research article transparent nanocrystallite silver...

Hindawi Publishing CorporationJournal of NanomaterialsVolume 2013 Article ID 901452 6 pageshttpdxdoiorg1011552013901452

Research ArticleTransparent Nanocrystallite Silver for Antibacterial Coating

W Ahliah Ismail Zainal Abidin Ali and R Puteh

Corrosion and Coating Laboratory Physics Department Universiti Malaya 50603 Kuala Lumpur Malaysia

Correspondence should be addressed to Zainal Abidin Ali zaba 87yahoocom

Received 18 March 2013 Revised 27 May 2013 Accepted 27 May 2013

Academic Editor WilliamW Yu

Copyright copy 2013 W Ahliah Ismail 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

Transparent sol-gel film with antibacterial coating property incorporating silver nanoparticles has been successfully developedSilver nanoparticles were synthesized by precipitation method at room temperature XRD structural studies show that crystallitesizes in the range of 18 nm to 40 nm were produced The coating system used methyltrimethoxy silane as binder and N-propanolas diluent to obtain the highest transperancy 25 wt of nanosilver crystallites was added as antibacterial agent The coatingmixture was applied onto glass plates using sponges and tested against Staphylococcus aureus Escherichia coli and Pseudomonasaeruginosa Values of antimicrobial activity of 46 72 and 42 were respectively obtained for Staphylococcus aureus Escherichiacoli and Pseudomonas Aeruginosa Coating with antimicrobial activity greater than 2 classified as antibacterial

1 Introduction

Antibacterial is an important branch of functional coatingthat plays an important role not only for general hygiene butalso for saving life as disinfectant in places such as operationtheatre in hospitals Antibacterial studies are mostly evolvedaround Staphylococcus aureus [1] Escherichia coli [2] andPseudomonas aeruginosa [3] Staphylococcus aureus is fre-quently found in human respiratory tract and skin It is acommon cause of skin infections respiratory disease andfood poisoning On the other hand Escherichia coli is com-monly found in lower intestine of warm blooded organism Itusually causes the food poisoning and is occasionally respon-sible for product recalls due to food contaminationThe thirdbacteria Pseudomonas Aeruginosa is considered as one of thetoughest bacterial strain and able to survive in harsh environ-ments It does not usually cause illness to healthy people butit is described as an opportunistic organism causing seriousinfectionwhen our normal defences systemweakened It rep-resents a great threat to the most vulnerable hospital patientsfor example intensive care patients those with depletedimmune system such as cancer patients people with seriousburn and premature babies in neonatal units

There is enormous interest in the research of highly effi-cient and low-cost antibacterial surface treatments to avoid

the breeding and spreading of the harmful microorganisms[4 5] Most of the approaches for achieving antibacterialsurfaces are based on silver particles [6ndash9]The silver particlesprovide ionswhich are highly toxic to bacteriaThe advantageof silver as antibacterial agent is the selective toxicity to awiderange of microorganism Over the years studies have shownthat the miniaturization of silver particles has significantlyimproved the performance as antibacterial agent [2 6]Nano-particles with higher specific area are more efficient in releas-ing silver ions Sol gel is one of the methods used to incorpo-rate silver nanoparticles in the coating It has several advan-tages such as high purity homogeneity and low processingtemperatures Since sol is usually applied to the surface bydip coating or spin coating this limits the application of thecoatings to only small size materials or substrates as dip orspin coater is unable to accommodate bigger material Thusthe coater itself becomes a limiting factor in the antibacterialapplications

Therefore in this work we would like to report the anti-bacterial behaviour of our transparent coating against Staphy-lococcus aureus Escherichia coli and Pseudomonas aerugi-nosa in which the sol was applied using only a sponge Nodip or spin coater was used The coating has been preparedaccording to our previous work [10] where the details on thecoating properties are available

2 Journal of Nanomaterials

For antibacterial activity measurement it is a commonprocedure to carry out the test according to Japanese Indus-trial Standard JIS Z 2801 This method was developed tomeasure the antibacterial activity in hydrophobic materialsoriginally resulting from the incorporation of silver ions intorigid polymers Developed by a consortium of workers com-prised of manufacturers of silver-based antimicrobial agentsgovernment-based research organisations and universitiesunder the organisation of the Society of Industrial technologyfor Antimicrobial Articles (SIAA) the method has then beenvalidated by ring tests within Japan [11] and now forms thebasis of a draft ISO standard which is being validated by theSIAA in collaborationwith the International BiodeteriorationResearch Group (IBRG [12]) In JIS Z 2801 the antibacterialactivity is measured by quantifying the survival of bacterialcells which have been held in intimate contact for 24 hours at35∘C with a surface that contains an antibacterial agent Theantibacterial property is measured by comparing the survivalof bacteria on a treated material with that achieved on anuntreated material

