATES

F. Muñoz-Muñoz1a, H. Tiznado1b, D. Domínguez1c, J. Romo-Herrera1d, G. Soto1e, O.E. Contreras1f and G. Alonso1g.

1Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada, C.P 22860, Ensenada B.C. México

[email protected], [email protected], [email protected] [email protected], [email protected], f [email protected], [email protected].

Keywords: Vitreous metal nanotubes; Atomic layer deposition; Templates

The remarkable advance of electronic, optoelectronic and electrochemical devices has promoted

the necessity of develop nanostructures with specific characteristics related to the structure and chemical

composition such as tubes, rods or wires. In this field, carbon nanotubes (CNTs) are highlighted by their

extensive adaptation in various technological devices. However, other substances have been successfully

attached on the surface of CNTs in order to generate new functionalities or to improve significantly their

physicochemical properties, such as low permeability, high thermal conductivity and dielectric constant,

etc. The combination of CNTs with other materials may be proven to be key components in the next

generation of catalysts, reinforced nanofibers, sensors, electronic, semiconductor, nanooptical and data

storage/processing devices. For this reason, recent studies have focused on the use of CNTs as templates

for preparing metal oxide nanostructures using different methodologies. In this work is presented the

preparation of aluminum (Al2O3) and titanium (TiO2) vitreous oxides nanotubes by atomic layer

deposition (ALD) technology using CNTs as templates, which are subsequently removed by calcination

in air using a slow temperature ramp. The vitreous nanotubes were observed by Transmission Electron

Microscopy (TEM); chemical composition was evaluated by X-ray photoelectron spectroscopy (XPS);

and thermal properties were analyzed by thermo gravimetric analysis (TGA). The purpose of this study

was to obtain vitreous metal nanotubes with an excellent control in thickness and demonstrate that ALD is

a suitable technique for the coating of nanostructures. This work was supported by DGAPA-UNAM

IN114209-3 and CONACyT project 83275, Mexico.

P-104


111

SYNTHESIS OF DENDRIMERS OF GENERATION ZERO (G0 ) WITH ESTER GROUPS

Berenice Vargas1,2a, A. Olivas1b and D. Madrigal2c

1 CNyN, UNAM, Ensenada, B. C. México.

2 ITT-CG, Tijuana, B. C. México

a [email protected], [email protected], [email protected]

Keywords: Dendrímer, synthesis divergent, ester.

The n-butyl acrylate is used mainly in the manufacture of synthetic fibers and polymer

dispersions which are employed for the manufacture of leather and adhesives. It is also used in the

preparation of polymers and macromolecules.1 The globular dendrimer2 are prepared through convergent

or divergent iterative synthesis was recently reported in the literature.3 some important biomedical

applications for dendrimers, with emphasis on their chemical composition and typology has influenced

the biocompatibility and pharmacokinetic profile, some of dendrimers most used in biomedicine

containing groups polyamidoamine, polyamines, polyamides, polyarylethers, polyesters, carbohydrates

and DNA in its structure.In this work, where the divergent synthesis is used as a core to which is made

pentaerythritol with butyl acrylate in order to produce dendrimers of generation zero (G0), with groups

butyl ester in the periphery. The low nucleophilicity of oxygen, made difficult by adding pentaerythritol

acrylate double bond was necessary to test various reaction conditions, using various solvents and

temperature control. The complicating factor was much polymerization obtaining products.And a mixture

of compounds according to the evaluation in thin plate where observed the formation of three products

that probably correspond to G0 dendrimers disubstituted, tri substituted and tetra substituted was

obtained. Infrared spectra of the obtained results are in agreement with those expected for the ester where

obtained dendrimeric.

P-105

SCR OF NO WITH C3H6/CO OVER BIMETALLIC SYSTEM (AG/FE) SUPPORTED IN ZEOLITES: EFFECT OF TYPE STRUCTURE

P. Sánchez-Lopez1,a, R. Obeso-Estrella1,b, S. Miridonov2,c, S. Fuentes3,d, A. Simakov3,e, F. F. Castillón Barraza3,f and V. Petranovskii3,g

1 Posgrado en Ciencia e Ingeniería de Materiales de la Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Apdo. Postal 14, C.P. 22800, Ensenada, B.C., México

2 Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de Ensenada, C. P. 22860, Ensenada, B. C., México

3 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Apdo. Postal 14, C.P. 22800, Ensenada, B.C., México


112

[email protected], breneoe@cnyn,unam.mx, [email protected], [email protected], [email protected], [email protected], [email protected]

Keywords: Zeolites, mordenite, ferrierite, ion exchange, SCR of NO.

Mordenite and ferrierite type zeolites with SiO2/Al2O3 molar ratio of 13 and 20, respectively,

were selected to prepare binary systems of Ag:Fe/zeolite. Ag and Fe ions were introduced in zeolite

matrices by ion exchange from aqueous solutions of FeSO4 and AgNO3 0.03 N concentration, varying the

Ag/Fe ratio and the order of introduction of the cations. The samples were characterized by EDS, XRD,

BET, UV-Vis, TPD, and evaluated in the selective catalytic reduction (SCR) of NO with a mixture of

C3H6/CO in an oxidizing atmosphere. The results revealed that both the type of zeolite structure and the

order of cation exchange influenced the catalytic activity. It was observed that the catalysts supported on

mordenite were more active and effective for NO conversion referring to those supported on ferrierite.

Authors acknowledge assistance of E. Aparicio, I. Gradilla, J. Peralta and E. Flores, and support from

CONACYT 102907 and UNAM-PAPIIT IN110713 grants.

