research article effect of water content in ethylene...

Research ArticleEffect of Water Content in Ethylene Glycol Solvent onthe Size of ZnO Nanoparticles Prepared Using MicrowaveSolvothermal Synthesis

Jacek Wojnarowicz1 Agnieszka Opalinska1 Tadeusz Chudoba1 Stanislaw Gierlotka1

Roman Mukhovskyi1 Elzbieta Pietrzykowska12 Kamil Sobczak3 and Witold Lojkowski1

1 Institute of High Pressure Physics Polish Academy of Science Sokolowska 2937 01-142 Warsaw Poland2Faculty of Materials Science and Engineering Warsaw University of Technology Woloska 141 02-507 Warsaw Poland3Institute of Physics Polish Academy of Science Aleja Lotnikow 3246 02-668 Warsaw Poland

Correspondence should be addressed to Jacek Wojnarowicz jacekwojnarowicztlenpl

Received 11 March 2016 Revised 30 May 2016 Accepted 8 June 2016

Academic Editor Muhammet S Toprak

Copyright copy 2016 Jacek Wojnarowicz et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Zinc oxide nanoparticles (ZnO NPs) were obtained by the microwave solvothermal synthesis (MSS) method The precursor of theMSS reaction was a solution of hydrated zinc acetate in ethylene glycol with water addition It was proved that by controllingthe water concentration in the precursor it was possible to control the size of ZnO NPs in a programmed manner The lessthe water content in the precursor the smaller the size of ZnO NPs obtained The obtained NPs with the average particle sizeranging from 25 nm to 50 nm were characterised by homogeneous morphology and a narrow distribution of particle sizes Thefollowing parameters of the obtained ZnONPs were determined pycnometric density specific surface area phase purity chemicalcomposition lattice parameters average particle size and particle size distribution The average size of ZnO NPs was determinedusing Scherrerrsquos formula Nanopowder XRD Processor Demo web application by converting the results of the specific surface areaand TEM tests using the dark field technique ZnOmorphology and structure were determined using scanning electronmicroscopy(SEM) and transmission electron microscopy (TEM) The test performed by the X-ray powder diffraction (XRD) confirmed thatcrystalline ZnO pure in terms of phase had been obtained

1 Introduction

The past decades saw a dynamic development of nanotech-nology [1] The essence of nanotechnology is to make use ofthe correlation between matter properties and matter sizeparticularly when at least one dimension is below 100 nm [2]This opens a large room for scientific discoveries and newapplications Currently nanotechnology not only is developedin scientific laboratories but also accompanies us in everydaylife [3]

The nanotechnology market is growing rapidly [4] Amajor part of that market is the market of nanoparticlesthat is particles of matter sized below 100 nm Nano-ZnOhas a large market share among nanoparticles [5] Owingto its unique physical and chemical properties ZnO is

a multifunctional material [6 7] It is a IIndashVI semiconduc-tor Thanks to the wide band gap of 337 eV high excitonbinding energy (60meV) and thermal stability it is anattractive material for electronics optoelectronics and lasertechnologies for example lasers operating in the ultravio-let range UV radiation detectors or UV emitting diodes[8ndash12] ZnO is a perfect screening material against UVradiation and has a wide characteristic of UV absorptionand is a photostable UVAUVB sunblock agent [13] It isa piezoelectric material [14 15] Zinc oxide is a promisingmaterial for manufacturing solar cells [16] and sensors ofsuch gases as NH

3 NO2 H2S CO

2 CO C

2H5OH and

liquefied petroleum gas (LPG) [17ndash24] The biocompatibilityantibacterial action and biodegradability of ZnO make itan object of great interest of biomedicine [25ndash27] ZnO

Hindawi Publishing CorporationJournal of NanomaterialsVolume 2016 Article ID 2789871 15 pageshttpdxdoiorg10115520162789871

2 Journal of Nanomaterials

layers are also applied as transparent conductive materialsnanostructured electrodes for batteries and components ofdevices with acoustic surface wave [28ndash31] After doping itdisplays new for example paramagnetic ferromagnetic andmagnetooptical properties [10 16 32ndash34] It is widely used asa component of various products such as rubber pigmentscements plastics sealants and paints It is also a componentof pharmaceutical products and cosmetics for example babypowders toothpastes and tooth dressings sunscreens andskin protection balms It is used as a catalyst in organicreactions for example for synthesis of methanol from CO

2

and H2[35]

The properties of ZnO nanostructures are stronglydependent on their size and shape Youngrsquos modulus of ZnOnanowires changes considerably when the shape of theircross section changes [36] The size of ZnO particles exertsa considerable impact above all on the equilibrium constantand the thermodynamic properties of the reaction [37]photoluminescence [38] band gap [39] UV absorption [40]and toxicity [41 42] Particularly piezoelectric parametersmay be greater by several orders of magnitude in comparisonwith ZnO bulk material [36] As a result such methods ofnano-ZnO synthesis are needed that enable a precise controlof the average particle size and obtaining a narrow sizedistribution In order to obtain the required performancecharacteristics it is also necessary that the material is fullycrystalline and characterised by high purity

The relevant literature includes numerous chemicalphysical and biological methods of producing ZnO nanos-tructures of different shapes for example spherical [4344] straw bundle wide chrysanthemum nanorod-basedmicrospheres [45] nanowires [46] nanobelts [47] columns[48] tetrapods [49] helices [50] polyhedral cages and shells[51] tubes rods and needles [43 44 52] flowers [44 53]and irregular crystals and spherical to hexagonal prisms [54]The most often employed laboratory methods of obtainingZnO NPs are calcination precipitation sol-gel electrolyticobtaining and hydrothermal and solvothermal synthesis[55] Microwave hydrothermal and solvothermal synthesiscount as ones of the most popular methods of obtainingnanomaterials [56 57] They are systematically developed byconstructing new types of reactors for example stop-flowand continuous-flow ones [58ndash63]

Syntheses ofmetal oxide nanoparticles in organic solventshave been very popular recently [64ndash66] The main reasonsfor choosing organic solvents in the synthesis of nano-ZnO are nucleation and growth of nanoparticles in highboiling polyols such as ethylene glycol (EG) diethyleneglycol (DEG) tetraethylene glycol (TEG) or glycerol Inthis case the polyol acts as the solvent and the stabilisingagent which restricts particle growth and suppresses particleagglomeration and aggregation Organic solvents also enableobtaining uniformly doped ZnONPs for example with Co2+or Mn2+ions without precipitation of foreign phases [32 33]In addition the synthesis is easy to perform and does notrequiremultistage steps or advanced experimental conditionsor professional reactors

The relevant literature offers several methods of control-ling the size of ZnO NPs obtained in solvothermal synthesis

that is in organic solvents Chieng and Loo [67] described asingle-stage synthesis with control of ZnO NPs size whereas the reaction precursors they used solutions obtained bydissolving Zn(CH

3COO)

2sdot2H2O in EG DEG and TEGThe

average size of the obtained ZnO NPs in EG was 20 nm inDEG 39 nm and in TEG 69 nmThe size control of ZnONPswas explained by the authors with the impact of the chainlength of the polyols used The average particle size of ZnOwas increased in line with the increased glycol chain lengthLian et al in their paper [68] described a synthesis of ZnONPs with controllable size via a solvothermal method usinga mixed solvent system The average size of the NPs can betailored within the range from 15 nm to 25 nm by adjustingthe volume ratio of ethanolEGWang et al [69] were ones ofthe first scholars to describe the solvothermal synthesis withcontrolled size of ZnO microstructures by adding water tothe organic solvent A solution of zinc acetate dissolved inmethanol was used as the reaction precursor However ZnOmicrostructures obtained in that manner contained foreignphases and were heterogeneous Wang suggested that themechanism of ZnO size control by changing theH

2O content

in the precursor was the probable impact of water on thesimultaneous course of hydrolysis of Zn(CH

3COO)

2as well

as of the generated intermediates Bitenc and Crnjak Orel[70] described a one-step solution phase preparationmethodused for the preparation of nano- and submicrometre-sizedZnO As the reaction precursor they used a mixture ofZn(NO

3)2sdot6H2Oand urea in solventsThe paper shows a syn-

thesis of ZnO structures which can be controlled by changingthe types of solvents water and waterpolyol where a partof the water is substituted with EG DEG and TEG It wasindicated in the example of EG that the size of the structuresdecreased in line with increasing volumeconcentration ofthe added EG The publication by Li et al [71] is anotherone which confirms the possibility of controlling the size ofZnO NPs by changing water concentration in the precursorsuspension obtained by mixing Zn(CH

3COO)

2+ NaOH

+ tetradecane in EG The authors obtain ZnO NPs by amultistage method within the size range between 18 nmand 436 nm However based on the provided results thephase purity of all obtained samples of ZnO NPs cannot beconfirmed

It was determined that water exerts a significant impacton the course of solvothermal synthesis and even smallamounts of H

2O in organic solvents promote crystal growth

[72] However papers of most scholars do not take intoaccount the presence and changes in the concentration ofwater in the precursor despite the fact that water is suppliedto the precursor in two ways with a hydrated salt forexample Zn(CH

3COO)

2sdot2H2O and togetherwith an organic

solvent wherein it occurs in trace quantities [67 68] Themechanism of growth and size control of ZnO crystals inorganic solvents has not been unambiguously explained sofar [73ndash77] It should be remembered that each mechanismof ZnO synthesis should be treated individually This resultsfrom the diversity of precursors used and at the same timefrom the multitude of obtainable intermediates belonging tothe group of metalorganic compounds [78]

