Carbohydrate Polymers 78 (2009) 564–569

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Carbohydrate Polymers

journal homepage: www.elsevier .com/locate /carbpol

The influence of silver content on antimicrobial activity and color of cottonfabrics functionalized with Ag nanoparticles

Vesna Ilic a, Zoran Šaponjic b, Vesna Vodnik b, Branislav Potkonjak c, Petar Jovancic a, Jovan Nedeljkovic b,Maja Radetic a,*

a Textile Engineering Department, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbiab Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbiac Institute of Chemistry, Technology and Metallurgy, Njegoševa 12, 11000 Belgrade, Serbia

a r t i c l e i n f o a b s t r a c t

Article history:Received 18 May 2009Accepted 21 May 2009Available online 31 May 2009

Keywords:Silver nanoparticlesCottonAntibacterial efficiencyDirect dye

0144-8617/$ - see front matter � 2009 Elsevier Ltd. Adoi:10.1016/j.carbpol.2009.05.015

* Corresponding author. Tel.: +381 11 3303 857; faE-mail address: maja@tmf.bg.ac.rs (M. Radetic).

The aim of this study was to examine the antimicrobial efficiency and color changes of cotton fabricsloaded with colloidal silver nanoparticles which were synthesized without using any stabilizer. The influ-ence of colloidal concentration and consequently, the amount of silver deposited onto the fabric surface,on antimicrobial activity against Gram-negative bacterium Escherichia coli, Gram-positive bacteriumStaphylococcus aureus and fungus Candida albicans as well as laundering durability of obtained effectswere studied. Although cotton fabrics loaded with silver nanoparticles from 10 ppm colloid exhibitedgood antimicrobial efficiency, their poor laundering durability indicated that higher concentrated colloids(50 ppm) must be applied for obtaining long-term durability. Additionally, the influence of dyeing withC.I. Direct Red 81 on antimicrobial activity of cotton fabrics loaded with silver nanoparticles as well as theinfluence of their presence on the color change of dyed fabrics were evaluated. Unlike color change, theantimicrobial efficiency was not affected by the order of dyeing and loading of silver nanoparticles.

� 2009 Elsevier Ltd. All rights reserved.

1. Introduction

The interest for efficient, non-toxic, durable and cost-effectiveantimicrobial finishing of textile materials rapidly increases withprogressive production growth of medical, healthcare, hygieneand protective textile materials (Czajka, 2005; Gao & Cranston,2008; Wong, Yuen, Leung, Ku, & Lam, 2006). The minimization ofmicrobial growth on the textile materials is of great importancesince the microbes can harm not only the material itself, but theycan also affect the comfort of wearer. In other words, they maycause plenty of negative effects such as generation of unpleasantodor, stains, decolorisation of the material and a decrease in fabricmechanical strength (Gao & Cranston, 2008; Gorenšek & Recelj,2007). Cotton fibers are particularly suitable for manufacturing ofthe textiles for sports, leisure, medical non-implantable (differentbandages, plasters, gauze dressings, lint, wadding, adsorbent pads)and healthcare/hygiene products (surgical gowns and hosieries,sheets, pillowcases, uniforms, blankets) (Czajka, 2005). However,the ability of cotton to absorb a huge amount of moisture makesthis fiber more prone to microbial attack. Under certain conditionsof humidity and temperature, cotton may act as a nutrient,becoming the suitable medium for bacterial and fungal growth(Gao & Cranston, 2008; Gorenšek & Recelj, 2007).

ll rights reserved.

x: +381 11 3370 857.