2 Experimental Method

21 Nanosilver Crystal Precipitation Silver nanocrystals wereprepared according to the method reported in [13] 20mL ofethylene diamine was added into the silver nitrate solutionand stirred for 5minutes Cetyltrimethylammoniumbromide(CTAB) was added to the solution as a dispersing agent andstirred vigorously for another 5minutes before adding hydra-zine hydrate The solution was stirred and kept at the roomtemperature for 15minutesTheparticleswere separated fromthe solution by centrifuging the solution at 5000 rpm for 20minutesThe particles were washed from the reactants chem-icals by repeating the centrifuging process with deionisedwater and lastly with ethanol The particles gathered weredried in desiccators for 24 hrs Ball milling process withweight ratio of ball to sample 120 1 was carried out for 4hours at 300 rpm The milled particles were characterisedusing XRD to confirm the crystal structure and estimate thecrystallite size

22 Preparation of Coating Mixture for Antibacterial Test-ing N-propanol and methyltrimethoxy silane (SindashCH

3ndash

(OCH3)3) wasmixed in a beaker with the ratio of 1 1 25wt

of silver nanocrystal was added into the system and wasgrinded in the ball mill for 1 hr Nitric acid was diluted toobtain the pH of 01 and was used as catalyst (10wt) Thecoating process was carried out in room temperature of26∘C and absolute humidity 30 These two factors werekept constant throughout the experiment The dried sampleswere measured for transparency using haze meter with D65illumination light at room temperature and surface qualitywas evaluated using a microscope with 500x maximummagnification

23 Antibacterial Activity Test The dried sample was testedagainst Staphylococcus aureus Escherichia coli and Pseudo-monasAeruginosa according to JIS Z 2801200 (Antimicrobial

20 30

[111][200] [220] [311]

40 50 60 70 80 90 100

XRD peaks for all the samples

06M05M04M03M02M01M

Figure 1 XRD pattern of silver particles produced with varioussilver nitrate molarity

product test for antimicrobial activity and efficacy) by anaccredited testing lab (SIRIM QAS International Sdn Bhd)This ensures and guarantees reliability accuracy and validityof the results

As reported by [11ndash13] the testmicroorganism is preparedby growth in a liquid culture medium The suspension oftest microorganism is standardized by dilution in a nutritivebroth (this affords microorganisms the potential to growduring the test) Control and test surfaces are inoculated with04mL of the germ suspension in triplicate Then the inocu-lum is covered with a film to prevent the evaporation of thesuspension and to ensure close contact with the samples sur-face Immediately after inoculation the bacteria from the ref-erence sample are separated from the sample surfaces and thenumber of viable germs is determined (119905

0value) by elution

followed by dilution and plating The other samples (11990524) are

allowed to incubate in a humid environment for 24 hoursAfter incubation microbial concentrations are determinedby elution followed by dilution and plating Activityefficacyis calculated by comparing the germ concentration after 24hours relative to concentration of the blank sample after 24hours

3 Result and Discussion

31 Structural Study and Determination of Crystallite SizeThe chemical route for the formation of silver nanoparticlescan be described as follows [14]

Ag+ + (CH2NH2)2

997888rarr [Ag(CH2NH2)2

]+ (1)

4[Ag(CH2NH2)2

]+

+ 5N2H4

997888rarr 4Ag + 4N2H5+ N2+ 4 (CH

2NH2)

(2)

In (1) the first reaction of Ag+ with the ethylenediamine isto form the [Ag (CH

2NH2)2]+ complex and the following

reaction in (2) with the hydrazine hydrate to form silvermetal CTAB was added to disperse the particles formedThesilver precipitate produced was structurally analysed by XRDfrom 5∘ to 90∘ 2120579 angle (Figure 1)The same peaks appeared inall of the samples and after fitting and it is confirmed that thecrystal consists of silver atoms only There was no evidenceof oxygen or other atoms existed in the crystal structure Thecrystals formed are face-centered cubic structure

Journal of Nanomaterials 3

Table 1 The antibacterial efficacy against Pseudomonas aeruginosa Escherichia coli and Staphylococcus aureus