P-106

GRAPHENE NANOCOMPOSITES FOR REMOVAL OF OPPS IN AQUEOUS MEDIA

Dhananjay Tripathi 1, a, Supriy Verma 2, b and D. K. Tiwari 3, c

1 Institute of Environment & Sustainable Development, Banaras Hindu University, Varanasi-221005, India.

2 Department of Chemistry, Banaras Hindu University, Varanasi-221005, India.

3 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, B.C. 22800, México.

a [email protected] , b [email protected], c [email protected]

Keywords: Adsorption, Chlorpyrifos, Dimethoate, Graphene, Organophosphorous Pesticides, Phorate.

Organophosphorus pesticides (OPPs) are one of the most widely used classes of agricultural

Pesticides introduced in 1970s. This study was carried out to explore the use of graphene oxide

nanocomposite for the removal of organophosphorous pesticides (OPPs) like chlorpyrifos, dimethoate

and phorate from water under different conditions. They belong to the organophosphate group which are

second generation pesticides developed as substitutes to organochlorinated pesticides. In order to

delineate the removal mechanism and to comprehend the observed uptake capacity, an analysis using

first-principles pseudopotential-based density functional theory was carried out. The observed adsorption


113

capacities of chlorpyrifos, dimethoate and phorate are as high as 1100, 700, and 1400 mg/g respectively.

Adsorption is found to be insensitive to pH or background ions. The adsorbent is reusable and can be

applied in the field. The analysis shows that the interaction between graphene nanocomposites, water and

pesticides is found to be stronger compared with the direct interaction of graphene nanocomposites and

pesticides.

P-107

WO3 TOXICITY ON SOIL BACTERIA

Marcela Ovalle1a, Eurydice C. Arroyo1, Luis Enríquez2, Amelia Olivas1b

1 Centro de Nanociencias y Nanotecnología-Universidad Nacional Autónoma de México

2 Laboratorio de Ecología Molecular, Facultad de Ciencias Marinas-Universidad Autónoma de Baja California, C.P. 22800 Ensenada, B. C., México.

a [email protected], b [email protected]

Keywords: WO3 microparticles, toxicity.

This work studies the effect of Tungsten oxide on the on the growth of the bacteria Tetrasphaera

duodecadis. To this effect, commercial WO3 microparticles were added into the liquid and solid culture

media at different concentrations. A growth curve was elaborated based on the hourly samples taken from

the cellular suspension and the colony-forming units (CFU) were counted. The growth curve was as well,

contrasted to the measurement of the optic density of the suspension at 620 nm. The results obtained were

compared to the bacteria growth curve in the standard culture media. It was demonstrated that the WO3

microparticles do not present any kind of toxicity in the bacteria growing; hence some biological

applications of this particles are proposed.

P-108

ELABORATION OF CONJUGATED OF MULTIPLE WALL CARBON NANOTUBES AND PROTEINS

Vásquez Martínez C. A.1a, Aguilar Vázquez J.1b, López Barroso J.1c, Pérez-Campos E.1d, Gil-Gallegos M.1e, Gochi Ponce Y.1f, Pérez Santiago A. D.1g

1 Instituto Tecnológico de Oaxaca, Av. Víctor Bravo Ahuja No. 125 Esq. Calz. Tecnológico, Oaxaca, Oax. México. C.P. 68030.

a [email protected], [email protected],[email protected], [email protected], [email protected], [email protected],

[email protected]

Keywords: carbon nanotubes, lectins, functionalization, bifunctional molecule.


114

The carbon nanotubes are novel structures produced artificially, which have unusual physical

properties. Nowadays, these properties are being used in biology. However, its nature obstructs the

incorporation of certain functional groups. In order to solve this problem, some different methodologies

have been developed, whose objective is changing the superficial properties of the CNT by submitting

them to an acid environment (covalent interaction) or to an hydrophobic interaction (non-covalent

interaction), to get a better compatibility in watery environment and in organic solvents. This process is

known as “functionalization” and it could be present in the extremities, on the cylindrical wall or inside

the nanoparticle. The CNT functionalized have a particular potential for the transportation, release and

delivery of biologically active molecules, and for the conjugation with proteins as lectins, which have a

very high capacity for recognizing carbohydrates on cell surface, and, by this way, for interacting with

other cells. In this work, a non-covalent functionalization of a multiple wall CNT, with Con A and

Phaseolus lunatus, var. Silvester lectins, was performed using a bifunctional molecule. The lectins were

marked with FITC and, before the conjugation an agglutination tests, protein concentration and

agglutinant activity inhibition were found in them. For verifying the functionalization, a fluorescence

microscopy, an infrared spectroscopy and a Raman were realized. The spectrum obtained by infrared and

Raman indicated the presence of functional groups in the nanotube surface.

P-109

ENCAPSIDATION OF siRNA BY THE CCMV CAPSID PROTEINS

J. N. Zamudio-Ocadiz, 1,2,a R. Vazquez-Duhalt2,b and R. D. Cadena-Nava.2,c

1 Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, B.C, México.

2 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México. Ensenada, B.C, México.


Keywords: CCMV, siRNA, encapsidation, electrophoresis, TEM.

The Cowpea Chlorotic Mottle Virus (CCMV) is a single-stranded RNA (ssRNA) icosahedral

virus, which under certain conditions of pH and ionic strength have been disassembled and reassembled

in vitro. In this work, we show the encapsidation of small interfering RNA (siRNA) with the capsid

proteins of CCMV. The siRNA is a double-stranded RNA (dsRNA) molecule with 21 base pairs of

length, the most notable role of siRNA is that can suppress the expression of a target gene with

complementary nucleotide sequence. Synthesis of siRNA molecules was done in vitro, with a T7 RNA

polymerase based system. The siRNA used in this work corresponds to a Renilla luciferase protein. Gel

electrophoresis was performed to determine the synthesis of siRNA and the assembled nanoparticles were


115

analyzed by Transmission Electron Microscopy (TEM). We observed spherical and tubular capsids with

diameters of 21 and 16 nm respectively, we observed large and short tubes. We propose the use of

protein shells from the Cowpea Chlorotic Mottle Virus (CCMV) to protect and delivery siRNA to target

cells. The results obtained in this work could be used to improve the siRNA-based therapies.