A rising problem with microbes resistant to multiple antibioticsrenewed the interest for silver and silver compounds which arehistorically recognized as powerful biocides for more than 650 var-ious microbes. Silver nitrate is commonly used as an antimicrobialagent (Feng et al., 2000; Kostic et al., 2009). Despite the excellentantimicrobial activity, silver nitrate is not appropriate for theapplication to textile materials as it stains to black–brown whenexposed to air and light, due to uncontrolled reduction processes(Vigneshwaran, Kumar, Kathe, Vradarajan, & Prasad, 2006). How-ever, a desirable level of antimicrobial activity without significantcolor change can be obtained with silver nanoparticles (Ag NPs)deposited on the textile materials. Recently developed simpleroutes for synthesis of silver colloids provide good control of nano-particle size. Unlike the bactericide effects of ionic silver, the anti-microbial activity of colloidal Ag NPs is highly influenced by thedimensions of the particles – the smaller the particles, the higherthe antimicrobial efficiency (Panácek et al., 2006). The applicationof Ag NPs in the antimicrobial finishing of textile materials isadvantageous due to their stability and high surface to volumeratio.

Lately, the application of Ag NPs to cotton fabrics received agreat deal of attention particularly because of their high resistanceto microbes. Vigneshwaran et al. developed in situ synthesis ofAg NPs on cotton fabrics where the aldehyde terminal of starch re-duces the silver nitrate to silver metal, simultaneously stabilizingthe NPs on the fabric (Vigneshwaran et al., 2006). Perelshtein

Fig. 1. Dyeing procedure for cotton fabrics.

V. Ilic et al. / Carbohydrate Polymers 78 (2009) 564–569 565

et al. proposed sonochemical coating of Ag NPs using the ultra-sound irradiation (Perelshtein et al., 2008). Durán et al. reportedthat good antibacterial properties can be obtained using the AgNPs produced by fungal process on cotton fabrics (Durán, Marcato,De Souza, Alves, & Esposito, 2007). However, the most of theresearch on the modification of cotton fabrics with Ag NPs so farwas based on the application of commercial Ag NPs or Ag NPs syn-thesized by using the stabilizers (Gorenšek & Recelj, 2007; Lee &Jeong, 2005; Lee, Yeo, & Jeong, 2003; Pohle, Damm, Neuhof, Rösch,& Münstedt, 2007).

Our approach relies on the loading of cotton fabrics with AgNPs, which were obtained from the stable colloids synthesizedwithout using any stabilizer (Radetic et al., 2008; Vukovic & Ned-eljkovic, 1993; Šaponjic, Csencsits, Rajh, & Dimitrijevic, 2003).The absence of stabilizer molecules on the particle surface im-proves the efficiency of the interaction with microbes. This studydiscusses the influence of colloid concentration on antimicrobialactivity and laundering durability of obtained effects, which weretested against Gram-negative bacterium Escherichia coli, Gram-po-sitive bacterium Staphylococcus aureus and fungus Candida albicans.In order to evaluate the synergism between dyeing and loading ofAg NPs, the influence of dyeing with dye C.I. Direct Red 81 on anti-microbial activity of cotton fabrics loaded with Ag NPs as well asthe influence of the presence of Ag NPs on the color change of dyedfabrics were studied.

2. Experimental

2.1. Materials

Desized and bleached cotton fabrics (Co, 168 g/m2) werecleaned as described in our previous study (Radetic et al., 2008).Dye C.I. Direct Red 81 (DR81) was used for dyeing of cotton fabrics.

2.2. Loading of fabrics with Ag NPs

AgNO3 (Kemika) and reducing agent NaBH4 (Fluka) of p.a. gradewere used for the synthesis of colloidal Ag NPs (Radetic et al., 2008;Vukovic & Nedeljkovic, 1993; Šaponjic et al., 2003). 1.7 mg ofAgNO3 was dissolved in 100 mL of water purged by argon for30 min. Under vigorous stirring, 10 mg of NaBH4 was added tothe solution and left for 1 h in argon atmosphere. The concentra-tion of silver colloid was 10 ppm. The silver colloids of higher con-centration (50 ppm) were synthesized in the same manner.

One gram of cotton fabric was immersed in 45 mL of colloid ofAg NPs for 5 min and dried at room temperature. After 5 min ofcuring at 100 �C, the samples were rinsed twice (5 min) withdeionised water and dried at room temperature.