Bacteria species Sample Number of viable cells ofbacteria at 0 hr

Number of viable cells ofbacteria after 24 hrs

Value of antimicrobialactivity

Pseudomonas aeruginosa 25 silver coatinglowast 18 times 105

20 times 102

46

Controllowastlowast 19 times 105

95 times 106 mdash

Escherichia coli 25 silver coating 40 times 105

lt10 72

Control 44 times 105

17 times 108 mdash

Staphylococcus aureus 25 silver coating 20 times 105

89 times 102

42


15 times 107 mdash

lowast

25 silver coating coating consists of silver and sol-gel formulationlowastlowastControl glass slides with no coating applied

Table 2 The antibacterial tests against Pseudomonas aeruginosa Escherichia coli and Staphylococcus aureus on glass slides that were coatedonly with sol gel without any Ag nanoparticles




Pseudomonas aeruginosa Sol-gel-coated slidelowast 20 times 105

36 times 107 mdash


95 times 106 mdash

Escherichia coli Sol-gel-coated slide 46 times 105

11 times 108 mdash


17 times 108 mdash

Staphylococcus aureus Sol-gel-coated slide 20 times 105

15 times 107 mdash


15 times 107 mdash

lowastSol-gel-coated slide coating consists only sol gel no Ag silverlowastlowastControl glass slides with no coating applied

398361

188 186 188

380

05

101520253035404550

Crys

talli

te si

ze (n

m)

Molarity (M)060504030201

Figure 2 Variation of crystallite size with silver nitrate molarity

Estimation of silver crystallite size was made throughLorentzian curve fit to the strongest peak in the XRD patternAg [111] which is from 37∘ to 42∘ XRD testing was repeatedfor all the samples zoomed in at the angle of 2120579 from37∘ to 42∘120573 and 120579 of every sample were determined from the peak andthrough Scherrer Equation the crystallite size of the sampleswas calculated and shown in Figure 2

From Figure 2 it clearly shows that at the molarity of03M to 05M the crystallite size was the smallest Size of thesilver crystals formed is one of the most important factors indetermining the antibacterial efficiency of the silver to fightthe microbes This is attributed to the high surface area tovolume ratio and the quantum confinement effect caused byextremely reduced size (ie electron confinement in a smallarea) [15] The nanocrystallite silver that was synthesisedfrom 03M was then used for the antibacterial testing

32 Antibacterial Test Result Figure 3 shows three glass sur-faces that have been applied with the antibacterial coatingSlide A was the uncoated glass whereas slide B and C bothwere coated with 25 and 35 of Ag The coating wastransparent The presence of Ag nanoparticles powder isvisible on the surface when the slides were tilted to a certainangle (Figure 3(b)) As has been reported [12] the haze valuefor 25 was 342

Figure 4 compares the transparency of the slides opti-cally The transparency level decreases as the amount of Agincreases from 25 to 35 As the coating was purposelydeveloped for surface treatment it should cause onlyminimaleffect to the applied surface in term of colour and level ofhaziness

The results for antibacterial test against Staphylococcusaureus Escherichia coli and Pseudomonas Aeruginosa accord-ing to JIS Z 2801 (antimicrobial product test for antimicrobialactivity and efficacy) of the coating are shown in Table 1

Coating with antimicrobial activity greater than 2 is class-ified as antibacterial The antibacterial test result clearlyshows value of antimicrobial activity of 46 for PseudomonasAeruginosa 72 for Escherichia coli and 42 for Staphylococcusaureus All the values exceeded that of value 2 which con-firmed the antibacterial coating and therefore comply withthe standard of JIS Z 2801

In order to verify that the antibacterial properties comeonly from the Ag nanoparticles and not from the sol-gelformulation we carried out antibacterial tests to slides coatedwith only the sol gel (no Ag nanoparticles were used) Thenoncoated slides were used as controls The results in Table 2


(a) (b)

Figure 3 A transparent antibacterial coating applied onto a glass surface (a) and (b) slide-A-uncoated surface slide-B-Ag 25-coatedsurface and slide-C-Ag 35-coated surface

(a) (b)

(c)

Figure 4 Optical comparison of transparency level by placing the slides approximately 2 cm in front of the lense of digital camera (a) slideA-noncoated (b) slide B-25 Ag and (c) slide C-35 Ag

show that the number of bacterial is increased after 24 hoursfor all types of bacteria for the sol-gel-coated slides Thisverifies and proves that the sol gel does not kill and thus hasno antibacterial properties