Journal of Nanomaterials 3

In the present paper we report the control of the size ofnano-ZnO particles in a simple chemical reaction where theonly ingredients of the reaction substrates are zinc acetateethylene glycol and water Although water is always presentin ethylene glycol and zinc acetate its precise amount canbe controlled in experimental conditions The particle sizeis a function of the amount of water in the precursor Forthe synthesis we used the microwave solvothermal synthesis(MSS) method [58]

2 Experimental Methods

21 Chemicals Hydrated zinc acetate (Zn(CH3COO)

2sdot

2H2O) analytically pure SKU 112654906-1KG and ethylene

glycol (ethane-12-diol C2H4(OH)2) pure SKU 114466303-

5L purchased from Chempur were used The reagents wereused without additional purification Deionised water withspecific conductance below 01 120583Scm was obtained using adeioniser (HLP 20UV Hydrolab Poland)

22 Preparation of ZnO Nanopowders Zinc oxide wasobtained by the microwave solvothermal synthesis (MSS)technique [32] The reaction precursor solution of zinc

acetate in ethylene glycol (Table 1) was prepared using a hot-plate magnetic stirrer (SLR SI Analytics Germany) at theconstant temperature of 70∘C and stirring speed of 450 rpmAfter complete dissolution of zinc acetate the solution waspoured to five 100mL PP containers and closed tightly Aftercooling down to the ambient temperature an analysis ofwater content in the precursorwas carried out (101ofH

2O)

An appropriate calculated amount of H2O was added to the

precursor to obtain the intended water content (Table 1) andsubsequently the solution was stirred again and an analysis ofwater content in the prepared precursorwas carried outThen70mL of the solutionwas poured to a 110mLTeflon reactioncontainer and closed tightly Thus prepared precursor in thereaction container was put into the microwave reactor Theabove operations were repeated for each sample in order toachieve the following water concentrations in the precursor15 2 3 and 4

The reaction initiated with microwave radiation wascarried out in Magnum 02-02 reactor (600W 245GHzERTEC Poland) The diagram of the microwave reactorstructure is presented in Figure 1 The synthesis of zinc oxidein ethylene glycol is described by the following generalreaction equation

(CH3CO2)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP

997888997888997888997888997888997888997888997888997888997888997888997888997888997888997888rarr ZnOdarr+ other products (liquid or gas) (1)

The reaction duration was 25 minutes temperature 220∘Cand power 100 and after that the reaction containerwas cooled down for 20 minutes After the synthesis theobtained powder was sedimented rinsed three times withdeionised water centrifuged (MPW-350 MPW Med Instru-ments Poland) and dried in a freeze dryer (Lyovac GT-2SRK Systemtechnik GmbH Germany)

23 X-Ray Powder Diffraction Diffraction patterns of the X-ray powder diffraction (XRD) were gathered at the roomtemperature within the range of 2-theta angle from 10∘ to 100∘with the step of 002∘ using the X-ray powder diffractometer(119862119906119870

1205721) (XrsquoPert PRO Panalytical Netherlands) [81] The

parameters of the crystalline lattice were determined by theRietveld method implemented in Fityk software version098 Based on the diffraction patterns the size of crystalliteswas determined in the direction of the crystallographic axes119886 and 119888 using Scherrerrsquos formula in the following form

119863

ℎ119896119897=

119870 sdot 120582

120573 sdot cos 120579ℎ119896119897

(2)

In the above equation Scherrerrsquos formula119863ℎ119896119897

is the volumeweighted crystallite size (nm)119870 is the shape factor (119896 = 09)120582 is the wavelength of the X-rays (120582 = 0154056 nm for119862119906119870

1205721

radiation) 120579ℎ119896119897

is the Bragg diffraction angle (∘) 120573 is thebroadening of the ℎ119896119897 diffraction peak measured at half of itsmaximum intensity (in radians) [82]

24 Crystallite Size Distribution The analysis of XRD peakprofile was performed using the analytical formula for poly-dispersive powders [83] While Scherrer method provides asingle size parameter this technique provides four parame-ters average crystallite size error of the average crystallitesize dispersion of size and error of dispersion of sizes Hencea full crystallite size distribution curve and an estimation ofldquothicknessrdquo of this curve (error bars) are obtained

The online tool Nanopowder XRD Processor Demo(httpscience24comxrd) is a webpage where diffractionfiles can be directly dropped [84] Files are processed ona server to extract the crystallite size distribution for XRDpeaks [80] Unlike the standard fitting the tool does notact in the reciprocal space at all but solves sets of equationsin a few auxiliary spaces simultaneously This allows ananalysis of XRDdatawith heavily convoluted reciprocal spacepeaks

25 Measurement of Density and Specific Surface Area Den-sity measurements were carried out using the helium pyc-nometer [85] (AccuPyc II 1340 FoamPyc V106 Micromerit-ics USA) the measurements were carried out in accordancewith ISO 121542014 at temperature of 25 plusmn 2∘C Density of amaterial obtained using helium pycnometry is called skeletondensity pycnometric density true density and heliumdensityin the relevant literature The specific surface area of NPswas determined using the surface analyser (Gemini 2360 V201 Micromeritics USA) by gas adsorption method basedon the linear form of the BET (Brunauer-Emmett-Teller)


(a) (b)

Pressure safetyvalve and control

Pressure vessel(jacket)

Reactor

Antenna

WaveguideMagnetron

ThermocoupleController

(regulation set)

Remotecontroller

(c)

Figure 1 Magnum 02-02 ERTEC microwave reactor (a) reactor photograph (b) Teflon reaction container and (c) reactor diagram [79]

Table 1 Water content in ethylene glycol and in the precursorwith constant concentration of Zn(CH

3COO)

2sdot2H2O which was

03254moldm3 for all samples

Sample 119862119901H2O[wt]

Ethylene glycol solvent 027 plusmn 001ZnO (1) 101 plusmn 004ZnO (15) 141 plusmn 007ZnO (2) 189 plusmn 011ZnO (3) 293 plusmn 013ZnO (4) 389 plusmn 011

isotherm equation [86] in accordance with ISO 92772010Prior to performing measurements of density and specificsurface area the samples were subject to 2 h desorption ina desorption station (FlowPrep 060 Micromeritics USA) attemperature of 150∘C with the flow of helium of 999999purity Based on the determined specific surface area andpycnometric density the average size of particles definingtheir diameter was determined with the assumption thatall particles are spherical and identical [87] The followingequation was used for calculating the average particle size

119863 =

119873 sdot 1000

SSA sdot 120588 (3)

The above equation is for calculating the average particle sizewhere 119863 is average size (diameter) of particles [nm] 119873 isshape coefficient being 6 for the sphere [88 89] SSA is specificsurface area [m2g] and 120588 is density [gcm3]

26 Morphologic Characteristics and Energy Dispersive Spec-trometry (EDS) The morphology of NPs was determined

using the scanning electron microscopy (SEM) (ZEISSULTRAPLUSGermany) Powder sampleswere coatedwith athin carbon layer using the sputter coater (SCD005CEA 035BAL-TEC Switzerland) An internal laboratory measure-ment procedure was applied (P510 edition 6 of 26082015)

The morphology of the nanopowder samples was exam-ined usingTEM-JEOL JEM2000EX andTitanCubed 80ndash300The TEM tests using the dark field (DF) and selected areaelectron diffraction (SAED) were conducted at 200 kV High-resolution transmission electron microscopy (HRTEM) testswere conducted at 300 kV The specimens for the TEMobservations were prepared by dropping the ethanol particledispersion created by an ultrasonic technique on a carbonfilm supported on a 300-mesh copper grid TEM tests wereused to determine the nanoparticle size distribution Thegrain size histograms were obtained by considering a regionof a sample having about 250 nanocrystals and approximatingthe shape of each nanocrystal by a sphere The obtainedhistograms were fitted to lognormal distributions [90]

Samples of ZnO NPs for the EDS measurement werepressed to the form of pastilles with diameter of 5mm Thequantitative X-ray microanalysis was carried out using theEDS analyser (Quantax 400 Bruker USA)

27 Water Content Analysis The quantitative analysis ofwater in the precursor was carried out in accordance with theassumptions of the Karl Fischer method using the coulomet-ric titration technique with the titrator (Cou-Lo AquaMAXKF GR Scientific Great Britain) An internal laboratorymeasurement procedure was applied Liquid samples wereintroduced to the titration vessel using a glass syringe (1mL)with a Luer type needle An analytical scale was used forweight measurement (WAA 100C1 RADWAG Poland)


100nm

(a)

100nm

(b)

100nm

(c)

100nm

(d)

100nm

(e)

Figure 2 The SEM images of the ZnO nanoparticles with various water content in the precursor (a) 1 (b) 15 (c) 2 (d) 3 (e) 4

200nm

(a)

200nm

(b)

200nm

(c)

200nm

(d)

200nm

(e)


