**3.2 Triclosan**

Triclosan (2,4,4-hydrophenyl trichloro (II) ether), a member of the antiseptic and disinfectant family. Triclosan is a halogen containing derivative of phenol, and is used in cosmetics and toothpastes. It has a wide range of action against gram-negative and gram positive bacteria. This compound, thanks to the presence of the acaricide benzyl benzoate, also offers protection against mites and is used in acaricide (spray or powder) formulas, as well as in a solution (25% concentration) for the treatment of scabies. This compound is non toxic. Benzyl benzoate is an acaricide that acts, chemically, directly on the mites.

Due to its antibacterial properties, triclosan has found widespread use in a variety of consumer products including toothpastes, deodorants, soaps, polymers and fibers. (Allmyr et al, 2006)

## **3.3 Metallic salts**

Numerous chemicals have been used to improve the antimicrobial activity of cotton textiles. Many heavy metals are toxic to microbes at very low concentrations either in the free state or in compounds. They kill microbes by binding to intracellular proteins and inactivating

Antibacterial Agents in Textile Industry 391

The result of counting test is shown in Figure 1. As it can be seen, no colony of bacteria was found in agar culture for Ag and Cu loaded samples. It means that the bacteria were killed by silver and copper loading of cotton fabric and causes 100 % reduction of bacterial growth. The interaction between silver and copper ions with bacteria can change the metabolic activity of bacteria and eventually causes the death. Also the results related to Nickel and Cobalt loaded samples shown a few amounts of bacteria spread over the agar plate. However, in case of Ti, Sn and Sb loading, it is seen that, more survival bacteria remain and growth in agar culture. The counting test results related to Sb-loaded samples as compared with Sn and Ti, showed better result, and caused fewer bacteria to growth. Although the amount of survival bacteria for Sn-loaded sample as compared with Ti-loaded one are less. In this research work no ultraviolet light were used before bacteria counting test for Tiloaded sample and all the samples were analyzed in same condition without UV light. So the results related to bacterial counting test for Ti loaded sample shows moderate reduction percentage of bacteria however by using proper UV light, more reduction of bacterial

It can be concluded that, silver and copper salts causes killing of bacteria and percentage reduction of bacteria reach to 100%. It means that, no bacteria can spread over the agar plate. Also the results of antibacterial efficiency for Cu, Ni and Co loaded samples are very good. And the antibacterial activity for Sn and Ti is moderate as compared with the mentioned elements, However better antibacterial efficiency were achieved for Sb treated sample as compared with Ti and Sn. Scanning Electron Microscope (SEM) is the best known and most widely used tool for morphological analyses. SEM micrographs of untreated cotton fabric and metal salt loaded samples are shown in Figure 2. As shown, some new particles were created on the surface of treated cotton fabrics that did not exist on the surface of untreated one. As it is seen, the particles size appears on the surface of Sb and Sn loaded samples are larger than the others but it does not mean that large size of these particles made our

Titanium dioxide (TiO2) photocatalysts, as alternative materials to degrade organic substances for applications, have attracted much attention since the discovery of photoinduced water cleavage on TiO2 electrodes by Fujishima and Honda in the early 1970s. When TiO2 is exposed to ultraviolet light (λ<400 nm), holes (hvb+ ) and excited electrons (ecb−) are generated. The hole is capable of oxidizing water or hydroxide anions into hydroxyl radicals (UOH). UOH is known to be powerful, indiscriminate oxidizing agents to degrade a wide range of organic pollutants, including aromatics and aliphatics, dyes, pesticides and herbicides. In 1985, Matsunaga et al. reported the antibacterial properties of TiO2 for the first time, which attributed to the high redox potential of the surface species, affording non-selective oxidation of bacteria. Since then, TiO2, as the photo-induced antibacterial agent, has attracted increasing interest. With high photo-reactivity, cheapness, non-toxicity and chemical stability, TiO2 is promising for eliminating microorganisms in self-cleaning and self-sterilizing materials. Photo-excited charge carriers, i.e. electrons and holes, may recombine within nanoseconds. The antibacterial efficiency is determined by the competition between the recombination of charge carriers and the transfer of those to the bacteria. A wide range of transition metal ions has been reported to be used as electron acceptor to decrease the e−–h+ recombination in the research of photodegradation towards organic substance. Whereas, noble metal, such as Ag, was explored most as antibacterial effect is concerned**. (**Zhang et al, 2008; Robertson et al, 2005; Matsunaga et al, 1985; Liu et al,

samples with more antibacterial efficiency. (Ghoranneviss et al, 2012)

colonies can be maintained.