Antibacterial nanocrystallite silver may work in twoways firstly it breaks through the permeability of outermembrane resulting in the leakage of cellular materials It is

well known that bacteria possess an outer membrane to serveas a selective permeability barrier which protects bacteriafrom harmful agents such as detergents drugs toxins anddegradative enzymes and penetrating nutrients to sustainbacterial growth Kim et al [16] reported studies based on Saureus and E coli that the free radicals could induce bacterialcell membrane damage by enhancing the permeability of


themembraneThe bacteria will then undergo a protein leak-age as a result of the increasing membrane permeability

Secondly as a result of the increasing permeability nano-crystallite silver can enter the inner membrane and inactivaterespiratory chain dehydrogenases thus inhibiting respirationand growth of cells Holt and Bard proved this by showingthat Ag+ can inhibit the respiration of E coli by determiningchange of oxygen dissolved in culture resolution [17] Areport [18] on Pseudomonas aeruginosa also suggested thatsilver nanoparticles not only inhibited the growth but also theability of the organism to synthesize the exopolysaccharideThe exopolysaccharide functions not only to protect thebacteria from the host defense mechanism but also mediatethe adhesion of the organism to the surface At the same timethe silver could as well affect some proteins and phosphatelipids and induce collapse of membrane resulting in celldecomposition and death eventually This is supported byKim et al [19] who found that Ag+ interactedwith thiol (ndashSH)group of cysteine by replacing the hydrogen atom to formndashSndashAg thus hindering the enzymatic function of affected proteinto inhibit growth of E coli

Themost attractive aspects of this work are the simplicityof the coating method and its effectiveness in killing thebacteria As has been reported the coating was applied usingonly a melamine sponge which means that everybody coulduse it No special expertise is required Moreover it wouldprovide a simple and cheaper way for medical rooms andfacilities (eg wall floor and table) to be bacterial-freeenvironment anytime required

4 Conclusion

We managed to develop an antimicrobial coating layer thatis very easy to apply and dry in the room temperature Thecoating is very transparent clear and will not change theoriginal property of the substrate It is very suitable for thewindow glasses wall and floor coatingThe best formulationwas obtained from formulation 1 1 ratio ofmethyltrimethoxysilane to N-propanol The coating shows the antibacte-rial activity to gram-positive (Pseudomonas Aeruginosa andEscherichia coli) and gram-negative (Staphylococcus aureus)bacteria strain

Acknowledgment

The authors are thankful to University of Malaya and Fun-damental Research Grant Scheme (FRGS)-FP 054-2010Bfor providing the necessary facilities and funding for thisresearch

References

[1] W-R Li X-B Xie Q-S Shi S-S Duan Y-S Ouyang andY-B Chen ldquoAntibacterial effect of silver nanoparticles onStaphylococcus aureusrdquo BioMetals vol 24 no 1 pp 135ndash1412011

[2] W-R Li X-B Xie Q-S Shi H-Y Zeng Y-S Ou-Yang andY-B Chen ldquoAntibacterial activity and mechanism of silver

nanoparticles on Escherichia colirdquo Applied Microbiology andBiotechnology vol 85 no 4 pp 1115ndash1122 2010

[3] S S Birla V V Tiwari A K Gade A P Ingle A P Yadavand M K Rai ldquoFabrication of silver nanoparticles by Phomaglomerata and its combined effect against Escherichia coliPseudomonas aeruginosa and Staphylococcus aureusrdquo Letters inApplied Microbiology vol 48 no 2 pp 173ndash179 2009

[4] P Pallavicini A Taglietti G Dacarro et al ldquoSelf-assembledmonolayers of silver nanoparticles firmly grafted on glasssurfaces Low Ag+ release for an efficient antibacterial activityrdquoJournal of Colloid and Interface Science vol 350 no 1 pp 110ndash116 2010

[5] H Oveisi S Rahighi X Jiang et al ldquoUnusual antibacterial pro-perty of mesoporous titania films drastic improvement by con-trolling surface area and crystallinityrdquo Chemistry vol 5 no 9pp 1978ndash1983 2010

[6] CMarambio-Jones and EM VHoek ldquoA review of the antibac-terial effects of silver nanomaterials and potential implicationsfor human health and the environmentrdquo Journal of NanoparticleResearch vol 12 no 5 pp 1531ndash1551 2010

[7] M Gladitz S Reinentnn and H-J Radusch ldquoPreparation ofsilver nanoparticle dispersions via a dendritic-polymer tem-plate approach and their use for antibacterial surface treatmentrdquoMacromolecular Materials and Engineering vol 294 no 3 pp178ndash189 2009