2.3. Dyeing of fabrics

Schematic procedure of dyeing of cotton fabrics is shown inFig. 1. Cotton fabrics were dyed in Polycolor (Werner Mathis AG)laboratory beaker dyer in the bath containing 0.5% (o.w.f.) DR81and 5% (o.w.f.) Na2SO4 at liquor-to-fabric ratio of 100:1. Subse-quently, the fabrics were rinsed with water and dried at roomtemperature.

2.4. Methods

Fiber morphology was followed by scanning electron micro-scope (SEM) JEOL JSM 6460 LV. Gold layer was deposited on thesamples before the analysis.

The content of silver in washing bath after each washing cycleand in the fabrics after the fifth washing cycle was determined

by a Perkin–Elmer 403 atomic absorption spectrometer (AAS). Be-fore the AAS measurements of silver amount in the fabrics, thesamples were burned and dissolved in nitric acid.

The antimicrobial efficiency of cotton fabrics was quantitativelyassessed using a Gram-negative bacterium E. coli ATCC 25922,Gram-positive bacterium S. aureus ATCC 25923 and fungus C. albi-cans ATCC 24433. Bacterial/fungal inoculum was prepared in thetryptone soy broth (Torlak, Serbia), which was used as a growingmedium for microbes, and potassium hydrogen phosphate buffersolution (pH 7.2) as a testing medium. Microbes were cultivatedin 3 mL of tryptone soy broth at 37 �C and left overnight (late expo-nential stage of growth). Sterile potassium hydrogen phosphatebuffer solution (70 mL) was added to sterile Erlenmeyer flask(300 mL), which was then inoculated with 0.7 mL of a bacterial/fungal inoculum. One gram of sterile fabric cut into small pieceswas placed in the flask and shaked for 1 h.

Time zero counts were made by removing 1 mL aliquots fromthe inoculum which were diluted with physiological saline solu-tion. 0.1 mL of the solution was placed onto a tryptone soy agar(Torlak, Serbia) and after 24 h of incubation at 37 �C, the zero timecounts (initial number of microbial colonies) of viable microbeswere made. One hour counts were made in accordance with previ-ously described procedure.

The percentage of microbe reduction (R, %) was calculated usingthe following equation:

R ¼ C0 � CC0

� 100 ð1Þ

where C0 (CFU – colony forming units) is the number of microbialcolonies on the control fabric (untreated fabric without Ag) and C(CFU) is the number of microbial colonies on the fabric loaded withAg NPs (Jeong, Hwang, & Yi, 2005; Ki, Kim, & Kwon, 2007; Lee et al.,2003).

Laundering durability of antimicrobial effect was evaluatedafter five washing cycles in Polycolor (Werner Mathis AG) labora-tory beaker dyer at 45 rpm. The fabrics were washed in the bathcontaining 0.5% Felosan RG-N (Bezema) at liquor-to-fabric ratioof 40:1. After 30 min of washing at 95 �C, the fabrics were rinsedonce with warm water (95 �C) for 3 min and three times (3 min)with cold water. Afterwards, the fabrics were dried at 70 �C (Leeet al., 2003). The percentage of microbe reduction after five wash-ing cycles was determined in accordance with Eq. (1).

Color coordinates of the dyed fabrics (CIE L*, a*, b*) were deter-mined with Datacolor SF300 spectrophotometer under illuminantD65 using the 10� standard observer. On the basis of measuredCIE color coordinates, color difference (DE*) was determined as

DE� ¼ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiðDa�Þ2 þ ðDb�Þ2 þ ðDL�Þ2

qð2Þ

where DL* – is the color lightness difference between treated (dyedfabric loaded with Ag NPs) and control (dyed fabric without Ag)samples; Da* – red/green difference between treated and control

566 V. Ilic et al. / Carbohydrate Polymers 78 (2009) 564–569

samples; Db* – yellow/blue difference between treated and controlsamples.

3. Results and discussion

In this study, nearly spherical uniform Ag NPs with a meandiameter of approximately 10 nm were synthesized without usingany stabilizer as explained in our previous work (Radetic et al.,2008).