P-110

LACCASE FROM CORIOLOPSIS GALLICA IMMOBILIZED ON NANOSTRUCTURED SUPPORTS

Darío J. Cruz Ríos, José A. Tejeda Rodríguez, David Shimomoto Sánchez and Sergio A. Águila Puentes.

Centro de Nanociencias y Nanotecnología, UNAM, Ensenada B.C México

[email protected],[email protected],[email protected],[email protected].

Keywords: laccase, immobilization, nanostructured support

Laccase is an oxidoreductase enzyme in which the active site has Cu2+ atoms. It is divided into

three sites, according to data of electron paramagnetic resonance (EPR) T1, T2 and T3. T1 site (1 atom of

Cu+) has a function to subtract electrons and protons from substrates and transfer them to the site T2/T3

(3 Cu2+) where O2 is reduced to H2O, as shown in Figure 1. This enzyme was immobilized on mesoporous

supports (SBA-15, MCF, and MSU-F) and was characterized. The catalytic activity was determined and

compared with the free enzyme. The effect of pH, hydrothermal stability and solvent (acetonitrile) was

also studied. To be able to study the hydrothermal stability of the free and immobilized enzyme, it

remained in boiling point water bath (100 ºC) with increasing time and the residual activity was

determined. The effect of pH was studied in the range from 4.5 to 10 and the solvent effect was

determined in the range of 10 to 80%. The results showed that the immobilized enzyme in nanostructured

supports has a catalyst stability improvement compared with the free enzyme.

P-111

EXPERIMENTAL EVIDENCE OF THE NON-TRANSMISSION RANGE ENLARGEMENT IN PHONONIC HETEROSTRUCTURES

B. Manzanares-Martinez1,a, J. Manzanares-Martinez2,b

1 Departamento de Fisica, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo 83190, Mexico

2 Departamento de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190, Mexico


Keywords: Phononic crystal, elastic wave, longitudinal, transverse


116

In this work we present experimental evidence of the enlargement of the non-transmission range

in one-dimensional phononic crystal heterostructures. Heterostructures are composed by a tandem of

different phononic crystal lattices. The constituent phononic crystal lattices have been properly chosen so

that their band gaps overlap each other to obtain a giant stop band. Heterostructures consisting of a

periodic arrangement of aluminum and epoxy layers were fabricated and characterized. We have designed

giant stop bands in the range of MHz obtaining a good agreement between theoretical and experimental

results.

P-112

OMNIDIRECTIONAL MIRROR BASED ON BRAGG STACKS WITH A PERIODIC GAIN-LOSS MODULATION

J. Manzanares-Martinez1,a, B. Manzanares-Martinez2,b

1 Departamento de Investigacion en Fisica, Universidad de Sonora,Apartado Postal 5-088, Hermosillo, Sonora 83190, Mexico

2 Departamento de Fisica, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo 83190, Mexico


Keywords: Omnidirectional Mirror, gain-loss, Bragg Stack

In this work we demonstrate that a Bragg Stack with a periodic gain-loss modulation can function

as an Omnidirectional Mirror (OM) with complete reflection at any angle of incidence irrespective of the

light polarization. The Bragg Stack is composed by the periodic variation of two layers with the same

value of the real part of the refractive index and a periodic modulation in the imaginary part. The origin of

the band gaps is due to the interference of complex waves with propagating and evanescent fields in each

layer. It is found that the band gaps are wider as the contrast increases. We have found the ambient

conditions to obtain an OM considering an auxiliary medium n external to the Bragg Stack.

P-113

SYNTHESIS OF BIMODAL MESOSTRUCTURED KIT-6 MATERIALS.

Torres-Otáñez G.1,a, Díaz de León J. N.1,b, T. Zepeda1,c, S. Fuentes1,d

1 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Ensenada B.C., México


Keywords: Mesostructured; KIT-6; bimodal.


117

Siliceous mesoporous materials have attracted great interest because of their high surface area

and ordered mesoporous structures. This kind of materials has been used as a support of several catalysts

due to the easy dispersion of active phases. The impregnation density can be increased in comparison to

the typical supports as alumina kind. The structured porosity allows to obtain a better diffusion of the

reactants into the catalyst, increasing at the same time the effectiveness factor. The described above has a

direct impact in catalytic activity and selectivity. In this work, synthesis of 2D siliceous nanomaterials

(2D-SM) has been done. The 2D-SM was characterized by N2 absorption-desorption isotherms, X-ray

diffraction (XRD) and high resolution electron microscopy. Specific surface area (Sa) for the 2D-SM

sample was 813 m2g−1, the pore volume (Pv) 0.65 cm3 g-1 and a bimodal pore size distribution centered

at 39 Å and 60 Å. This results have shown that this material have similar textural properties in

comparison to that reported synthetized with the same structure directing agent and in the range of

standard siliceous materials (SBA, KIT-6 or MCM). Also, XRD analysis showed a low-angle peak at 0.5

2 degrees, characteristic of a mesostructured material. The HRTEM micrographs have exhibited

hexagonal porosity arrangement as it has been anticipated. Nevertheless, unexpected semi concentric or

multiwall zones and uniform channels were observed. Fully characterization is in progress to get insight

of this materials in order to use it as a hydrodesulfurization support catalyst.