[8] L Ploux M Mateescu K Anselme and K Vasilev ldquoAntibac-terial properties of silver-loaded plasma polymer coatingsrdquoJournal of Nanomaterials vol 2012 Article ID 674145 9 pages2012

[9] W Li ldquoAntibacterial coating incorporating silver nanoparticlesby microarc oxidation and ion implantationrdquo Journal of Nano-materials vol 2013 Article ID 542878 8 pages 2013

[10] W A Ismail Z A Ali and R Puteh ldquoOptical and physicalproperties of methyltrimethoxysilane transparent film incor-porated with nanoparticlesrdquo Advances in Materials Science andEngineering vol 2012 Article ID 124820 6 pages 2012

[11] S Suzuki S Imai and H Kourai ldquoBackground and evidenceleading to the establishment of the JIS standard for antimi-crobial productsrdquo Biocontrol Science vol 11 no 3 pp 135ndash1452006

[12] S ImaiTheDevelopment of an ISO Standard for Measureing theAntibacterial Activity of Surfaces Hygienic Coatings and Sur-faces Paris France 2005

[13] ISO 22196 QualityLabs Np nd Web May 2013[14] J-K Liu X-H Yang and X-G Tian ldquoPreparation of silver

hydroxyapatite nanocomposite spheresrdquo Powder Technologyvol 184 no 1 pp 21ndash24 2008

[15] Q Li S Mahendra D Y Lyon et al ldquoAntimicrobial nanoma-terials for water disinfection and microbial control potentialapplications and implicationsrdquo Water Research vol 42 no 18pp 4591ndash4602 2008

[16] S-H Kim H-S Lee D-S Ryu S-J Choi and D-S Lee ldquoAnti-bacterial activity of silver-nanoparticles against Staphylococcusaureus and Escherichia colirdquoKorean Journal of Microbiology andBiotechnology vol 39 no 1 pp 77ndash85 2011

[17] K B Holt and A J Bard ldquoInteraction of silver(I) ions withthe respiratory chain of Escherichia coli an electrochemical andscanning electrochemical microscopy study of the antimicro-bial mechanism of micromolar Agrdquo Biochemistry vol 44 no39 pp 13214ndash13223 2005


[18] K Kalishwaralal S BarathManiKanth S R K Pandian V Dee-pak and S Gurunathan ldquoSilver nanoparticles impede the bio-film formation by Pseudomonas aeruginosa and StaphylococcusepidermidisrdquoColloids and Surfaces B vol 79 no 2 pp 340ndash3442010

[19] J Y Kim C Lee M Cho and J Yoon ldquoEnhanced inactivationof E coli and MS-2 phage by silver ions combined with UV-Aand visible light irradiationrdquoWater Research vol 42 no 1-2 pp356ndash362 2008

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


For antibacterial activity measurement it is a commonprocedure to carry out the test according to Japanese Indus-trial Standard JIS Z 2801 This method was developed tomeasure the antibacterial activity in hydrophobic materialsoriginally resulting from the incorporation of silver ions intorigid polymers Developed by a consortium of workers com-prised of manufacturers of silver-based antimicrobial agentsgovernment-based research organisations and universitiesunder the organisation of the Society of Industrial technologyfor Antimicrobial Articles (SIAA) the method has then beenvalidated by ring tests within Japan [11] and now forms thebasis of a draft ISO standard which is being validated by theSIAA in collaborationwith the International BiodeteriorationResearch Group (IBRG [12]) In JIS Z 2801 the antibacterialactivity is measured by quantifying the survival of bacterialcells which have been held in intimate contact for 24 hours at35∘C with a surface that contains an antibacterial agent Theantibacterial property is measured by comparing the survivalof bacteria on a treated material with that achieved on anuntreated material

2 Experimental Method

21 Nanosilver Crystal Precipitation Silver nanocrystals wereprepared according to the method reported in [13] 20mL ofethylene diamine was added into the silver nitrate solutionand stirred for 5minutes Cetyltrimethylammoniumbromide(CTAB) was added to the solution as a dispersing agent andstirred vigorously for another 5minutes before adding hydra-zine hydrate The solution was stirred and kept at the roomtemperature for 15minutesTheparticleswere separated fromthe solution by centrifuging the solution at 5000 rpm for 20minutesThe particles were washed from the reactants chem-icals by repeating the centrifuging process with deionisedwater and lastly with ethanol The particles gathered weredried in desiccators for 24 hrs Ball milling process withweight ratio of ball to sample 120 1 was carried out for 4hours at 300 rpm The milled particles were characterisedusing XRD to confirm the crystal structure and estimate thecrystallite size