The morphological changes of cotton fibers caused by deposi-tion of Ag NPs were followed by SEM. SEM images of cotton fibersloaded with Ag NPs from 10 ppm and 50 ppm colloids are pre-sented in Fig. 2. The presence of characteristic folds running paral-lel to the elongation direction of the pristine cotton fiber is evidentin both images (Uddin et al., 2007). The presence of Ag NPs cannotbe observed on cotton fiber loaded with Ag NPs from 10 ppm col-loid likely due to low concentration of precursor solution (Fig. 2a).On the contrary, the cotton fiber loaded with Ag NPs from 50 ppmcolloid is covered with well dispersed quite uniform Ag NPs(Fig. 2b). Few aggregates consisting of smaller particles are alsonoticeable.

The presence of Ag NPs was additionally confirmed by UV/VISreflectance spectra measurements (Fig. 3). The obtained homoge-neous color change of fabrics from white to yellow after Ag NPsdeposition is in accordance with literature data (Radetic et al.,2008; Yuranova et al., 2003). The color was maintained even afterrinsing in water and drying, confirming the binding of the nanopar-

Fig. 2. SEM images of cotton loaded with Ag NPs from (a) 10 ppm colloid and (b)50 ppm colloid.

ticles on the surface of the cotton fibers (Falletta et al., 2008). Fig. 3reveals slight decrease in reflectance intensity of cotton fabricloaded with Ag NPs from 10 ppm colloid compared to that of controlcotton fabric. The shape of reflectance curve is also preserved. Thecolor change was considerably more prominent on the fabric loadedwith Ag NPs from 50 ppm colloid. This is in a good correlation withSEM observations. In addition to considerable change of the reflec-tance intensity which shows overall decrease, the shape of the reflec-tance curve differs particularly in the high energy region indicatingthe appearance of plasmon resonance band of Ag NPs. Observedred shift of plasmon resonance band compared to its position ofnon-agglomerated Ag NPs in initial aqueous colloid (380 nm) isattributed to higher dielectric constant of the surrounding mediuminduced by the inter-particle coupling of Ag NPs agglomerated onthe fiber surface (Šaponjic et al., 2003). The color changes of cottonfabrics after deposition of Ag NPs were quantitatively determinedusing the CIE L*a*b* coordinates (Table 1). While the deposition ofAg NPs from 10 ppm colloid caused only slight color change, whichcannot be visually detected (DE* < 1), the color deference tends tobe considerable after loading of Ag NPs from 50 ppm colloid(DE* = 15.09).

Antimicrobial efficiency of cotton fabrics was tested againstGram-negative bacterium E. coli, Gram-positive bacterium S. aureusand fungus C. albicans. The values of microbial reduction of cottonfabrics loaded with Ag NPs are given in Table 2. Cotton fabrics loadedwith Ag NPs from 10 ppm colloid exhibited good antimicrobial effi-ciency, but maximum microbial reduction was reached only againstS. aureus. The loading of Ag NPs from higher concentrated colloid ledto a maximum microbial reduction independently of the microbetype. Achieved maximum antimicrobial activity retained even afterfive washing cycles, indicating excellent laundering durability of ob-tained effects (Table 3). On the contrary, cotton fabrics loaded withAg NPs from 10 ppm colloid exhibited very poor laundering durabil-ity. These results indicated that for durable antimicrobial finishing ofcotton fabrics, higher concentrations of Ag colloid have to be applied.Higher concentrated colloid provides overall increase of silver activesurface owing to high surface to volume ratio of each nanoparticle.Lee et al. also reported that fabrics loaded with Ag NPs from50 ppm colloid exhibited better bacteriostatic properties againstKlebsiella pneumoniae and S. aureus than samples treated with25 ppm colloid (Lee et al., 2003).

The amount of silver released during washing was quantita-tively evaluated by atomic absorption spectroscopy. The amountsof silver released from 1 g of cotton fabric loaded with Ag NPs intothe washing bath after each washing cycle are shown in Fig. 4. The

Fig. 3. Reflectance spectra of control cotton fabric and cotton fabrics loaded withAg NPs.

Table 1Colorimetric data for cotton fabrics loaded with Ag NPs.