3 Results and Discussion

31 Morphology Figures 2 and 3 present representative SEMimages of ZnO NPs of all obtained powders Figure 2 showsthe homogeneous morphology and spherical shape of ZnONPs Figures 4 and 5 are TEM images of the obtainedZnO NPs They show agglomeratesaggregates composedof homogeneous ZnO particles It can be noticed in TEMimages that a change in water content affects the size andshape of NPs Figures 4 and 5 prove that the samples are

composed of NPs with the spherical and hexagonal shape Inline with water content growth in the precursor the shapeof NPs gradually changes from spherical through ellipticalto hexagonal (Figures 4 and 5) For 1 water content inthe precursor the dominant population is NPs with thespherical shape (Figures 4 5 and 6) NPs with the hexagonalshape prevail in the sample obtained from the precursor with4 water content Particle size between 15 and 40 nm wasobserved in SEM and TEM images for 1 water contentwhile for the samples of ZnO NPs with 4 water addition


50nm

(a)

50nm

(b)

50nm

(c)

100 nm

(d)

100 nm

(e)

Figure 4 The TEM images of the ZnO nanoparticles with various water content in the precursor (a) 1 (b) 15 (c) 2 (d) 3 (e) 4

the particle size was between 20 and 100 nm Figure 6 showsschematically the effect observed by us of water content onthe morphology of the nanoparticles Based on the results weobtained we can confirm that water exerts a very significantimpact during the growth of ZnO crystals on their shapeA similar impact of water on the shape and size of theobtained ZnO NPs is described by other papers [43 6769 71] The primary problems in obtaining ZnO NPs arethe lack of simultaneous control over shape size and sizedistribution of particles It is presumed that there are severalcompetitive mechanisms of ZnO reactions which occurin parallel and are very sensitive to a change in synthesisconditions and precursor preparation which would explainobtaining diverse ZnO nanostructures in terms of shape andsize [55]

32 Phase Composition All diffraction peaks (Figure 7) canbe well indexed to the hexagonal phase ZnO reported inJCPDS card number 36-1451 (Table 2) confirming that onlynanocrystalline ZnO was detected within the resolution ofthe XRD method No characteristic diffraction peaks fromunreacted substrates Zn(OH)

2 or other phases or impurities

were observed which are frequently seen in the hydrothermalsynthesis of ZnO Figure 7 displays a noticeable differencebetween the widths of diffraction peaks of ZnONPs samplesThe higher the water content in the precursor the narrower

Table 2 Standard JCPDS card of bulk ZnO with hexagonalstructure (JCPDS number 36-1451)

2120579 (∘) Intensity ℎ 119896 119897

31728 578 1 0 034400 442 0 0 236212 999 1 0 147494 229 1 0 256519 324 1 1 062803 276 1 0 366283 44 2 0 067866 243 1 1 268992 114 2 0 172516 19 0 0 476860 38 2 0 281315 19 1 0 489500 74 2 0 3

the diffraction peaks observed and at the same time thegreater the size of obtained ZnO crystallites

No influence of the particle size on 119886 and 119888 latticeparameters was observed (Table 3 Figure 8) The 119886 and 119888crystalline lattice parameters for ZnO assume the followingvalues for a from 32496 A to 32502 A and for 119888 from 52057 A


Table 3 Lattice parameter of ZnO NPs

Sample Lattice parameter Ratio of latticeparameter 119888119886 plusmn 120590

In hcp structure ZnO ratio oflattice parameter 119888119886

119886 plusmn 120590 [A] 119888 plusmn 120590 [A]ZnO (1) 32502 plusmn 00003 52061 plusmn 00004 16018 plusmn 00003

16330

ZnO (15) 32502 plusmn 00003 52061 plusmn 00004 16018 plusmn 00003ZnO (2) 32499 plusmn 00003 52057 plusmn 00004 16018 plusmn 00003ZnO (3) 32497 plusmn 00003 52059 plusmn 00004 16020 plusmn 00003ZnO (4) 32496 plusmn 00003 52059 plusmn 00004 16020 plusmn 00003ZnO (JCPDS number 36-1451) 32498 52066 16021

10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)

Figure 5 The TEM images of the ZnO nanoparticles (a) 1 H2O (b) 15 H

2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)

Figure 6 Overview shapes of ZnO NPs for samples (a) 1 H2O (b) 2 H

2O (c) 4 H

2O


Table 4 Results of chemical analyses of ZnO nanopowders

Sample EDS Stoichiometry of obtained ZnOZn [value plusmn 120590 at] O [value plusmn 120590 at] ZnO ratio [value plusmn 120590]

ZnO (1) 5126 plusmn 027 4874 plusmn 027 105 plusmn 002 Zn1O0951





Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)

Figure 7 XRD pattern of ZnO nanoparticles and its comparisonwith the standard pattern of ZnO in wurtzite phase (JCPDS number36-1451)

ac

29 34 39 44 4924Average particle size from SSA (nm)

52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)

Figure 8 Lattice parameter of ZnO NPs

to 52061 A where their 119888119886 ratio is circa 1602 and is closeto a close packed hexagonal structure 119888119886 = 1633 [7] Theobtained results for 119888119886 reveal that a change in ZnO NPs sizedoes not lead to a change in the proportions of dimensionsof the unit cell (Table 3 Figure 8) However a change inthe crystallite dimension 119889

119888119889

119886ratio was observed (Table 5)

which indicates a reorientation of proportions of crystallitesizes and the shape from spherical to ellipticalhexagonalwhich was confirmed also by TEMmicroscopic tests (Figures4 and 5)

33 Density and Specific Surface Area Theoretical density ofZnO is 561 gcm3 Pycnometric density of the obtained ZnONPs ranged from529 gcm3 to 543 gcm3 for the size range ofNPs from 25 nm to 50 nm (Table 5)The observed correlation

532 536 540 544528Skeleton density (gcm3)

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)

Figure 9 Correlations between specific surface area and density ofZnO NPs

between the particle size and density is well known andexplained by the influence of their size changes on

(i) quantity of amorphous phase hydroxides and crys-talline H

2O [91]

(ii) quantity of occurring surface defects [92](iii) quantity of defects of the crystalline lattice and non-

stoichiometry of ZnO [93](iv) presence of impuritiesdoping [94]

Figure 9 shows a correlation between density and specificsurface area of NPs As already mentioned it is understand-able that in line with an increase in NPs size density increasesand specific surface area decreases For the smallest obtainedNPs with particle size of 25 nm the specific surface area was46m2g with their density being equal to 529 gcm3 ForNPssized 50 nm specific surface area amounted to 22m2g withtheir density being equal to 543 gcm3 The same correlationof the influence of particle size change on their density andspecific surface area was observed in the case of ZrO

2NPs and

hydroxyapatite NPs [90 91]

34 Chemical Composition The analysis of the chemicalcomposition was carried out by EDS method The chem-ical composition of ZnO showed some nonstoichiometry(Table 4) Excess of zinc atoms being circa 5-6 at in relationto oxygen atoms is noticeable The XRD test did not revealpresence of foreign phases Quantity of 5-6 at of the foreignphase is at the limit of the diffractometric method detectionHowever the tests of the chemical composition did notindicate presence of other atoms than zinc oxygen andcarbon Carbon was introduced to the samples through thecoating process prior to the EDS measurement and could


Table 5 Characteristic of the ZnO NPs samples

SampleSpecific surfacearea by gasadsorption119886

119904plusmn 120590 (m2g)

Skeleton densityby gas

pycnometry120588

119904plusmn 120590 (gcm3)

Average particlesize from SSA

BET 119889 plusmn 120590 (nm)

Average crystallitesize from

Nanopowder XRDProcessor Demo119889 plusmn 120590 (nm)

Averagecrystallite sizeScherrerrsquos

formula based onXRD 119889

119886 119889119888(nm)

Ratio of averagecrystallite sizeScherrerrsquos

formula 119889119888119889

119886

Average particlesize from TEM119889 plusmn 120590 (nm)

ZnO (1) 46 plusmn 1 529 plusmn 008 25 plusmn 1 22 plusmn 7 18 23 1278 198 plusmn 03ZnO (15) 39 plusmn 1 535 plusmn 008 29 plusmn 1 26 plusmn 8 23 29 1261 246 plusmn 03ZnO (2) 36 plusmn 1 537 plusmn 005 31 plusmn 1 29 plusmn 10 24 33 1375 248 plusmn 03ZnO (3) 29 plusmn 1 540 plusmn 003 38 plusmn 2 35 plusmn 12 30 39 1300 281 plusmn 03ZnO (4) 22 plusmn 1 543 plusmn 007 50 plusmn 3 41 plusmn 14 33 48 1455 657 plusmn 03

contribute to a possible understatement of the results ofthe quantitative oxygen analysis The at ZnO ratio forall samples amounts to asymp105ndash106 Nonstoichiometry ofZnO is well known and leads to the presence of pointdefects (interstitials and vacancies) and extended defects(threadingplanar dislocations) [95] Nonstoichiometry maybe one of the reasons for the lower density of the obtainedZnO NPs than the theoretical density (Table 5) No influenceof the changes in particle sizes on ZnO stoichiometry wasobserved (Table 5)

35The Average Size and Size Distribution of NPs The resultsare summarized in Table 5 The average size of ZnO NPscalculated based on the results of specific surface area anddensity ranged from 25 nm to 50 nm (Table 5) The averagesize calculated by this method is most representative in termsof quantity of the tested sample The particle size determinedbased onXRD tests using the Scherrermethod ranges from23to 48 nm (Table 5) On the other hand theNanopowder XRDProcessor Demo [84] web application based on diffractiontheory [83] permits obtaining the crystallite size distributionand average size The average crystallite size between 22 plusmn 7and 41 plusmn 14 nm with a narrow size distribution was obtained(Figure 10) Figure 11 includes the distribution of ZnO samplesizes obtained based on TEM tests using the dark fieldtechnique An increasing trend of the average particle sizefrom 198 plusmn 03 to 657 plusmn 03 with a narrow size distributionis noticeable

