NSEC for the Directed Assembly of Nanostructures – 10 years of Impact

and More (in 15 min!)

Linda S. Schadler

NSF Nanoscale Science and Engineering Center

for Directed Assembly of Nanostructures

Rensselaer Polytechnic Institute University of Illinois at Urbana-Champaign

Los Alamos National Laboratory

NSF – NNI Meeting Dec 5-7 – Arlington, VA

Center Mission and PartnersWe will integrate research, education, and technology

dissemination, and serve as an international resource for fundamental knowledge and applications, in the directed

assembly of nanostructures.

K-12 ProgramsUndergraduate Colleges

MorehouseMount Holyoke

OberlinSmith

SpelmanWilliams

UPR MayagüezVisiting Researchers

Industry Partners

ABB

Albany International

Chisso

Eastman Kodak

IBM

Intel

Philip Morris

Sealed Air

New York State

Rensselaer

Polytechnic Institute

University of Illinois

at Urbana-Champaign

NSEC Thrust 1: polymer nanocomposites and gels

Overarching Achievement: Integrated

experimental and theoretical

understanding of structure,

viscoelasticity, and assembly of

nanoparticle-polymer systems bridging

the fields of colloid and polymer science

1) Established integrated experimental and theoretical understanding of the structure

and properties of nanoparticle gels /nanocomposites created by polymer-mediated

interactions

2) A new class of biphasic inks for direct-write assembly based on tunable mixtures

of attractive and repulsive nanoparticles that has already resulted in an order of

magnitude reduction in the size of the 3D features that can be written.

3) Established the role of competing attractive and repulsive forces on nanoparticle

assembly, properties, and dynamics of a broad class of polymer nanocomposites

based on tailored grafted-chain filler particles of controlled architecture.

Biphasic inks for direct-write assembly

Lewis, Moore, Schweizer

3-D lattice1mm

100 m 30 m 1 mm50 µm

10 m

unprecedented 10-fold

size reductiongel-based ink

biphasic ink

PDMAEMA backbone

PEO teeth

silica (FITC)

silica (RITC)

+

PDMAEMA

+

attractive colloids

repulsive colloids

Application – Filters for

Molten Metals (purification)

License Agreement Signed

0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50

e (k

T)

0

1

2

3

4

5fs= 1

fs= 0.75

fs= 0.5

fs= 0.25

GEL

FLUID

GLASS

Total Volume Fraction

NONequilibrium Phase Diagram

f sticky

0 0..2 0.4 0..6 0..8 1

. . . . .10-4

10-3

102

1-1

10

repulsiv

106

Shear Modulus(kT/D3~100 Pa)

104

102

Sticky gel melts

Trends as seen in Expt

Enthalpy - and entropy-driven assembly

Benicewicz, Kumar,

Moore, Schadler,

Schweizer

0 1 2 3 4 5 6 70.00

0.05

0.10

spherical

aggregates

connected/sheet string

dispersed

Gra

ftin

g d

en

sit

y (

ch

ain

s/n

m2)

Grafted chain length / matrix chain length

0 4 8 12 160

2

4

6

8

10

12

Nu

mb

er

of

gra

fte

d c

ha

ins

dispersedstrings

sheets

spherical aggregates

Grafted chain length

Experiment

Theory

Silica nanoparticles functionalized with polystyrene brushes

Good Dispersion

Poor Matrix / Brush Interaction

Good Matrix / Brush Interaction

Interesting Dispersion

σ, Graft Density =0.01 increasing Brush MW

σ = .05 chains/nm2

σ = .1 chains/nm2

0.5μm

PDMS OneBrush36K

BimodalBrush5K/36K

1wt% 8wt%

Can We Make Something Useful?

RAFT polymerization & click chemistry

1.9

1.8

1.7

1.6

1.5

Wavelength

1.8

Ref

ract

ive

Ind

ex

Epoxy, Transparency = 90%

(100 μm thick flims)Silicones have been unattainable

(These are mm in thickness)

Representative curves

13%

Can We Make Something Useful?