P-114

SYNTHESIS AND CHARACTERIZATION OF COPPER TELLURIDE (CUTE) BY ION EXCHANGE

O. Arellano-Tanori1,2,3,a, R. Godoy-Rosas1,4,f , H.A.Pineda-Leon1,4,c, E. Fernadez-Diaz1,2,c, E. Chavez-Mendiola1,2,e, T. Mendivil-Reynoso1,5,6,b ,R.Ochoa-Landin6,g, S.J. Castillo1,h







[email protected], [email protected], [email protected], [email protected] [email protected], [email protected], [email protected],

[email protected]


118

Keywords: Copper telluride, Photometry XPS, FTIR, X-ray (EDS), Bandgap, Crystalline orthorhombic,

Rongalite, Tellurium ions

The method used for the synthesis of copper telluride is mainly based on chemical reaction

precursors containing tellurium and copper. Copper nitrate was used to produce copper, for tellurium

rongalite tellurium ions. The absorption spectrum for the sample of copper telluride displays

corresponding values for direct bandgap 3.01 eV and 2.91 eV indirect bandgap at room temperature.

FTIR studies were conducted corresponding to spectrum characteristic absorption peaks for copper

telluride 530 cm-1 which identifies copper nanoparticles. The Raman study sample exhibits bands at 411,

438 and 471 cm-1 in tellurate hydrate copper (CuTeO3 2H2O). XPS copper telluride, shows the peaks

for Te 3d3 and Te 3d5 corresponding to the value of binding energy of 575.5 eV, which identifies

tellurium ions; Te 3d region shows that the valence of Te is -2, while the Cu 3p valence region show for

copper 1. In the sample of copper telluride TEM, one can observe an aspect of a well-defined nano-

caterpillar. Electron diffraction shows interplanar distance 3.514 Å and d = 3.566 Å very similar and

elucidated the crystal structure, these distances are typical for a crystalline compound CuTe orthorhombic

(JCPDS # 22-0252), the study is achieved by magnifying the region until the 10 nm (400 000 extensions).

P-115

PREPARATION OF NANO-STRUCTURED POWDER OF COBALT TELLURIDE (COTE2) BY ION EXCHANGE IN CHEMICAL REACTIONS

O. Arellano-Tanori1,2,3,a, H.A.Pineda-Leon1,4,c, E. Fernadez-Diaz1,2,d, E. Chavez-Mendiola1,2,e, R. Godoy-Rosas1,4,f, T. Mendivil-Reynoso1,5,b, R.Ochoa-Landin6,g, S.J. Castillo1,h








[email protected]


119

Keywords: Nanoparticles, Cobalt telluride, Characterizations, Ion-Exchange

By using Cobalt Chloride and Tellurium ions in rongalite as precursors in the chemical reactions

Cobalt telluride was obtained in nano structured powder and characterized, obtaining this results: UV -Vis

direct and indirect bandgap 1.7 eV and 2.32 respectively. IR The sample was mixed with KBr pellets for

the reading of the spectrum, it can be seen that the absorption peaks at FTIR for cobalt telluride shows

absorption peaks at 3446 and 1600 cm–1 and at 524 cm - 1 corresponds to the vibrations of Co-O bonds,

the existence of this peak is ground for determining formation of cobalt telluride nanoparticles. Cobalt

telluride Raman spectrum shows frequencies that coincide with those in references listed. XPS spectrum

for cobalt telluride compound includes two binding energies corresponding to tellurium Te 3d5/2 and Te

3d3/2, and cobalt 2 p/2 and 2 p1/2 for features shown. TEM the interplanar distance obtained were d =

3.28 Å and d = 1.97 Å. These distances are characteristic of a corresponding orthorhombic structure

CoTe2 whose crystallographic planes are the [001] and [220] (JCPDS # 65-2572)

P-116

SYNTHESIS AND CHARACTERIZATION OF STRONTIUM SELENIDE (SrSe) CHEMICAL REACTION BY USING ION NITRATE COPPER AND SELENIUM IN RONGALITE

O. Arellano-Tanori1,2,3,a, T. Mendivil-Reynoso1,4,6,b, H.A.Pineda-Leon1,4,c, E. Fernadez-Diaz1,2,d, E. Chavez-Mendiola1,2,e, R. Godoy-Rosas1,4,f, R.Ochoa-Landin6,g, S.J. Castillo1,h









[email protected]

Keywords: Strontium selenide, Rongalite, Semiconductor bandgap, Optical absorption


120

SrSe is obtained using a chemical reaction by ion-exchange method, which are used with

strontium and selenium precursors. Characterization of optical absorption in this work is similar to that

obtained in a previously reported mathematical model, the direct band gap that 2.9 was found both eV and

the indirect band gap that was 4.5 eV. The FTIR spectroscopy which shows this research for the seleniuro

of strontium, coincides with data previously reported, which validates the obtaining of the SrSe, in the

infrared spectrum, appear the same for bands at 3446 / 1600 cm-1 for the strontium selenide, and these

correspond to the O-H vibration and H -O - H, bending vibration respectively. To use RAMAN

spectroscopy to analyze SrSe, frequencies that characterize it, we identified was observed the peak

corresponding to 192 cm-1, which is the SrSe2. Was also performed studies of TEM sample seleniuro of

strontium with the purpose of knowing its morphology, there are no defined arrangements, particles

agglomerated to obtaining a single distance interplanar for this compound, which it can be concluded that

it corresponds to a cubic array, the distance interplanar of this compound is d = 3.27 A, which

corresponds to crystallographic plane [200] JCPDS # 10-0182).

P-117

SYNTHESIS AND CHARACTERIZATION OF TELLURIDE STRONTIUM (SrTe2) BY CHEMICAL BATH, AND USING STRONTIUM CHLORIDE ION IN RONGALITE TELLURIUM.