When comparing different methods of converting XRDresults Scherrerrsquos formula and Nanopowder XRD ProcessorDemo similar results were obtained falling within thestandard deviation of the methods The results of the XRDmethod calculated using Scherrerrsquos formula coincide with theaccuracy of 2 nm with the results of the method based onthe results of surface area and density The average size ofparticles of ZnO samples obtained by TEM method displaysa certain discrepancy of results when compared with othermethods These discrepancies may be caused by the quantityof the tested sample In theTEMmethodmerely 250 particleswere analysed while in the case of other methods the particlequantities were in the order of billions Another cause maybe an assumption for example that a particle is sphericalwhich can be an error since Figure 7 reveals that the shape of apart of the particle population is often oval or hexagonalTheadopted assumptions of the methods generate a certain error

Inte

nsity

(cou

nts)

ZnO (4) 41nmZnO (3) 35nm

ZnO (2) 29nmZnO (15) 26nmZnO (1) 22nm

25 50 75 1000Size of crystallite (nm)

Figure 10 Crystallite size distribution obtained using NanopowderXRD Processor Demo pre120572ver008 copy Pielaszek Research [80]

in the obtained results However currently it is technicallyimpossible to individually take into account the actual shapeof each particle while performing the calculations Anothercause of the discrepancies between the results of size distri-bution can be the fact that in the TEM methods particlesare counted by their quantity while in XRD methods theyare counted by their volume Certain differences betweenthe results of different measurement methods are alwaysnoticeableThemore the indirectmethod (algorithm) is usedthe more the results will differ [96] However in generalall the used size characterisation methods lead to consistentresults Therefore it can be implied that

(i) ZnO NPs are monocrystalline

(ii) the size of ZnO NPs is equal to the crystallite size

(iii) nanoparticles do not form aggregates


15 20 25 30 35 40 45 5010Size of the nanoparticles (nm)

0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990

y0 = 15 plusmn 09xc = 198 plusmn 02

(a)

20 30 40 50 60 70 8010Size of the nanoparticles (nm)

0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s

40 60 80 10020Size of the nanoparticles (nm)

Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)

Figure 11 The histogram of the particle size distribution of ZnO (a) 1 H2O (b) 15 H

2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O


Normally one ZnO particle is composed of several crys-tallites which means that particle sizes are much greaterthan crystallite sizes However in our case the synthesis inethylene glycol results in producing ZnO NPs composed ofmonocrystallites

The narrow size distribution of the obtained ZnO NPsand their homogeneous morphology result from the use ofa microwave source of heating in the solvothermal synthesisMicrowave solvothermal syntheses are characterised by con-siderably shorter reaction times in comparison with standardheatingmethodsThe sample is heated quickly and uniformlydue to the direct particle heating through the energy ofmicrowaves This method is designated as endogenous orvolumetric heating [59] which means that heat is generatedwithin the whole volume of the sample and not transportedthrough the reaction vessel walls from an external heatsource When comparing the method of microwave heatedsynthesis with standard heating differences in parameters ofthe obtained products result from the pure thermalkineticeffect and not from ldquospecificrdquo or ldquononthermalrdquo microwaveeffects in the preparation of nanomaterials [97] In his paperSchanche [98] showed the temperature profile after 60 sec asaffected by microwave irradiation compared to a treatmentin an oil-bath This is an excellent example indicating a smalltemperature gradient of samples heated by microwaves incomparison with the standard method Reaction vessels ofmicrowave reactors are primarily formed in Teflon whichis characterised by a low coefficient of thermal conductivity(025W(msdotK)) and acts as a thermal insulator thanks towhich a very small temperature gradient is achieved [58 59]In our paper through the use of a contactless heatingmethodbeing microwave radiation and of a reaction vessel formed ina chemically inertmaterial we obtain ZnONPs characterisedby high chemical purity

36 Programming the Size of ZnO NPs The particle sizedependence on water content is shown in Figure 12 For

simplicity we assumed a linear dependence 119910 = 119886119909+119887 wherethe values 119886 and 119887 are constants and 119910means the average sizeof NPs while 119909 is water concentration in the precursor Thecalibration curve was determined using the linear regressionbased on experimental data The following function formulawas obtained 119910 = 823119909 + 1627 (1198772 = 09721) whichenables programming the average size of ZnO particles fora given batch of the reagents used and constant parametersof synthesis As already mentioned the synthesis of ZnONPs is sensitive to each change of the precursor causedfor example by the composition and purity of reagents Inorder to preserve the accuracy of particle size control whenchanging a batch of reagents the operation of determiningthe calibration curve of ZnO NPs size should be performedagain Because both density and specific surface area dependon water content in the precursor (Figure 13) also calibrationcurves concerning these properties in the water contentfunction can be determined A calibration curve for NPssynthesis can be obtained for ZnO sizes up to 120 nm [99]

37 Synthesis Mechanism The dependence of ZnO NPs sizeon water concentration in glycol can be explained by twophenomena

(1) increased dissociation degree of Zn(CH3COO)

2sdot

2H2O as a result of increased concentration of H

2O

in ethylene glycol

(2) increased size of zinc organic compound clustersfrom which ZnO NPs crystalize

The probable mechanism of the reaction of microwavesolvothermal synthesis of ZnO NPs is presented by thefollowing equations (4) dissociation (5) cluster growth (6)crystallization (7) esterification and (8) abridged synthesisequation

(CH3COO)

2Zn sdot 2H

2O

H2O

997888997888997888rarr (CH3COO)Zn+ sdot 2H

2O + CH

3COOminus (4)

5 (CH3COO)Zn+ sdot 2H

2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)

2sdot 2H2O TP997888997888rarr 5ZnO

darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP

997888997888997888997888997888997888997888997888997888997888997888997888997888997888997888rarr ZnOdarr+ 2H2O + CH

3COOC

2H4OH + CH

3COOH (8)

Two types of water are present in the precursor structuralwater which is bound chemically and is an integral part ofZn(CH

3COO)

2sdot2H2O and water present in ethylene glycol

Water present in ethylene glycol causes only dissociation ofZn(CH

3COO)

2sdot2H2O (4) and formation of clusters of zinc

organic compounds Zn5(OH)8(CH3COO)

2sdot2H2O (5) Acetic

acid is a weak organic acid so it was assumed that in thesolution of glycol with water it would dissociate only to theform (CH

3COO)Zn+sdot2H

2OWater addition to the precursor

results in increasing the quantity of the dissociated form(CH3COO)Zn+sdot2H

2Oand as a consequence in increasing the

available building material necessary for cluster growth (4)


y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)

1 2 3 40Water content in precursor (wt)

R2 = 09721

Figure 12 Calibration curve of average particle size in the functionof water content in the precursor

SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)

2 3 41Water content in precursor (wt)

527529531533535537539541543545

Den

sity

(gc

m3 )

Figure 13 Value of specific surface area and density of ZnO NPs inthe function of water content in the precursor

Under influence of temperature clusters grow and precipitatein the form of sediment Particle size depends strictly on thesize of the formed clusters from which ZnO NPs crystalizeunder influence of temperature Probably only structuralwater coming from Zn(CH

3COO)

2sdot2H2O takes part in the

ZnO (4)ndash(6) synthesis reaction In other words the achievedcontrol of NPs size by controlling water concentration inthe precursor results from a changed growth dynamics ofZn5(OH)8(CH3COO)

2sdot2H2O clusters The primary reaction

products apart from ZnO NPs are also water and acetic acidAnother possible chemical reaction being a consequence ofZnO synthesis is esterification reaction (7) in which aceticacid and ethylene glycol participate The presence of estersin the postreaction suspended matter in the solvothermalreaction of zinc acetate in various alcohols was confirmedby Tonto et al [100] An undesirable side reaction whichmay occur simultaneously with ZnO synthesis is the reactionof degradation or polymerisation of ethylene glycol Furtherresearch is required to confirm the role of H

2O and synthesis

mechanism in this case

4 ConclusionsA method of controlling the average size of homogeneousZnO NPs ranging from 25 to 50 nm with a narrow size

distributionwas developed Zinc acetate dissolved in ethyleneglycol with water addition was used as the precursor ofmicrowave solvothermal synthesis It was found that anincrease in water content in ethylene glycol in the MSS led toan increase in the size of ZnONPsThat result was interpretedas follows water addition increases the dissociation degreeof Zn(CH

3COO)

2sdot2H2O which leads to an increase in the

size of the forming clusters of zinc organic compounds fromwhich ZnO NPs crystalize under influence of temperatureThemorphology and density of the NPs depend on their sizeZnO NPs were characterised by homogeneous morphologyThe shape changed from spherical to hexagonal in linewith the increase in the nanoparticle size The method ofnanoparticle size control discovered by us may be used foroptimising ZnO properties in specific applications

Competing Interests

The authors declare that there are no competing interestsregarding the publication of this paper