22 Preparation of Coating Mixture for Antibacterial Test-ing N-propanol and methyltrimethoxy silane (SindashCH

3ndash

(OCH3)3) wasmixed in a beaker with the ratio of 1 1 25wt

of silver nanocrystal was added into the system and wasgrinded in the ball mill for 1 hr Nitric acid was diluted toobtain the pH of 01 and was used as catalyst (10wt) Thecoating process was carried out in room temperature of26∘C and absolute humidity 30 These two factors werekept constant throughout the experiment The dried sampleswere measured for transparency using haze meter with D65illumination light at room temperature and surface qualitywas evaluated using a microscope with 500x maximummagnification

23 Antibacterial Activity Test The dried sample was testedagainst Staphylococcus aureus Escherichia coli and Pseudo-monasAeruginosa according to JIS Z 2801200 (Antimicrobial

20 30

[111][200] [220] [311]

40 50 60 70 80 90 100

XRD peaks for all the samples

06M05M04M03M02M01M

Figure 1 XRD pattern of silver particles produced with varioussilver nitrate molarity

product test for antimicrobial activity and efficacy) by anaccredited testing lab (SIRIM QAS International Sdn Bhd)This ensures and guarantees reliability accuracy and validityof the results

As reported by [11ndash13] the testmicroorganism is preparedby growth in a liquid culture medium The suspension oftest microorganism is standardized by dilution in a nutritivebroth (this affords microorganisms the potential to growduring the test) Control and test surfaces are inoculated with04mL of the germ suspension in triplicate Then the inocu-lum is covered with a film to prevent the evaporation of thesuspension and to ensure close contact with the samples sur-face Immediately after inoculation the bacteria from the ref-erence sample are separated from the sample surfaces and thenumber of viable germs is determined (119905

0value) by elution

followed by dilution and plating The other samples (11990524) are

allowed to incubate in a humid environment for 24 hoursAfter incubation microbial concentrations are determinedby elution followed by dilution and plating Activityefficacyis calculated by comparing the germ concentration after 24hours relative to concentration of the blank sample after 24hours

3 Result and Discussion

31 Structural Study and Determination of Crystallite SizeThe chemical route for the formation of silver nanoparticlescan be described as follows [14]

Ag+ + (CH2NH2)2

997888rarr [Ag(CH2NH2)2

]+ (1)

4[Ag(CH2NH2)2

]+

+ 5N2H4

997888rarr 4Ag + 4N2H5+ N2+ 4 (CH

2NH2)

(2)

In (1) the first reaction of Ag+ with the ethylenediamine isto form the [Ag (CH

2NH2)2]+ complex and the following

reaction in (2) with the hydrazine hydrate to form silvermetal CTAB was added to disperse the particles formedThesilver precipitate produced was structurally analysed by XRDfrom 5∘ to 90∘ 2120579 angle (Figure 1)The same peaks appeared inall of the samples and after fitting and it is confirmed that thecrystal consists of silver atoms only There was no evidenceof oxygen or other atoms existed in the crystal structure Thecrystals formed are face-centered cubic structure







20 times 102

46


95 times 106 mdash


lt10 72


17 times 108 mdash


89 times 102

42


15 times 107 mdash

lowast







36 times 107 mdash


95 times 106 mdash


11 times 108 mdash


17 times 108 mdash


15 times 107 mdash


15 times 107 mdash


398361

188 186 188

380

05

101520253035404550

Crys

talli

te si

ze (n

m)

Molarity (M)060504030201










(a) (b)


(a) (b)

(c)









4 Conclusion


Acknowledgment


References





























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials









20 times 102

46


95 times 106 mdash


lt10 72


17 times 108 mdash


89 times 102

42


15 times 107 mdash

lowast







36 times 107 mdash


95 times 106 mdash


11 times 108 mdash


17 times 108 mdash


15 times 107 mdash


15 times 107 mdash


398361

188 186 188

380

05

101520253035404550

Crys

talli

te si

ze (n

m)

Molarity (M)060504030201










(a) (b)


(a) (b)

(c)









4 Conclusion


Acknowledgment


References





























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(a) (b)


(a) (b)

(c)









4 Conclusion


Acknowledgment


References





























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







4 Conclusion


Acknowledgment


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 transparent nanocrystallite silver...

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