O. Arellano-Tanori1,2,3,a, T. Mendivil-Reynoso1,4,6,b, H.A.Pineda-Leon1,4,c, E. Fernadez-Diaz1,2,d, E. Chavez-Mendiola1,2,e, R. Godoy-Rosas1,4,f, R.Ochoa-Landin6,g, S.J. Castillo1,h








[email protected]

Keywords: Telluride Strontium, Rongalite, Semiconductors, Bandgap, Optical absorption


121

This work is a method of obtaining the Telluride strontium, this work reports few related

investigations in which the Telluride strontium was synthesized and they are part of this investigation,

since them, validate the results obtained in this document. New method of synthesis, which are obtained

satisfactory results that are similar to those reported in other research is proposed. The method used for

the synthesis of Telluride strontium is bath chemical based primarily on precursors containing tellurium

and strontium. Shows the characterization of optical absorption where it was determined a indirect

bandgap of 1 eV and 3.3 eV direct bandgap. Subsequently be characterized the tellurium of strontium

with the FTIR absorption peaks were observed approximately at 3446 and 1600 cm - 1 to metallic

tellurium, which correspond to the o-h vibration and vibration of bending h-o - H, respectively, this is due

to the absorption of H2O in these sample. The following characterization was RAMAN spectroscopy,

yielding approximately 158 cm-1, which is attributed to the binaries of tellurium compounds of strontium.

P-118

GOLD NANOPARTICLES DEPOSITED BY DP AND IE: THE ROLE OF METHOD NATURE

Eunice Vargas1,a , Miguel Estrada2,b, Elena Smoletseva3,c, Felipe Castillón3,d, Sergio Fuentes3,e, Andrey Simakov3,f

1 Facultad de Ingeniería, Arquitectura y Diseño, UABC, Ensenada, B.C., México

2 Posgrado en Física de Materiales, CICESE, Ensenada, B.C., México

3 Centro de Nanociencias y Nanotecnología, UNAM, Ensenada, B.C., México



Keywords: Gold NPs, Gold catalysts, Deposition-Precipitation, Ion-Exchange.

Owing to the moderate adsorption of at least one of reactants (for example, CO) on the edges and corners

of Au nanoparticles (NPs) and to the activation of the counter reactant (for example, O2) at the perimeter

interface with the supports, supported Au nanoparticle catalysts exhibit unique and practically useful

catalytic properties at relatively low temperature below 473K. The aim of this work was a comparative

analysis of gold catalysts supported on alumina, synthesized by two different methods. Catalysts (Au (3%

wt)/Al2O3 DP and Au (1% wt)/Al2O3 IE) were synthesized by Deposition-Precipitation of gold

precursor with urea and Ion exchange with Au [NH3]4(NO3)3, respectively. The dynamic of gold species

activation under sample thermal treatment was characterized by UV-Vis and FTIR in situ in a flow

reactor equipped by valves with high speed accessory and mass spectrometer. Catalysts were tested on

CO oxidation and NO reduction. It was found that the average particle size was strongly affected by the

gold deposition method. There are two consequent steps of a gold NPs formation for Au/Al2O3 DP


122

sample: 1) slow formation of gold nuclei due to thermal decomposition of gold hydroxide; 2) fast

formation of gold NPs via agglomeration of gold nuclei and gold hydroxide reduction with hydrogen. On

Au/Al2O3 IE sample the gold NPs were formed due to the thermal decomposition of gold complex. The

catalytic behavior is determined by the nature of gold species formed. Acknowledgments:The authors

thank to E. Flores, P. Casillas, V. García, F. Ruiz, E. Aparicio, M. Sainz and J. Peralta for their kind

technical support in this work. This project was supported by DGAPA–PAPIIT (UNAM, Mexico) and

CONACyT (Mexico) through grants 203813 and 179619, respectively. E. Vargas is grateful for CNyN

for grants IMPULSA UNAM and CONACyT (Project 50547).

P-119

FUNCTIONALIZATION OF MWCNT WITH HYDROXYMETHYLENE GROUPS AND THE REACTION WITH PHOSPHAZENE

Rubén Rodríguez Jimenez1a, Eduardo Rogel1, Gabriel Alonso Nuñez2 Heriberto Espinoza Gomez1, Ernesto Velez1, Francisco Paraguay Delgado3

1 Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California. Ave. Calzada Universidad 14418 Tijuana, B. C., México, C.p. 22390.

2 Centro de Nanociencias y Nanotecnología de la UNAM, Km. 107 carretera Tijuana-Ensenada, Ensenada B.C., Apdo. postal 356, C.p. 22860

3 Centro de Investigación en materiales Avanzados, Chihuahua, Chi., México, C.P. 31109

a [email protected] , [email protected]

Keywords: MWCNT, Hidroxymethylene, Functionalization, Carbon Nanotubes, Phosphazene.

Technological advances have opened new doors to develop and implement new materials. Of

these technology areas is nanotechnology, with the discovery of macromolecules named carbon

nanotubes, which has unique properties, such as mechanical, electronic, structural, and others.

Functionalization of CNTs improves the chemical and physical properties. This work was made the

functionalization and characterization of CNTs added with CH2OH groups, later reacted with an

inorganic monomer known as phosphazene (Cl6N3P3), for their later characterization. In first place, the

functionalization was carry out by using 30 mg of MWCNT, in a round bottom flask, adding 27 mL of

Methanol and 300 mg of benzoyl peroxide (BPO), which is the reagent that will generate the free radicals

of -CH2OH. Then purified with methanol to remove the unreacted BPO, and the characterized with FT-

IR, Raman Spectra, Mass Spectra, TGA, TEM-EDX. Therefore in this particular work we chose to add an

inorganic molecule the hexachlorocyclotriphosphazene. These molecules have various applications, and

covers areas ranging creating teeth, fire retardant materials, biodegradable materials and fuel cells. They

have determined that phosphazenes, in addition to the areas which are used, there are some of them may


123

even degrade and become less molecular weight molecules which can be incorporated without damaging

the environment, which makes molecules of interest. Therefore the reaction product of this research

enables us to develop new subsequent amendments, to help us change the physical and chemical

properties of nanotubes and their potential applications. Since functionalized nanotube with the-CH2OH

group, is reacted with the HCCTF, each of the reactants are dispersed in anhydrous tetrahydrofuran

(THF), to homogenize the mixture. We used sodium hydride (NaH) in order to form alkoxides, in the

MWCNT-CH2OH and unite the Cl6N3P3 for subsequent characterization by FT-IR, Raman, TEM , SEM

and EDS, TGA and Mass Spectrometry.