Acknowledgments

The work reported here was conducted in the ShymanProject Grant Agreement no 280983 (2012ndash2016) under the7th Framework Programme of the European Commissioncoordinated by E Lester (The University of NottinghamUnited Kingdom httpwwwshymaneu) The research sub-ject was carried out with the use of equipment funded by theproject CePT reference POIG020200-14-02408 financedby the European Regional Development Fund within theOperational Programme ldquoInnovative Economyrdquo for 2007ndash2013 HRTEMmeasurements have been carried out in the IFPAN within the project ldquoAnalytical High Resolution Trans-mission ElectronMicroscope for Nanoscience Nanotechnol-ogy And Spintronicsrdquo number POIG0201-00-14-03208Theauthors would like also to thank J Mizeracki A Presz and SKusnieruk from the Institute of High Pressure Physics of thePolish Academy of Sciences

References

[1] M Loos ldquoChapter 1-nanoscience and nanotechnologyrdquo inCarbon Nanotube Reinforced Composites CNR Polymer Scienceand Technology pp 1ndash36 2015

[2] O L Stroyuk V M Dzhagan V V Shvalagin and S YKuchmiy ldquoSize-dependent optical properties of colloidal ZnOnanoparticles charged by photoexcitationrdquoThe Journal of Phys-ical Chemistry C vol 114 no 1 pp 220ndash225 2010

[3] M E Vance T Kuiken E P Vejerano et al ldquoNanotechnologyin the real world redeveloping the nanomaterial consumerproducts inventoryrdquo Beilstein Journal of Nanotechnology vol 6no 1 pp 1769ndash1780 2015

[4] J J Ramsden ldquoApplied nanotechnologyrdquo in A Volume in MicroandNanoTechnologies pp 49ndash60 ElsevierNewYorkNYUSA2014

[5] Future Markets Nanoparticles and Zinc Oxide The GlobalMarket 2nd edition 2014


[6] D Segets J Gradl R K Taylor V Vassilev and W PeukertldquoAnalysis of optical absorbance spectra for the determinationof ZnO nanoparticle size distribution solubility and surfaceenergyrdquo ACS Nano vol 3 no 7 pp 1703ndash1710 2009

[7] U Ozgur Y I Alivov C Liu et al ldquoA comprehensive review ofZnO materials and devicesrdquo Journal of Applied Physics vol 98no 4 Article ID 041301 pp 1ndash103 2005

[8] A Ashrafi andC Jagadish ldquoReview of zincblende ZnO stabilityof metastable ZnO phasesrdquo Journal of Applied Physics vol 102no 7 Article ID 071101 2007

[9] E BacaksizM ParlakM Tomakin A OzcelikMKarakiz andM Altunbas ldquoThe effects of zinc nitrate zinc acetate and zincchloride precursors on investigation of structural and opticalproperties of ZnO thin filmsrdquo Journal of Alloys and Compoundsvol 466 no 1-2 pp 447ndash450 2008

[10] U Ozgur D Hofstetter and H Morkoc ldquoZnO devices andapplications a review of current status and future prospectsrdquoProceedings of the IEEE vol 98 no 7 pp 1255ndash1268 2010

[11] A B Djurisic A M C Ng and X Y Chen ldquoZnO nanos-tructures for optoelectronics material properties and deviceapplicationsrdquo Progress in Quantum Electronics vol 34 no 4 pp191ndash259 2010

[12] M Willander Q X Zhao Q-H Hu et al ldquoFundamentals andproperties of zinc oxide nanostructures optical and sensingapplicationsrdquo Superlattices and Microstructures vol 43 no 4pp 352ndash361 2008

[13] M AMitchnick D Fairhurst and S R Pinnell ldquoMicrofine zincoxide (Z-Cote) as a photostable UVAUVB sunblock agentrdquoJournal of the American Academy of Dermatology vol 40 no1 pp 85ndash90 1999

[14] L Z Kou W L Guo and C Li ldquoPiezoelectricity of ZnO and itsnanostructuresrdquo in Proceedings of the Symposium on Piezoelec-tricity Acoustic Waves and Device Applications (SPAWDA rsquo08)pp 354ndash359 Nanjing China December 2008

[15] Z L Wang ldquoNovel nanostructures of ZnO for nanoscale pho-tonics optoelectronics piezoelectricity and sensingrdquo AppliedPhysics A vol 88 no 1 pp 7ndash15 2007

[16] L Schmidt-Mende and J L MacManus-Driscoll ldquoZnOmdashnanostructures defects and devicesrdquo Materials Today vol 10no 5 pp 40ndash48 2007

[17] R Kumar O Al-Dossary G Kumar and A Umar ldquoZinc oxidenanostructures for NO

2gasmdashsensor applications a reviewrdquo

Nano-Micro Letters vol 7 no 2 pp 97ndash120 2015[18] P S Shewale Y S Yu JHKimC R Bobade andMDUplane

ldquoH2S gas sensitive Sn-doped ZnO thin films synthesis and

characterizationrdquo Journal of Analytical and Applied Pyrolysisvol 112 pp 348ndash356 2015

[19] S K Gupta A Joshi andM Kaur ldquoDevelopment of gas sensorsusing ZnO nanostructuresrdquo Journal of Chemical Sciences vol122 no 1 pp 57ndash62 2010

[20] V R Shinde T P Gujar C D Lokhande R S Mane and S-H Han ldquoDevelopment of morphological dependent chemicallydeposited nanocrystalline ZnO films for liquefied petroleumgas (LPG) sensorrdquo Sensors and Actuators B Chemical vol 123no 2 pp 882ndash887 2007

[21] C Dighavkar ldquoCharacterization of nanosized zinc oxide basedammonia gas sensorrdquo Archives of Applied Science Research vol5 pp 96ndash101 2013

[22] P Rai W-K Kwak and Y-T Yu ldquoSolvothermal synthesis ofZnO nanostructures and their morphology-dependent gas-sensing propertiesrdquo ACS Applied Materials and Interfaces vol5 no 8 pp 3026ndash3032 2013

[23] E Dilonardo M Penza M Alvisi et al ldquoEvaluation of gas-sensing properties of ZnO nanostructures electrochemicallydoped with Au nanophasesrdquo Beilstein Journal of Nanotechnol-ogy vol 7 pp 22ndash31 2016

[24] M Yin M Liu and S Liu ldquoDevelopment of an alcoholsensor based on ZnO nanorods synthesized using a scalablesolvothermal methodrdquo Sensors and Actuators B Chemical vol185 pp 735ndash742 2013

[25] A Sirelkhatim S Mahmud A Seeni et al ldquoReview on zincoxide nanoparticles antibacterial activity and toxicity mecha-nismrdquo Nano-Micro Letters vol 7 no 3 pp 219ndash242 2015

[26] Y Zhang T R Nayak H Hong and W Cai ldquoBiomedicalapplications of zinc oxide nanomaterialsrdquo Current MolecularMedicine vol 13 no 10 pp 1633ndash1645 2013

[27] C Jaqadish and S J Pearton Zinc Oxide Bulk Thin Films andNanostructures Elsevier 2006

[28] T Yoshida D Komatsu N Shimokawa and H MinouraldquoMechanism of cathodic electrodeposition of zinc oxide thinfilms from aqueous zinc nitrate bathsrdquoThin Solid Films vol 451-452 pp 166ndash169 2004

[29] F Wang R Liu A Pan et al ldquoThe optical properties of ZnOsheets electrodeposited on ITO glassrdquoMaterials Letters vol 61no 10 pp 2000ndash2003 2007

[30] X D Gao X M Li and W D Yu ldquoRapid preparationcharacterization and photoluminescence of ZnO films by anovel chemicalmethodrdquoMaterials Research Bulletin vol 40 no7 pp 1104ndash1111 2005

[31] V R Shinde T PGujar andCD Lokhande ldquoStudies on growthof ZnO thin films by a novel chemical methodrdquo Solar EnergyMaterials amp Solar Cells vol 91 no 12 pp 1055ndash1061 2007

[32] J Wojnarowicz S Kusnieruk T Chudoba et al ldquoParam-agnetism of cobalt-doped ZnO nanoparticles obtained bymicrowave solvothermal synthesisrdquo Beilstein Journal of Nan-otechnology vol 6 pp 1957ndash1969 2015

[33] J Wojnarowicz R Mukhovskyi E Pietrzykowska S Kus-nieruk J Mizeracki and W Lojkowski ldquoMicrowave solvother-mal synthesis and characterization of manganese-doped ZnOnanoparticlesrdquo Beilstein Journal of Nanotechnology vol 7 pp721ndash732 2016

[34] S J Pearton D P Norton K Ip Y W Heo and T SteinerldquoRecent progress in processing and properties of ZnOrdquo Super-lattices and Microstructures vol 34 no 1-2 pp 3ndash32 2003

[35] Z Jiang T Xiao V L Kuznetsov and P P Edwards ldquoTurningcarbon dioxide into fuelrdquoPhilosophical Transactions of the RoyalSociety A vol 368 no 1923 pp 3343ndash3364 2010

[36] J Zhang C Wang R Chowdhury and S Adhikari ldquoSize-and temperature-dependent piezoelectric properties of galliumnitride nanowiresrdquo Scripta Materialia vol 68 no 8 pp 627ndash630 2013

[37] S Wang Z Cui and Y Xue ldquoSize-dependent thermodynamicproperties of the reaction of Nano- ZnO with benzoic acidrdquoNano vol 10 Article ID 1550104 7 pages 2015