Sample L* a* b* DE* Description

Control Co 92.72 �0.18 1.36Co + Ag (10 ppm) 91.90 0.30 1.52 0.963 Darker, less green, yellowCo + Ag (50 ppm) 83.77 2.28 13.26 15.09 Darker, less green, yellow

Table 2Antimicrobial efficiency of Ag loaded cotton fabrics.

Sample Microbe Initial number ofmicrobial colonies(CFU)

Number of microbialcolonies on the fabric(CFU)

R (%)

Control Co E. coli 2.4 � 105 7.7 � 104

Co + Ag (10 ppm) 2.4 � 102 99.7Control Co 1.2 � 106 2.0 � 105

Co + Ag (50 ppm) <10 99.9

Control Co S. aureus 2.2 � 105 8.8 � 104

Co + Ag (10 ppm) 1.0 � 102 99.9Control Co 5.2 � 105 6.7 � 104

Co + Ag (50 ppm) <10 99.9

Control Co C. albicans 2.0 � 105 9.7 � 104

Co + Ag (10 ppm) 1.8 � 102 99.8Control Co 3.0 � 105 2.6 � 105

Co + Ag (50 ppm) <10 99.9

Table 3Antimicrobial efficiency of Ag loaded cotton fabrics after five washing cycles.

Sample Microbe Initial number ofmicrobial colonies(CFU)

Number of microbialcolonies on the fabricafter washing (CFU)

R (%)

Control Co E. coli 2.4 � 105 7.7 � 104

Co + Ag (10 ppm) 7.5 � 104 14.8Control Co 6.2 � 105 5.7 � 104

Co + Ag (50 ppm) <10 99.9

Control Co S. aureus 2.2 � 105 8.8 � 104

Co + Ag (10 ppm) 1.1 � 105 0Control Co 2.0 � 105 7.6 � 104

Co + Ag (50 ppm) <10 99.9

Control Co C. albicans 2.0 � 105 9.7 � 104

Co + Ag (10 ppm) 8.7 � 104 10.3Control Co 2.4 � 105 6.4 � 104

Co + Ag (50 ppm) <10 99.9

Fig. 4. The release of silver from cotton fabrics loaded with Ag NPs during washing.

V. Ilic et al. / Carbohydrate Polymers 78 (2009) 564–569 567

results suggest that silver releases during the washing of cottonfabrics as well as that the amount of silver released in each subse-quent washing cycle decreases. It is noticeable that the release ofsilver from the cotton fabrics treated with 10 ppm colloid was fas-ter and already after the second washing cycle no silver was de-tected in the washing bath. Only 0.4 lg of silver was found in 1 gof cotton fabric after the last washing cycle, indirectly explainingthe poor laundering durability of obtained antimicrobial effects.Additionally, these results indicate low total content of silver inthe samples loaded with Ag NPs from 10 ppm colloid, also clarify-ing the lack of visible Ag NPs on the cotton fiber in Fig. 2a.

The release of silver from the cotton fabric treated with 50 ppmcolloid was considerably slower. After the fifth washing cycle only0.6 lg of silver in the washing bath was found. Silver (4.0 lg) is lefton the sample after the fifth washing cycle. This amount is 10times higher compared to the amount left after washing in the cot-ton fabric loaded with Ag NPs from 10 ppm colloid. Evidently, thehigher amount of retained silver provides desirable launderingdurability. In spite of small amount of silver left, this quantity issufficient to provide required bactericidal and fungicidal activity.

The results pointed out that certain amount of silver retained onthe cotton fabrics after applied washing procedure. The retainedsilver presents nanoparticles that are probably chemically boundto the cotton fibers. Unfortunately, obtained results do not revealin what form silver was released from the cotton fabric into thewashing bath neither in what form it kills microbes. The exactmechanism by which Ag NPs interact with bacteria is not totallyclear yet. One scientific approach relies on the assumption thatAg ions released from Ag NPs are responsible for killing the bacte-ria (Damm, Muenstedt, & Roesch, 2007; Morones et al., 2005;Perelshtein et al., 2008; Pohle et al., 2007; Xu et al., 2006). In con-tact with water and dissolved oxygen, Ag NPs release smallamounts of silver ions according to equation (Hoskins, Karanfil, &Serkiz, 2002):