P-120

SPHERE PACKING PROBLEM FOR BIMODAL DISTRIBUTION OF PARTICLE SIZES IN MATERIAL ENGINEERING

Larysa Burtseva1,a, Vitalii Petranovskii2,b, Rainier Romero3,c and Benjamin Valdez1,d

1 Engineering Institute of the Autonomous University of Baja California, Mexicali, B. C., Mexico

2 Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Ensenada, B.C., México

3 Polytechnical University of Baja California, Mexicali, B. C., Mexico


Keywords: Sphere; Packing; Bimodal distribution; Packing structure; Computer approach

Random packings of spheres have many reflections in material science. As an example, in

nanotechnology the filling of porous media is modeled as packed arrangements of hard spherical atoms.

Random close packings are studied experimentally, theoretically and by computer modelling, i.e.

performing analysis of intrinsic structure and packing simulations. These simulations are subdivided into

two types. The first is characterized by a kinetic nature and includes sedimentation of spheres into a

randomly packed bed as well as molecular dynamics and Monte Carlo methods. The second type consists

of simulations of the densest packing’s and growth of clusters. Such parameters as the void age and

density, as well as the distribution of the coordination number are calculated. Simulated packings serve as

models for real structures of particles, however, the assumptions that the particles are spheres and these

spheres are monosized are the common simplifications. It means that only the monoatomic nanoparticles

in nanovoids of porous matrices can be modeled. However, real materials include nanoparticles of at least

two components, such as oxides or sulfides, with atoms of two different sizes. The characteristics of the

simulated packings of bimodal particle sets should be at least similar to those of the real structures

investigated. The common parameters have been reported in the literature for bimodal packings. Very

little is known about the intermediate structure when that is a confined space or a cluster growing.


124

Bimodal structures have higher density than unimodal ones. Study of structures with bimodal diameter

distribution produces a wide spectrum of new research problems, meanwhile the reported investigations

are limited to relatively simple packing systems. Optimization of bimodal packing density permits an

interpretation as the Container Loading Problem, an extension of Bin Packing, which is known to be NP-

hard in Computer Sciences. Most existing algorithms are stochastic, and there are no proofs of optimality

when the number of spheres is large. The possible solutions lead to the Computer Geometry simulations,

as well as to Non-linear programming and Voronoy-Dealanau approaches.This work was supported by

CONACYT, Mexico, through the Project 102907 and UNAM-PAPIIT through the grant IN110713.

P-121

LUMINESCENT NANOPARTICLES AS POSSIBLE THERANOSTIC AGENTS: IN-VIVO EVALUATION IN A MOUSE MELANOMA MODEL

González López Sandra Patricia1,a, Fernández Garibay, Xiomara Gislen1,b; Minjares Espinoza, Lizette1,c; Arteaga Cardona, Fernando1,d; Hernández Gutiérrez, Salomón2,e; Palacios Hernández, Teresa1,3,f; Flores Alonso, Juan Carlos4,g; Hirata Flores, Gustavo5,h and Angulo Molina, Aracely1,i.

1 Universidad de las Américas Puebla (UDLAP), México

2 Universidad Panamericana (UP), México

3 Universidad Popular Autónoma del Estado de Puebla (UPAEP), México

4 Centro de Investigaciones Biomédicas de Oriente (CIBIOR, IMSS), México

5 Centro de Nanociencias y Nanotecnología (CNYN-UNAM), México.

[email protected], [email protected], [email protected], d.

[email protected],[email protected],[email protected],g.flores_alonso_jc@hotm

ail.com, h. [email protected], i. [email protected].

Keywords: luminescent nanoparticles, theragnostic agent, murine melanoma model.

There is currently great interest in finding biocompatible luminescent nanomaterials for diagnosis

and treatment of cancer. Materials that can have both uses are called theranostic agents. Luminescent

nanoparticles (Nps*) with biomedical purposes have not been widely studied, however, they have

potential for use as contrast agents and as drug delivery systems. A murine melanoma model was

developed by xenotransplantation of the B16F tumor cell line in BALB/c nude mice. Once the tumor was

established, we evaluated two types of Nps*, Y2O3:Eu and (EuLa)2O3, synthesized by a combustion

method in a Batch reactor. The nanoparticles were i.t. administrated at different doses. The in vivo

presence of the nanoparticles was evaluated by x-rays and ultrasound. Subsequently, histological cross-

sections of the tumor were analyzed by epifluorescence microscopy.The Y2O3:Eu and (EuLa)2O3 Nps*

were detected in the tumor tissue. In the ultrasonogram, an elliptical hyperechoic homogeneous image


125

with regular borders and with posterior acoustic shadow was identified. With x-rays, we observed a

radiodense image with regular borders, especially for Y2O3:Eu. The Nps* resisted the standard treatment

for tissue fixation and embedding in paraffin, which allowed their observation by fluorescence

microscopy. Y2O3:Eu and La2O3:Eu luminescent nanoparticles present good in-vivo photostability,

fundamental properties for real time tracking and monitoring of biological events in the cellular level.