[38] X F Wang Y L Fang T L Li and F J Wang ldquoSize-dependence of photoluminescence property of ZnO nanopar-ticlesrdquo Advanced Materials Research vol 887-888 pp 143ndash1462014

[39] W Promnopas T Thongtem and S Thongtem ldquoEffect ofmicrowave power on energy gap of ZnO nanoparticles synthe-sized by microwaving through aqueous solutionsrdquo Superlatticesand Microstructures vol 78 pp 71ndash78 2015


[40] L Irimpan V P N Nampoori P Radhakrishnan B Krishnanand A Deepthy ldquoSize-dependent enhancement of nonlinearoptical properties in nanocolloids of ZnOrdquo Journal of AppliedPhysics vol 103 no 3 Article ID 033105 2008

[41] S Lopes F Ribeiro J Wojnarowicz et al ldquoZinc oxide nanopar-ticles toxicity to Daphnia magna size-dependent effects anddissolutionrdquo Environmental Toxicology and Chemistry vol 33no 1 pp 190ndash198 2014

[42] L R Heggelund M Diez-Ortiz S Lofts et al ldquoSoil pH effectson the comparative toxicity of dissolved zinc non-nano andnanoZnO to the earthwormEisenia fetidardquoNanotoxicology vol8 no 5 pp 559ndash572 2014

[43] S Lee S Jeong D Kim S Hwang M Jeon and J Moon ldquoZnOnanoparticles with controlled shapes and sizes prepared using asimple polyol synthesisrdquo Superlattices and Microstructures vol43 no 4 pp 330ndash339 2008

[44] N Talebian S M Amininezhad and M Doudi ldquoControl-lable synthesis of ZnO nanoparticles and their morphology-dependent antibacterial and optical propertiesrdquo Journal ofPhotochemistry and Photobiology B Biology vol 120 pp 66ndash732013

[45] P Zhu J Zhang Z Wu and Z Zhang ldquoMicrowave-assistedsynthesis of various ZnO hierarchical nanostructures effectsof heating parameters of microwave ovenrdquo Crystal Growth andDesign vol 8 no 9 pp 3148ndash3153 2008

[46] P X Gao Y Ding and Z L Wang ldquoCrystallographicorientation-aligned ZnO nanorods grown by a tin catalystrdquoNano Letters vol 3 no 9 pp 1315ndash1320 2003

[47] X Y Kong Y Ding R S Yang and Z L Wang ldquoSingle-crystalnanorings formed by epitaxial self-coiling of polar nanobeltsrdquoScience vol 303 no 5662 pp 1348ndash1351 2004

[48] J Zhang L Sun C Liao and C Yan ldquoA simple route towardstubular ZnOrdquo Chemical Communications no 3 pp 262ndash2632002

[49] Y Zhang H Jia X Luo X Chen D Yu and R WangldquoSynthesis microstructure and growth mechanism of dendriteZnO nanowiresrdquo Journal of Physical Chemistry B vol 107 no33 pp 8289ndash8293 2003

[50] X Y Kong and Z L Wang ldquoSpontaneous polarization-induced nanohelixes nanosprings and nanorings of piezoelec-tric nanobeltsrdquo Nano Letters vol 3 no 12 pp 1625ndash1631 2003

[51] P X Gao and Z L Wang ldquoMesoporous polyhedral cages andshells formed by textured self-assembly of ZnO nanocrystalsrdquoJournal of the American Chemical Society vol 125 no 37 pp11299ndash11305 2003

[52] Z Petrovica M Ristica S Musica and M FabianbldquoNanomicrostructure and optical properties of ZnO particlesprecipitated from zinc acetylacetonaterdquo Journal of MolecularStructure vol 1090 pp 121ndash128 2015

[53] A-Q Zhang L Zhang L Sui D-J Qian and M ChenldquoMorphology-controllable synthesis of ZnO nano-micro-structures by a solvothermal process in ethanol solutionrdquoCrystal Research and Technology vol 48 no 11 pp 947ndash9552013

[54] M Jitianu and D V Goia ldquoZinc oxide colloids with controlledsize shape and structurerdquo Journal of Colloid and InterfaceScience vol 309 no 1 pp 78ndash85 2007

[55] A Kołodziejczak-Radzimska and T Jesionowski ldquoZinc oxide-from synthesis to application a reviewrdquoMaterials vol 7 no 4pp 2833ndash2881 2014

[56] K Byrappa andT Adschiri ldquoHydrothermal technology for nan-otechnologyrdquo Progress in Crystal Growth and Characterizationof Materials vol 53 no 2 pp 117ndash166 2007

[57] G J Demazeau ldquoSolvothermal reactions an original route forthe synthesis of novel materialsrdquo Journal of Materials Sciencevol 43 no 7 pp 2104ndash2114 2008

[58] W Lojkowski C Leonelli T Chudoba J Wojnarowicz AMajcher and AMazurkiewicz ldquoHigh-energy-low-temperaturetechnologies for the synthesis of nanoparticles microwaves andhigh pressurerdquo Inorganics vol 2 no 4 pp 606ndash619 2014

[59] A Majcher J Wiejak J Przybylski T Chudoba and J Woj-narowicz ldquoA novel reactor for microwave hydrothermal scale-up nanopowder synthesisrdquo International Journal of ChemicalReactor Engineering vol 11 no 1 pp 361ndash368 2013

[60] P W Dunne A S Munn C L Starkey and E H LesterldquoThe sequential continuous-flow hydrothermal synthesis ofmolybdenum disulphiderdquo Chemical Communications vol 51no 19 pp 4048ndash4050 2015

[61] P W Dunne C L Starkey A S Munn et al ldquoBench-and pilot-scale continuous-flow hydrothermal production ofbarium strontium titanate nanopowdersrdquoChemical EngineeringJournal vol 289 pp 433ndash441 2016

[62] P W Dunne A S Munn C L Starkey T A Huddle and E HLester ldquoContinuous-flow hydrothermal synthesis for the pro-duction of inorganic nanomaterialsrdquo Philosophical Transactionsof the Royal Society A Mathematical Physical and EngineeringSciences vol 373 no 2057 Article ID 20150015 2015

[63] M Gimeno-Fabra F Hild P W Dunne et al ldquoContinuoussynthesis of dispersant-coated hydroxyapatite platesrdquoCrystEng-Comm vol 17 no 32 pp 6175ndash6182 2015

[64] J Lai W Niu R Luque and G Xu ldquoSolvothermal synthesis ofmetal nanocrystals and their applicationsrdquo Nano Today vol 10no 2 pp 240ndash267 2015

[65] G Demazeau ldquoSolvothermal reactions an opening-up onthe synthesis of novel materials or the development of newprocessesrdquo High Pressure Research vol 27 no 1 pp 173ndash1772007

[66] M Niederberger and N Pinna Metal Oxide Nanoparticles inOrganic Solvents Synthesis Formation Assembly and Appli-cation Springer Science amp Business Media Berlin Germany2009

[67] B W Chieng and Y Y Loo ldquoSynthesis of ZnO nanoparticles bymodified polyol methodrdquo Materials Letters vol 73 pp 78ndash822012

[68] J Lian Y Liang F-L Kwong Z Ding and D H L NgldquoTemplate-free solvothermal synthesis of ZnO nanoparticleswith controllable size and their size-dependent optical proper-tiesrdquoMaterials Letters vol 66 no 1 pp 318ndash320 2012

[69] H Wang C Xie and D Zeng ldquoControlled growth of ZnO byadding H

2Ordquo Journal of Crystal Growth vol 277 no 1ndash4 pp

372ndash377 2005[70] M Bitenc andZCrnjakOrel ldquoSynthesis and characterization of

crystalline hexagonal bipods of zinc oxiderdquo Materials ResearchBulletin vol 44 no 2 pp 381ndash387 2009

[71] S Li S Meierott and J M Kohler ldquoEffect of water content ongrowth and optical properties of ZnO nanoparticles generatedin binary solventmixtures bymicro-continuous flow synthesisrdquoChemical Engineering Journal vol 165 no 3 pp 958ndash965 2010

[72] J Wang C Loose J Baxter et al ldquoGrowth promotion by H2O

in organic solventmdashselective isolation of a target polymorphrdquoJournal of Crystal Growth vol 283 no 3-4 pp 469ndash478 2005


[73] E MWong J E Bonevich and P C Searson ldquoGrowth kineticsof nanocrystalline ZnO particles from colloidal suspensionsrdquoThe Journal of Physical Chemistry B vol 102 no 40 pp 7770ndash7775 1998

[74] E M Wong P G Hoertz C J Liang B-M Shi G J Meyerand P C Searson ldquoInfluence of organic capping ligands on thegrowth kinetics of ZnOnanoparticlesrdquo Langmuir vol 17 no 26pp 8362ndash8367 2001

[75] Z Hu G Oskam and P C Searson ldquoInfluence of solvent on thegrowth of ZnO nanoparticlesrdquo Journal of Colloid and InterfaceScience vol 263 no 2 pp 454ndash460 2003

[76] Z Hu G Oskam R L Penn N Pesika and P C SearsonldquoThe influence of anion on the coarsening kinetics of ZnOnanoparticlesrdquo Journal of Physical Chemistry B vol 107 no 14pp 3124ndash3130 2003

[77] N S Pesika K J Stebe andPC Searson ldquoRelationship betweenabsorbance spectra and particle size distributions for quantum-sized nanocrystalsrdquo Journal of Physical Chemistry B vol 107 no38 pp 10412ndash10415 2003