O2ðaqÞ þ 4H3Oþ þ 4AgðsÞ ! 4AgþðaqÞ þ 6H2O ð3Þ

However, another approach is oriented towards the work ofMorones et al. who reported the presence of small-sized Ag NPs at-tached to the cell membrane and inside the bacteria which are cru-cial findings for understanding the bactericidal mechanism of AgNPs (Morones et al., 2005). Silver exhibits high affinity to reactwith sulfur and phosphorous compounds (Hatchett & Henry,1996). Therefore, it can be expected that Ag NPs react with sulfurreach protein in the bacteria cell membrane and interior of the cellor with phosphorous-containing compounds such as DNA (Fenget al., 2000; Kim, 2007). Consequently, the morphological changesin the cell membrane of bacteria and possible damage of DNA trig-gered by reaction with Ag NPs, negatively affect the respiratorychain or cell division processes, leading to a cell death (Moroneset al., 2005).

From technological point of view it is very important to estab-lish the relationship between dyeing and antimicrobial finishingof textiles. One aspect covers the impact of dyeing on the antimi-crobial activity of cotton fabrics loaded with Ag NPs. Another onecorresponds to the influence of the presence of Ag NPs on the colorchange of dyed cotton fabrics. This examination was performed onthe cotton fabrics loaded with Ag NPs from 50 ppm colloid.

Table 4Antimicrobial efficiency of cotton fabrics loaded with Ag NPS from 50 ppm colloidbefore and after dyeing.

Sample Microbe Initial number ofmicrobial colonies(CFU)

Number ofmicrobial colonieson the fabric (CFU)

R (%)

Control Co E. coli 2.2 � 105 4.6 � 104

Co + Ag + DR81a <10 99.9Co + DR81 + Agb <10 99.9

Control Co S. aureus 2.1 � 105 8.7 � 104

Co + Ag + DR81 <10 99.9Co + DR81 + Ag <10 99.9

Control Co C. albicans 2.0 � 105 3.4 � 104

Co + Ag + DR81 <10 99.9Co + DR81 + Ag <10 99.9

a Loading before dyeing.b Loading after dyeing.

Table 5Colorimetric data for cotton fabrics loaded with Ag NPs from 50 ppm colloid beforeand after dyeing.

Sample L* a* b* DE* Description

Control Co 56.27 47.62 5.65Co + Ag + DR81a 55.73 46.43 5.05 1.443 Darker, less red, less yellowCo + DR81 + Agb 57.99 45.62 6.35 2.733 Lighter, less red, yellow

a Loading before dyeing.b Loading after dyeing.

568 V. Ilic et al. / Carbohydrate Polymers 78 (2009) 564–569

The antimicrobial efficiency of cotton fabrics loaded with AgNPs against Gram-negative bacterium E. coli, Gram-positive bacte-rium S. aureus and fungus C. albicans before and after dyeing is pre-sented in Table 4. These results indicate that dyeing with DR81 didnot affect the antimicrobial activity of Ag NPs. It is evident that AgNPs deposited on the cotton fabrics can provide maximum micro-bial reduction independently of the order of the operations i.e.dyeing and Ag loading.

Taking into the consideration a strong impact of fiber surfacemodification on dyeability of textile materials, the effect of AgNPs deposition onto cotton fabrics before and after dyeing on colorchange of fabrics was examined by measuring reflectance spectra.The color changes were evaluated via CIE L*a*b* color coordinates.Colorimetric data for control fabric and fabrics loaded with AgNPs before and after dyeing with DR81 are presented in Table 5.As expected, the deposition of Ag NPs led to a color change inde-pendently of the order of Ag loading and dyeing, which could bevisually detected since in both cases the color difference (DE*)was higher than one. Ag loading after dyeing brought about almostdoubled color difference compared to the results obtained for theopposite order of operations. Therefore, according to results of col-orimetric measurements, it is suggested that loading of Ag NPsafter dyeing should be avoided because of the considerable colorchange. These color changes are attributed to the presence of AgNPs and they are in good correlation with our previous studies cor-responding to polyamide and polyester fabrics (Ilic et al., 2009).