P-122

COBALT SELENIDE PREPARATION BY CHEMICAL EXCHANGE REACTION

O. Arellano-Tanoria,b,c, T. Mendivil-Reynosoa,e,f, H.A.Pineda-Leona,d, E. Fernadez-Diaza,b, E. Chavez-Mendiolaa,b, R. Godoy-Rosasa,d, R.Ochoa-Landinf, S.J. Castilloa

a Departamento de investigación en Física, Universidad de Sonora, Apdo. Postal 5-088 CP 83000, Hermosillo, Sonora, México.

b Instituto Tecnologico de Hermosillo, Av. Tecnologico s/n Col. Sahuaro, CP 83170, Hermosillo, Sonora, Mexico.

c Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Sonora Norte, Blvd. Enrique Mazon Lopez No.965, CP 8300, Hermosillo, Sonora, Mexico.

d Departamento de Matemáticas, Universidad de Sonora, Luis Donaldo Colosio y Rosales S/N CP 83000, Hermosillo, Sonora, México.

e Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial. CP 31109 Chihuahua, Chih., México.

f Departamento de Física, Universidad de Sonora, Apdo. Postal 1626 CP 83000, Hermosillo, Sonora, México.

Keywords: Selenide Cobalt, nanoparticles, characterization, morphology.

Co-Se was obtained using the method of chemical reaction by ion exchange, in which cobalt and

selenium precursors were used. The characterization of optical absorption measured in this work

correspond to the reported from a previously mathematical model, the direct bandgap was 1.7eV and the

indirect bandgap 1.4eV was. The FTIR spectroscopy shows that this research for selenide cobalt,

coincides with previously reported data, which correspond to the one observed in the infrared spectrum.

The corresponding bands appear in 3446 and 1600 cm -1 for the spectrum selenide cobalt and these

correspond to the O-H vibration and bending vibration of H-O-H, respectively. By using Raman

spectroscopy to analyze Co-Se, the frequencies that characterize identified, the corresponding peak was

observed at 192 cm -1 which is the CoSe2. Also in this document XPS study was performed for the Co-

Se is reported, yielding energies of characteristics linked to cobalt and selenium. The characteristic peaks

of cobalt 2p1 and 2p3 were determined at 802 eV and 782 eV , while the peaks of selenium found in 163

eV and 57 eV , and are to 3d5 is 3p3. Finally, the study of the TEM, where small clusters or aggregates of


126

the compound was observed and the corresponding interplanar distances d = 2.28 Å and d= 1.94 Å, which

are corresponding to an orthorhombic structure related to the compound were obtained Co-Se performed.

P-123

SYNTHESIS AND CHARACTERIZATION OF COPPER SELENIDE BY CHEMICAL REACTION USING COPPER NITRATE AND IONS OF SELENIUM IN RONGALITE.

O. Arellano-Tanoria,b,c, E.Chavez-Mendiolaa,b, R. Godoy-Rosasa,d, , T.Mendivil-Reynosoa,e,f, H.A.Pineda-Leona,d, E. Fernadez-Diaza,b, R.Ochoa-Landinf, S.J. Castilloa

a Departamento de investigación en Física, Universidad de Sonora, Apdo. Postal 5-088 CP 83000, Hermosillo, Sonora, México.

b Instituto Tecnologico de Hermosillo, Av. Tecnologico s/n Col. Sahuaro, CP 83170, Hermosillo, Sonora, Mexico.

c Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Sonora Norte, Blvd. Enrique Mazon Lopez No.965, CP 8300, Hermosillo, Sonora, Mexico.

d Departamento de Matemáticas, Universidad de Sonora, Luis Donaldo Colosio y Rosales CP 83000, Hermosillo, Sonora, México.

e Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial. CP 31109 Chihuahua, Chih, México.

f Departamento de Física, Universidad de Sonora, Apdo. Postal 1626 CP 83000, Hermosillo, Sonora, México.

Keywords: Copper Selenide, rongalite, semiconductor, bandgap, and optical absorption.

This paper deals with a method of obtaining copper selenide, this paper reports some

investigations in which it was synthesized copper selenide and form part of this research, because in them,

the results obtained in this paper are validated. Proposed new synthesis method, with which satisfactory

results are similar to those reported in other studies obtained. The method used for the synthesis of copper

selenide by chemical reaction is mainly based on precursors containing selenium and copper. For the case

of copper was used copper nitrate; for selenium source, selenium powder activated with rogalita and

ammonium hydroxide was used. Characterization of optical absorption lead to a direct bandgap of 2.79eV

and an indirect bandgap 1.36eV. Subsequently copper selenide was characterized by FTIR absorption

peaks were observed at approximately 3446 and 1600 cm-1 in to the spectrum of copper selenide, which

correspond to the O-H vibration and H-O-H bending vibration, respectively, this is due to the absorption

H2O in these sample. The peak at 514 cm-1 is related to copper nanoparticles.The following

characterization was done by RAMAN spectroscopy, yielding approximately 258 cm-1, which is

attributed to the binary compounds of copper selenide. XPS binding energies corresponding to Se 3d and

Cu 2p3, are 53 and 953 eV respectively. Using transmission electron microscopy, it was confirmed that it


127

was an orthorhombic crystal structure and the Miller indices were observed [ 0 2 2 ] [ 0 2 3 ] [ 1 1 7 ] [ 1 3

3 ] each index correspond to the interplanar distances 3.208 A, 3.026A, 3.029A y 1.906A.

P-124

THERMOLUMINESCENCE IN SRO THIN FILMS

C.F. Ruiz-Valdez1,a, D. Berman-Mendoza1,b T. Piters1,c, M. Aceves-Mijares2,d

1 Universidad de Sonora (Mexico)

2 Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico)


Keywords: Thermolumiscence, silicon-rich oxide, luminescence, nanoparticles

Different irradiation sources were used to obtain thermoluminescence glow-curves of 550 nm

silicon-rich oxide thin films that were deposited on 3-5 Ω-cm n-type silicon substrates by LPCVD.