•Increased Strain to Failure•Increased Fatigue Resistance

•Increased Electrical Breakdown Strength (30%)

•Order of Mag Improvement in Endurance Strength

•Higher Thermal Conductivity•Lower Coefficient of Thermal

ExpansionZhao, Schadler, Hillborg, Comp, Sci.

Tech. 2008

polymer-polymer

particle-polymer

particle-particle

Complete Multi-Scale Structural Determination

SANS

contrast labeling

Kim, Schweizer, and Zukoski,Phys. Rev. Lett., 2011

First Experiment of its kind in polymer nanocomposites

Excellent agreement of theory with experiment for ALL length scales, volume fractions

KEY idea: interfacial attractions control all statistical structure in the mixtures

Collective Concentration Fluctuations

Theory : single epc

Thrust 2: Nanostructured Biomolecule Composite Architectures

Rationale: Enable the efficient and selective interaction of biomolecules with

synthetic and natural nanoscale building blocks to generate functional assemblies

that benefit industry, the environment, and human health.

Integrating Knowledge and Activities Across Thrust 2

Overarching Achievement: Bridged the fields of biomolecular science with

materials science and engineering. Achieved a fundamental understanding of

molecular events that govern biological function and selectivity in non-biological

nanoscale environments. Impacted applications in sensor design, antifouling

materials, and hierarchical architectures linking the nano- and macro-scales in

biological systems.

Discovered the influence of nanoscale surface curvature on controlling the

structure and function of bound proteins

Achieved an understanding of the concept of hydrophobicity at the molecular

regime

Established design rules for the hierarchical assembly of amphiphilic materials,

including lipid-based membranes, organogels, and virus-like peptides that

restructure cell membranes

Developed highly active and stable self-cleaning/decontaminating surfaces and

highly selective and sensitive DNAzyme- and aptamer-based sensors

Key Accomplishments of Thrust 2:

Influence of nanostuctures on protein function

Lysozyme

Chymotrypsin

NanoBio Materials

and Devices

Gagner, Nuffer, Dordick, Siegel (2010)

Surface Curvature Impacts Protein Stability and Folding

Y

Formation of Enzyme-Carbon Nanotube Conjugates

Thermodynamic Stability of Enzyme-SWNT Conjugates

General Reactive Engineered Enzyme-based Neutralization

Surfaces (GREENS)

S.aureusCell

CellWallDegrada onon

Contact

Pangule et al., ACS Nano, 2010

Wall Street JournalSept. 14, 2010

Lu, coworkers

Real Time Water Testing

Powered by DNA

As a result of that vision – we have:

• Brought together the fields of colloids and nanocomposites

• Bridged understanding between nano / bio interactions

Our Next Area of Impact:

Taking advantage of the fundamental understanding in the nano/bio/polymer space

And translating it (including key manufacturing developments) into applications!

?

• Antimicrobial food packaging

• Antimicrobial textiles

• Biomolecule self healing agents

• Safe Healthcare Environments

NSEC Thrust 3: serving society through

education and outreachHigh School Program (8

Schools Significantly Impacted

Mount Holyoke

PUI Research Program

(60 undergraduates)

The MoleculariumThe Molecularium® Project ….

Riding Snowflakes – the digital-dome

immersive experience (2005 …)

Molecules to the MAX! – the giant-

screen adventure (2009 …)

NanoSpace – the Web-based STEM

educational park (2010 …..)

NanoSpace… the Web-based STEM educational park 2011 …

www.molecularium.com

Industry partnership projects and fellowships:

Fundamental and applied research projects on: electrical,

mechanical, and optical behavior of polymer nanocomposites;

assembled nanoscale structures and biomaterials

Unrestricted gifts averaging almost $1 million annually 2001-2010

Results shared with partner on a royalty-free, non-exclusive basis

Funds are for company-named fellows and distinguished lectures

NSEC spin-off companies:ANDalyze Inc. from Lu laboratory at UIUC

The Paper Battery Co. from Linhardt laboratory at RPI

Solidus Biosciences Inc. from Dordick laboratory at RPI

Technology Transferserving society through transfer of NSEC research to industry

>1000 publications*; >70 patents; 70 graduate degrees; >2K seminars* with many more than 15,000 citations to date