4. Conclusions

Cotton fabrics loaded with silver nanoparticles from 10 ppmand 50 ppm colloid exhibited excellent antimicrobial activityagainst Gram-negative bacterium E. coli, Gram-positive bacteriumS. aureus and fungus C. albicans. Cotton fabrics loaded with silvernanoparticles from 10 ppm colloid showed poor laundering dura-bility of obtained effects. However, the desirable antimicrobial

efficiency of the cotton fabrics loaded with silver nanoparticlesfrom 50 ppm colloid was preserved after five washing cycles. Thiscould be attributed to higher amount of silver detected in the cot-ton fabrics loaded with silver nanoparticles from 50 ppm colloid.

The order of loading of silver nanoparticles and dyeing with C.I.Direct Red 81 do not affect the antimicrobial efficiency of cottonfabrics loaded with silver nanoparticles from 50 ppm colloid. How-ever, it is suggested to avoid the loading of silver nanoparticlesafter dyeing because of the significant color change of cottonfabrics.

Acknowledgements

This study was supported by the Ministry of Science of the Repub-lic of Serbia – Project TR19007 and Eureka Project E !4043 – NANO-VISION. We gratefully acknowledge M. Bokorov (University of NoviSad, Serbia) for providing SEM measurements.

References

Czajka, R. (2005). Development of medical textiles. Fibers and Textiles in EasternEurope, 13, 13–15.

Damm, C., Muenstedt, H., & Roesch, A. (2007). Long-term antimicrobial polyamide6/silver-nanocomposites. Journal of Material Science, 42, 6067–6073.

Durán, N., Marcato, P., De Souza, G. I. H., Alves, O. L., & Esposito, E. (2007).Antibacterial effect of silver nanoparticles produced by fungal process on textilefabrics and their effluent treatment. Journal of Biomedical Nanotechnology, 3,203–208.

Falletta, E., Bonini, M., Fratini, E., Lo Nostro, A., Pesavento, G., Becheri, A., et al.(2008). Clusters of poly(acrylates) and silver nanoparticles: Structure andapplications for antimicrobial fabrics. Journal of Physical Chemistry C, 112,11758–11766.

Feng, Q. L., Wu, J., Chen, G. Q., Cui, F. Z., Kim, T. N., & Kim, J. O. (2000). A mechanismstudy of antibacterial effect of silver ions on Escherichia coli and Staphylococcusaureus. Journal of Biomedical Material Research, 52, 662–668.

Gao, Y., & Cranston, R. (2008). Recent advances in antimicrobial treatments oftextiles. Textile Research Journal, 78, 60–72.

Gorenšek, M., & Recelj, P. (2007). Nanosilver functionalized cotton fabric. TextileResearch Journal, 77, 138–141.

Hatchett, D. W., & Henry, S. (1996). Electrochemistry of sulfur adlayers on the low-index faces silver. Journal of Physical Chemistry, 100, 9854–9859.

Hoskins, J. S., Karanfil, T., & Serkiz, S. M. (2002). Removal and sequestration of iodideusing silver-impregnated activated carbon. Environmental Science andTechnology, 36, 784–789.

Ilic, V., Šaponjic, Z., Vodnik, V., Mihailovic, D., Jovancic, P., Nedeljkovic, J., et al.(2009). The study of antibacterial efficiency and coloration of dyed polyamideand polyester fabrics modified with colloidal Ag nanoparticles. Journal of theSerbian Chemical Society, 74, 349–357.

Jeong, H. S., Hwang, Y. H., & Yi, S. C. (2005). Antibacterial properties of padded PP/PEnonwovens incorporating nano-sized silver colloids. Journal of Material Science,40, 5413–5418.

Ki, H. Y., Kim, J. H., & Kwon, S. C. (2007). A study on multifunctional wool textilestreated with nano-sized silver. Journal of Material Science, 42, 8020–8024.