[78] E Hosono S Fujihara T Kimura and H Imai ldquoGrowthof layered basic zinc acetate in methanolic solutions and itspyrolytic transformation into porous zinc oxide filmsrdquo Journalof Colloid and Interface Science vol 272 no 2 pp 391ndash398 2004

[79] A Opalinska C Leonelli W Lojkowski et al ldquoEffect ofpressure on synthesis of Pr-doped zirconia powders producedby microwave-driven hydrothermal reactionrdquo Journal of Nano-materials vol 2006 Article ID 98769 8 pages 2006

[80] httpscience24comfw145m[81] A Clearfield J Reibenspies and N Bhuvanesh Principles and

Applications of Powder Diffraction Wiley-Blackwell 2008[82] K Venkateswarlu D Sreekanth M Sandhyarani V Muthu-

pandi A C Bose and N Rameshbabu ldquoX-ray peak profileanalysis of nanostructured hydroxyapatite and fluorapatiterdquoInternational Journal of Bioscience Biochemistry and Bioinfor-matics vol 2 pp 389ndash393 2012

[83] R Pielaszek ldquo1198651198821545119872 method for determination of thegrain size distibution form powder diffraction line profilerdquoJournal of Alloys and Compounds vol 382 no 1-2 pp 128ndash1322004

[84] httpscience24comxrd[85] S Tamari and A Aguilar-Chavez ldquoOptimum design of the

variable-volume gas pycnometer for determining the volume ofsolid particlesrdquoMeasurement Science andTechnology vol 15 no6 pp 1146ndash1152 2004

[86] K Heister ldquoThe measurement of the specific surface area ofsoils by gas and polar liquid adsorption methods-limitationsand potentialsrdquo Geoderma vol 216 pp 75ndash87 2014

[87] T Wejrzanowski R Pielaszek A Opalinska H Matysiak WŁojkowski and K J Kurzydłowski ldquoQuantitative methods fornanopowders characterizationrdquo Applied Surface Science vol253 no 1 pp 204ndash208 2006

[88] W Pabst and E Gregorova Characterization of Particles andParticle Systems Institute of Chemical Technology in PraguePrague Czech Republic 2007

[89] S J Gregg and K S W Sing Adsorption Surface Area andPorosity Academic Press London UK 2nd edition 1982

[90] D Smolen T Chudoba S Gierlotka et al ldquoHydroxyapatitenanopowder synthesis with a programmed resorption raterdquoJournal of Nanomaterials vol 2012 Article ID 841971 9 pages2012

[91] A Opalinska I Malka W Dzwolak T Chudoba A Presz andW Lojkowski ldquoSize-dependent density of zirconia nanoparti-clesrdquo Beilstein Journal of Nanotechnology vol 6 no 1 pp 27ndash352015

[92] X Yu and Z Zhan ldquoThe effects of the size of nanocrystallinematerials on their thermodynamic and mechanical propertiesrdquoNanoscale Research Letters vol 9 no 1 article 516 pp 1ndash6 2014

[93] F Hai-Bo Z Xin-Liang W Si-Cheng L Zhi-Gang and Y He-Bao ldquoZnO ratio and oxygen chemical state of nanocrystallineZnO films grown at different temperaturesrdquo Chinese Physics Bvol 21 no 3 Article ID 038101 5 pages 2012

[94] D Sibera R Jędrzejewski J Mizeracki A Presz U Narkiewiczand W Łojkowski ldquoSynthesis and characterization of ZNOdoped with Fe

2O3mdashhydrothermal Synthesis and Calcination

Processrdquo Acta Physica Polonica A vol 116 pp S133ndashS135 2009[95] S Bhasha P Malik S Santosh and J Purnima ldquoSynthesis and

characterization of nanocrystalline zinc oxide thin films forethanol vapor sensorrdquo Nanomedicine Nanotechnology Journalsvol 6 article 306 2015

[96] F Varenne A Makky M Gaucher-Delmas F Violleau and CVauthier ldquoMultimodal dispersion of nanoparticles a compre-hensive evaluation of size distribution with 9 size measurementmethodsrdquoPharmaceutical Research vol 33 pp 1220ndash1234 2016

[97] M Baghbanzadeh S D Skapin Z C Orel and C O Kappe ldquoAcritical assessment of the specific role of microwave irradiationin the synthesis of ZnO micro- and nanostructured materialsrdquoChemistrymdashA European Journal vol 18 no 18 pp 5724ndash57312012

[98] J S Schanche ldquoMicrowave synthesis solutions from personalchemistryrdquoMolecular Diversity vol 7 no 2 pp 291ndash298 2003

[99] J Wojnarowicz T Chudoba D Smolen W Łojkowski AMajcher and A Mazurkiewicz ldquoExamples of the nanoparticlesproduced by microwave solvothermal synthesis (MSS) routerdquoGlass and Ceramics vol 65 pp 8ndash11 2014

[100] P Tonto O Mekasuwandumrong S Phatanasri V PavarajarnandP Praserthdam ldquoPreparation of ZnOnanorod by solvother-mal reaction of zinc acetate in various alcoholsrdquo CeramicsInternational vol 34 no 1 pp 57ndash62 2008

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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layers are also applied as transparent conductive materialsnanostructured electrodes for batteries and components ofdevices with acoustic surface wave [28ndash31] After doping itdisplays new for example paramagnetic ferromagnetic andmagnetooptical properties [10 16 32ndash34] It is widely used asa component of various products such as rubber pigmentscements plastics sealants and paints It is also a componentof pharmaceutical products and cosmetics for example babypowders toothpastes and tooth dressings sunscreens andskin protection balms It is used as a catalyst in organicreactions for example for synthesis of methanol from CO

2

and H2[35]

The properties of ZnO nanostructures are stronglydependent on their size and shape Youngrsquos modulus of ZnOnanowires changes considerably when the shape of theircross section changes [36] The size of ZnO particles exertsa considerable impact above all on the equilibrium constantand the thermodynamic properties of the reaction [37]photoluminescence [38] band gap [39] UV absorption [40]and toxicity [41 42] Particularly piezoelectric parametersmay be greater by several orders of magnitude in comparisonwith ZnO bulk material [36] As a result such methods ofnano-ZnO synthesis are needed that enable a precise controlof the average particle size and obtaining a narrow sizedistribution In order to obtain the required performancecharacteristics it is also necessary that the material is fullycrystalline and characterised by high purity

The relevant literature includes numerous chemicalphysical and biological methods of producing ZnO nanos-tructures of different shapes for example spherical [4344] straw bundle wide chrysanthemum nanorod-basedmicrospheres [45] nanowires [46] nanobelts [47] columns[48] tetrapods [49] helices [50] polyhedral cages and shells[51] tubes rods and needles [43 44 52] flowers [44 53]and irregular crystals and spherical to hexagonal prisms [54]The most often employed laboratory methods of obtainingZnO NPs are calcination precipitation sol-gel electrolyticobtaining and hydrothermal and solvothermal synthesis[55] Microwave hydrothermal and solvothermal synthesiscount as ones of the most popular methods of obtainingnanomaterials [56 57] They are systematically developed byconstructing new types of reactors for example stop-flowand continuous-flow ones [58ndash63]

Syntheses ofmetal oxide nanoparticles in organic solventshave been very popular recently [64ndash66] The main reasonsfor choosing organic solvents in the synthesis of nano-ZnO are nucleation and growth of nanoparticles in highboiling polyols such as ethylene glycol (EG) diethyleneglycol (DEG) tetraethylene glycol (TEG) or glycerol Inthis case the polyol acts as the solvent and the stabilisingagent which restricts particle growth and suppresses particleagglomeration and aggregation Organic solvents also enableobtaining uniformly doped ZnONPs for example with Co2+or Mn2+ions without precipitation of foreign phases [32 33]In addition the synthesis is easy to perform and does notrequiremultistage steps or advanced experimental conditionsor professional reactors

The relevant literature offers several methods of control-ling the size of ZnO NPs obtained in solvothermal synthesis

that is in organic solvents Chieng and Loo [67] described asingle-stage synthesis with control of ZnO NPs size whereas the reaction precursors they used solutions obtained bydissolving Zn(CH

3COO)

2sdot2H2O in EG DEG and TEGThe

average size of the obtained ZnO NPs in EG was 20 nm inDEG 39 nm and in TEG 69 nmThe size control of ZnONPswas explained by the authors with the impact of the chainlength of the polyols used The average particle size of ZnOwas increased in line with the increased glycol chain lengthLian et al in their paper [68] described a synthesis of ZnONPs with controllable size via a solvothermal method usinga mixed solvent system The average size of the NPs can betailored within the range from 15 nm to 25 nm by adjustingthe volume ratio of ethanolEGWang et al [69] were ones ofthe first scholars to describe the solvothermal synthesis withcontrolled size of ZnO microstructures by adding water tothe organic solvent A solution of zinc acetate dissolved inmethanol was used as the reaction precursor However ZnOmicrostructures obtained in that manner contained foreignphases and were heterogeneous Wang suggested that themechanism of ZnO size control by changing theH

2O content

in the precursor was the probable impact of water on thesimultaneous course of hydrolysis of Zn(CH

3COO)