Samples with 12, 7 and 5% silicon excess were obtained by varying the flux rate of the precursor gases

N2O and SiH4. Posterior annealing of the films was made to give place to formation of nanoparticles that

are responsible for the different luminescence mechanisms in the material. These percentages and

obtained TL glow-curves can be used to compare previously obtained morphological, optical and

electrical characteristics of the material.

P-125

NANODIAMOND CHARACTERIZATION BY THERMOLUMINESCENCE AND POSSIBLE APPLICATION AS Γ AND X –RAY DOSIMETER

M. Galindo-Bojórquez1a, R. C. Carrillo-Torres1, T. C. Medrano-Pesqueira1, R. Meléndrez2, M. Pedroza-Montero2, P.W. May3, H. A. Durán-Muñoz1, V. Chernov2, and M. Barboza-Flores2b

1Posgrado en Nanotecnología, Departamento de Física, Universidad de Sonora, Hermosillo, Sonora, México

2Departamento de Investigación en Física, Universidad de Sonora, Hermosillo, Sonora, 83000, México

3School of Chemistry, University of Bristol, Bristol BS8 1TS, UK


Keywords: List the keywords that best describe the contents of your paper.

Due that Nanodiamonds (NDs) are biologically compatible they have an extensive variety of

exceptional properties applicable to biology and medicine. Another possible field is radiation dose

assessment by thermoluminescence (TL) for clinical applications. Nevertheless, few works in this matter


128

exist in the literature and some of them are questionable due to the low TL response, high TL substrate

response and small signal to noise ratios. In addition, the TL glow curve of NDs may be affected by the

presence of superficial defects, impurities, the substrate used for growing the ND and even matters related

to the experimental stage, making experiments difficult to perform. In the present work we have

succeeded in obtaining the TL glow curve of MWCVD ND and determined its kinetic behavior associated

to the trapping and radiative recombination mechanisms. The growth conditions were H2(92.9%),

N2(0.6%) and CH4(6.5%) at 1000 K chosen to give a nanocrystalline cauliflower film using manual

abrasion with microdiamond as the nucleation method, that gave grain size around 100 nm. The TL glow

curve found was a broad band from 320-625 K peaked around 480 K irrespective of irradiation source

and with 6.0% reproducibility. The sample was further characterized with Raman, SEM and AFM. To the

best of our knowledge the present results are the first ones on the TL behavior of CVD nanodiamond and

compares well to the only available results on TL of detonation nanodiamond [1]. The dose response of

the NDs exhibited a linear dose behavior at very high doses up to 50 kGy which is consistent with the TL

recently reported in different nanomaterials revealing a high saturation at very high doses [1, 2]. The

results provide evidence of a promising use of CVD ND as TL dosimeter for high energy radiation fields


129

INDEX

GENERAL PROGRAM I

CONFERENCE CHAIR II

ORGANIZING COMMITTEE II

PRESENTATION III

CONFERENCE TOPICS IV

SPEAKERS V

WEEK SCHEDULE VI

FORMAT RESTRICTIONS OF ABSTRACTS VII

PLENARY SESSIONS 1

PLENARY I 1

PLENARY II 1

PLENARY III 2

PLENARY IV 3

PLENARY V 4

PLENARY VI 4

PLENARY VII 5

PLENARY VIII 5


130

PLENARY IX 6

PLENARY X 7

PLENARY XI 8

PLENARY XII 8

PLENARY XIII 8

PLENARY XIV 9

PLENARY XV 10

ORAL SESSIONS 11

O-001 11

O-002 11

O-003 12

O-004 13

O-005 14

O-006 15

O-007 16

O-008 17

O-009 18

O-010 18

O-011 19

O-012 2

O-013 20


131

O-014 21

O-015 22

O-016 23

O-017 24

O-018 25

O-019 25

O-020 26

O-021 27

O-022 28

O-023 29

O-024 29

O-025 31

O-026 31

O-027 32

1ST POSTER SESSION 33

P-001 33

P-002 33

P-003 34

P-004 35

P-005 36

P-006 37

P-007 37


132

P-008 38

P-009 39

P-010 40

P-011 40

P-012 41

P-013 42

P-014 42

P-015 43

P-016 44

P-017 44

P-018 45

P-019 46

P-020 46

P-021 47

P-022 48

P-023 48

P-024 49

P-025 50

P-026 51

P-027 52

P-028 52

P-029 53


133

P-030 54

P-031 55

P-032 56

P-033 57

P-034 57

P-035 58

P-036 59

P-037 60

P-038 60

P-039 61

P-040 62

P-041 62

P-042 63

P-043 64

P-044 65

P-045 66

P-046 66

P-047 67

P-048 68

P-049 69

P-050 69

P-051 70


134

P-052 71

P-053 72

P-054 73

P-055 74

P-056 75

P-057 75

P-058 76

P-059 77

P-060 78

P-061 79

P-062 79

P-063 80

P-064 81

P-065 82

2ND POSTER SESSION 83

P-066 83

P-067 83

P-068 84

P-069 85

P-070 86

P-071 87

P-072 87


135

P-073 88

P-074 89

P-075 90

P-076 90

P-077 91

P-078 92

P-079 93

P-080 93

P-081 94

P-082 95

P-083 96

P-084 96

P-085 97

P-086 98

P-087 99

P-088 100

P-089 101

P-090 101

P-091 102

P-092 103

P-093 103

P-094 104


136

P-095 105

P-096 106

P-097 106

P-098 107

P-099 108

P-100 109

P-101 109

P-102 110

P-103 111

P-104 112

P-105 113

P-106 114

P-107 114

P-108 115

P-109 116

P-110 116

P-111 117

P-112 117

P-113 118

P-114 119

P-115 120

P-116 121


137

P-117 122

P-118 123

P-119 124

P-120 125

P-121 126

P-122 126

P-123 127

P-124 128

P-125 129


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3rd international symposium on nanoscience and nanomaterials

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