Kim, J. S. (2007). Antibacterial activity of Ag+ ion-containing silver nanoparticlesprepared using the alcohol reduction method. Journal of Indian EngineeringChemistry, 13, 718–722.

Kostic, M., Radic, N., Obradovic, B. M., Dimitrijevic, S., Kuraica, M. M., & Škundric, P.(2009). Silver loaded cotton/polyester fabric modified by dielectric barrierdischarge treatment. Plasma Polymers and Processes, 6, 58–67.

Lee, H. J., Yeo, S. Y., & Jeong, S. H. (2003). Antibacterial effect of nanosized silvercolloidal solution on textiles fabrics. Journal of Material Science, 38, 2199–2204.

Lee, H. J., & Jeong, S. H. (2005). Bacteriostasis and skin innoxiousness of nanosizesilver colloids on textile fabrics. Textile Research Journal, 75, 551–556.

Morones, J. R., Elechiguerra, J. L., Camacho, A., Holt, K., Kouri, J. N., Ramirez, J. T., et al.(2005). The antibactericidal effect of silver nanoparticles. Nanotechnology, 16,2346–2353.

Panácek, A., Kvítek, L., Prucek, R., Kolár, M., Vecerová, R., Pizurová, N., et al. (2006).Silver colloid nanoparticles: Synthesis, characterization, and their antibacterialactivity. Journal of Physical Chemistry B, 110, 16248–16253.

Perelshtein, I., Applerot, G., Perkas, N., Guibert, G., Mikhailov, S., & Gedanken, A.(2008). Sonochemical coating of silver nanoparticles on textile fabrics(nylone, polyester and cotton) and their antibacterial activity.Nanotechnology, 19, 1–6.

Pohle, D., Damm, C., Neuhof, J., Rösch, A., & Münstedt, H. (2007). Antimicrobialproperties of orthopaedic textiles after in-situ deposition of silvernanoparticles. Polymers and Polymer Composites, 15, 357–363.

Radetic, M., Ilic, V., Vodnik, V., Dimitrijevic, S., Jovancic, P., Šaponjic, Z., et al. (2008).Antibacterial effect of silver nanoparticles deposited on corona treatedpolyester and polyamide fabrics. Polymers for Advanced Technologies, 19,1816–1821.

V. Ilic et al. / Carbohydrate Polymers 78 (2009) 564–569 569

Šaponjic, Z. V., Csencsits, R., Rajh, T., & Dimitrijevic, N. (2003). Self-assembly of topo-derivatized silver nanoparticles into multilayered film. Chemistry of Materials,15, 4521–4526.

Uddin, M. J., Cesano, F., Bonino, F., Bordiga, S., Spoto, G., Scarano, D., et al.(2007). Photoactive TiO2 films on cellulose fibres: Synthesis andcharacterization. Journal of Photochemistry and Photobiology A, 189,286–294.

Vigneshwaran, N., Kumar, S., Kathe, A. A., Vradarajan, P. V., & Prasad, V. (2006).Functional finishing of cotton fabrics using zinc oxide-soluble starchnanocomposites. Nanotechnology, 17, 5087–5095.

Vukovic, V. V., & Nedeljkovic, J. M. (1993). Surface modification of nanometer-scalesilver particles by imidazole. Langmuir, 9, 980–983.

Wong, Y. W. H., Yuen, C. W. M., Leung, M. Y. S., Ku, S. K. A., & Lam, L. I. (2006). Selectedapplications of nanotechnology in textiles. Autex Research Journal, 6, 1–8.

Xu, X., Yang, Q., Wang, Y., Yu, H., Chen, X., & Jing, X. (2006). Biodegradableelectrospun poly(L-lactide) fibers containing antibacterial silver nanoparticles.European Polymer Journal, 42, 2081–2087.

Yuranova, T., Rincon, A. G., Bozzi, A., Parra, S., Pulgarin, C., Albers, P., et al. (2003).Antibacterial textiles prepared by RF-plasma and vacuum-UV mediateddeposition of silver. Journal of Photochemistry and Photobiology A, 161, 27–34.