2as well

as of the generated intermediates Bitenc and Crnjak Orel[70] described a one-step solution phase preparationmethodused for the preparation of nano- and submicrometre-sizedZnO As the reaction precursor they used a mixture ofZn(NO

3)2sdot6H2Oand urea in solventsThe paper shows a syn-

thesis of ZnO structures which can be controlled by changingthe types of solvents water and waterpolyol where a partof the water is substituted with EG DEG and TEG It wasindicated in the example of EG that the size of the structuresdecreased in line with increasing volumeconcentration ofthe added EG The publication by Li et al [71] is anotherone which confirms the possibility of controlling the size ofZnO NPs by changing water concentration in the precursorsuspension obtained by mixing Zn(CH

3COO)

2+ NaOH

+ tetradecane in EG The authors obtain ZnO NPs by amultistage method within the size range between 18 nmand 436 nm However based on the provided results thephase purity of all obtained samples of ZnO NPs cannot beconfirmed

It was determined that water exerts a significant impacton the course of solvothermal synthesis and even smallamounts of H

2O in organic solvents promote crystal growth

[72] However papers of most scholars do not take intoaccount the presence and changes in the concentration ofwater in the precursor despite the fact that water is suppliedto the precursor in two ways with a hydrated salt forexample Zn(CH

3COO)

2sdot2H2O and togetherwith an organic

solvent wherein it occurs in trace quantities [67 68] Themechanism of growth and size control of ZnO crystals inorganic solvents has not been unambiguously explained sofar [73ndash77] It should be remembered that each mechanismof ZnO synthesis should be treated individually This resultsfrom the diversity of precursors used and at the same timefrom the multitude of obtainable intermediates belonging tothe group of metalorganic compounds [78]





2sdot






2O)




(CH3CO2)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP






119863

ℎ119896119897=

119870 sdot 120582

120573 sdot cos 120579ℎ119896119897

(2)



1205721

radiation) 120579ℎ119896119897






(a) (b)



Reactor

Antenna

WaveguideMagnetron


(regulation set)

Remotecontroller

(c)



3COO)

2sdot2H2O which was


Sample 119862119901H2O[wt]



119863 =

119873 sdot 1000

SSA sdot 120588 (3)








100nm

(a)

100nm

(b)

100nm

(c)

100nm

(d)

100nm

(e)


200nm

(a)

200nm

(b)

200nm

(c)

200nm

(d)

200nm

(e)






50nm

(a)

50nm

(b)

50nm

(c)

100 nm

(d)

100 nm

(e)







2120579 (∘) Intensity ℎ 119896 119897

31728 578 1 0 034400 442 0 0 236212 999 1 0 147494 229 1 0 256519 324 1 1 062803 276 1 0 366283 44 2 0 067866 243 1 1 268992 114 2 0 172516 19 0 0 476860 38 2 0 281315 19 1 0 489500 74 2 0 3








16330


10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)


2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)


2O (c) 4 H

2O









Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







2sdot






2O)




(CH3CO2)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP






119863

ℎ119896119897=

119870 sdot 120582

120573 sdot cos 120579ℎ119896119897

(2)



1205721

radiation) 120579ℎ119896119897






(a) (b)



Reactor

Antenna

WaveguideMagnetron


(regulation set)

Remotecontroller

(c)



3COO)

2sdot2H2O which was


Sample 119862119901H2O[wt]



119863 =

119873 sdot 1000

SSA sdot 120588 (3)








100nm

(a)

100nm

(b)

100nm

(c)

100nm

(d)

100nm

(e)


200nm

(a)

200nm

(b)

200nm

(c)

200nm

(d)

200nm

(e)






50nm

(a)

50nm

(b)

50nm

(c)

100 nm

(d)

100 nm

(e)







2120579 (∘) Intensity ℎ 119896 119897

31728 578 1 0 034400 442 0 0 236212 999 1 0 147494 229 1 0 256519 324 1 1 062803 276 1 0 366283 44 2 0 067866 243 1 1 268992 114 2 0 172516 19 0 0 476860 38 2 0 281315 19 1 0 489500 74 2 0 3








16330


10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)


2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)


2O (c) 4 H

2O









Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(a) (b)



Reactor

Antenna

WaveguideMagnetron


(regulation set)

Remotecontroller

(c)



3COO)

2sdot2H2O which was


Sample 119862119901H2O[wt]



119863 =

119873 sdot 1000

SSA sdot 120588 (3)








100nm

(a)

100nm

(b)

100nm

(c)

100nm

(d)

100nm

(e)


200nm

(a)

200nm

(b)

200nm

(c)

200nm

(d)

200nm

(e)






50nm

(a)

50nm

(b)

50nm

(c)

100 nm

(d)

100 nm

(e)







2120579 (∘) Intensity ℎ 119896 119897

31728 578 1 0 034400 442 0 0 236212 999 1 0 147494 229 1 0 256519 324 1 1 062803 276 1 0 366283 44 2 0 067866 243 1 1 268992 114 2 0 172516 19 0 0 476860 38 2 0 281315 19 1 0 489500 74 2 0 3








16330


10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)


2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)


2O (c) 4 H

2O









Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




100nm

(a)

100nm

(b)

100nm

(c)

100nm

(d)

100nm

(e)


200nm

(a)

200nm

(b)

200nm

(c)

200nm

(d)

200nm

(e)






50nm

(a)

50nm

(b)

50nm

(c)

100 nm

(d)

100 nm

(e)







2120579 (∘) Intensity ℎ 119896 119897

31728 578 1 0 034400 442 0 0 236212 999 1 0 147494 229 1 0 256519 324 1 1 062803 276 1 0 366283 44 2 0 067866 243 1 1 268992 114 2 0 172516 19 0 0 476860 38 2 0 281315 19 1 0 489500 74 2 0 3








16330


10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)


2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)


2O (c) 4 H

2O









Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




50nm

(a)

50nm

(b)

50nm

(c)

100 nm

(d)

100 nm

(e)







2120579 (∘) Intensity ℎ 119896 119897

31728 578 1 0 034400 442 0 0 236212 999 1 0 147494 229 1 0 256519 324 1 1 062803 276 1 0 366283 44 2 0 067866 243 1 1 268992 114 2 0 172516 19 0 0 476860 38 2 0 281315 19 1 0 489500 74 2 0 3








16330


10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)


2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)


2O (c) 4 H

2O









Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials








16330


10nm

(a)

10nm

(b)

10nm

(c)

10nm

(d)

10nm

(e)


2O (c) 2 H

2O (d) 3 H

2O (e) 4 H

2O

(a) (b) (c)


2O (c) 4 H

2O









Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials











Inte

nsity

(cou

nts)

ZnO (1)

ZnO (15)

ZnO (2)

ZnO (3)

ZnO (4)

20 30 40 50 60 70 80 90102120579 (∘)

ZnO (JCPDS 36-1451)


ac


52045

52050

52055

52060

52065

52070

Latti

ce p

aram

eter

c(Aring

)

32490

32495

32500

32505

32510

32515

Latti

ce p

aram

eter

a(Aring

)



119888119889





20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)




2O [91]




2NPs and






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






119904plusmn 120590 (m2g)


pycnometry120588

119904plusmn 120590 (gcm3)


BET 119889 plusmn 120590 (nm)





119886 119889119888(nm)


formula 119889119888119889

119886






Inte

nsity

(cou

nts)











0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





0

10

20

30

40

Cou

nts

Lognormal

w = 027 plusmn 001 A = 583 plusmn 20

1205942DoF = 360467R2 = 0990


(a)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 029 plusmn 002A = 1030 plusmn 63

1205942DoF = 1871R2 = 0964


(b)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0299 plusmn 001A = 1072 plusmn 40

1205942DoF = 7357R2 = 0987


(c)

0

10

20

30

40

50

60

70C

ount

s


Lognormal

w = 0222 plusmn 0008A = 999 plusmn 30

1205942DoF = 5162R2 = 0989


(d)


0

10

20

30

40

50

60

Cou

nts

Lognormal

w = 0525 plusmn 003A = 3949 plusmn 188

1205942DoF = 11175R2 = 0973

y0 = 05xc = 657 plusmn 21

(e)


2O (c) 2 H

2O (d) 3 H

2O and (e) 4 H

2O








2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










2sdot


2O

in ethylene glycol



(CH3COO)

2Zn sdot 2H

2O

H2O


2O + CH

3COOminus (4)


2O + 5CH

3COOminus TP

997888997888rarr Zn5(OH)8(CH3COO)

2sdot 2H2O + 8CH

3COOH (5)

Zn5 (OH)8 (CH3COO)


darr+ 2CH

3COOH + 5H

2O (6)

CH3COOH + C

2H4 (OH)2

TP997888997888rarr CH

3COOC

2H4OH +H

2O (7)

(CH3COO)

2Zn sdot 2H

2O

C2H4(OH)2H2OTP


3COOC

2H4OH + CH

3COOH (8)


3COO)



3COO)





3COO)Zn+sdot2H






y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




y = 823x + 1627

20

25

30

35

40

45

50

55

Aver

age p

artic

le si

ze fr

om S

SA (n

m)


R2 = 09721


SSADensity

20

25

30

35

40

45

50

Spec

ific s

urfa

ce ar

ea (m

2 g)


527529531533535537539541543545

Den

sity

(gc

m3 )



3COO)





2O and synthesis




3COO)



Competing Interests


Acknowledgments


References























































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



research article effect of water content in ethylene...

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