2008 ; Hashemikia et al, 2012)

them.( Shahidi et al, 2010) Although some other metals, such as copper, zinc and cobalt, have attracted attention as effective antimicrobial agents for textiles, silver is by far the most widely used in general textiles as well as in wound dressings. It has a MIC value of 0.05– 0.1 mg/l against *E. coli*.

Some concerns have been expressed about the development of bacterial resistance to silver.

For synthetic fibers, silver particles can be incorporated into the polymer before extrusion or before nanofiber formation using electro spinning.

The treatment of natural fibers with metals can only be undertaken at the finishing stage and various strategies have been devised to enhance the uptake and durability. Cotton has been pretreated with succinic acid anhydride, which acted as ligand for metal ions to enhance the subsequent adsorption of metallic salts (Ag+ and Cu2+) and to provide very effective antibacterial activity.

Preparation of nano-sized metals and metal oxides, mainly silver (Ag), titanium dioxide (TiO2), zinc oxide (ZnO) and cooper II oxide (CuO) has enabled the development of a new generation of biocides.

Among these antimicrobial agents, silver has been widely used in many fields because it shows strong biocidal effects on many pathogenic bacteria. In addition, nanosized inorganic particles possess high surface area/volume ratio and display unique physical and chemical properties. Accordingly, the immobilization of silver nanoparticles on various fibers has recently attracted a great deal of attention. Concerning the studies of fiber/silver nanocomposites, most researches have been interest in preparations of ultrafine fiber containing silver nanoparticles. These developments are important and contribute greatly to the textile industry. However, the conventional cotton microfibers are still highly popular in textile markets. Surface modification of cotton microfibers with silver nanoparticles can increase both the price and purpose of the fibers. (Chen & Li Chiang, 2008)

The antimicrobial properties of the silver ion Ag+ have been exploited for a long time in the biomedical field. The significant feature of the silver ion is its broad-spectrum antimicrobial property, which is particularly significant for the polymicrobial colonization associated with biomaterial related infections. The general finding is that bacteria show a low propensity to develop resistance to silver-based products, and therefore both metallic and ionic silver have been incorporated into several biomaterials such as polyurethane, hydroxyapatite (HA) and bioactive glasses.

Silver containing products are also interesting materials for wound repair applications. When metallic silver reacts with moisture on the skin surface or with wound fluids, silver ions are released, damaging bacterial RNA and DNA, thus inhibiting replication. Sustained silver release products have a bactericidal action and manage wound exudates and odour. In particular, Lansdown et al. have shown that silver aids healing in the sterile skin wound in rat models: silver treatment appeared to reduce the inflammatory and granulation tissue phases of healing and induce epidermal repair. **(**Blaker et al, 2004; Potiyaraj et al, 2007; Bingshe et al, 2007; Chen & Schluesener et al, 2008; Montazer et al, 2012; Ibrahim et al, 2012)

The results of the counting test showed more reduction of survival of bacteria in the case of loading samples with metal salts.

them.( Shahidi et al, 2010) Although some other metals, such as copper, zinc and cobalt, have attracted attention as effective antimicrobial agents for textiles, silver is by far the most widely used in general textiles as well as in wound dressings. It has a MIC value of 0.05– 0.1

Some concerns have been expressed about the development of bacterial resistance to silver. For synthetic fibers, silver particles can be incorporated into the polymer before extrusion or

The treatment of natural fibers with metals can only be undertaken at the finishing stage and various strategies have been devised to enhance the uptake and durability. Cotton has been pretreated with succinic acid anhydride, which acted as ligand for metal ions to enhance the subsequent adsorption of metallic salts (Ag+ and Cu2+) and to provide very

Preparation of nano-sized metals and metal oxides, mainly silver (Ag), titanium dioxide (TiO2), zinc oxide (ZnO) and cooper II oxide (CuO) has enabled the development of a new

Among these antimicrobial agents, silver has been widely used in many fields because it shows strong biocidal effects on many pathogenic bacteria. In addition, nanosized inorganic particles possess high surface area/volume ratio and display unique physical and chemical properties. Accordingly, the immobilization of silver nanoparticles on various fibers has recently attracted a great deal of attention. Concerning the studies of fiber/silver nanocomposites, most researches have been interest in preparations of ultrafine fiber containing silver nanoparticles. These developments are important and contribute greatly to the textile industry. However, the conventional cotton microfibers are still highly popular in textile markets. Surface modification of cotton microfibers with silver nanoparticles can

The antimicrobial properties of the silver ion Ag+ have been exploited for a long time in the biomedical field. The significant feature of the silver ion is its broad-spectrum antimicrobial property, which is particularly significant for the polymicrobial colonization associated with biomaterial related infections. The general finding is that bacteria show a low propensity to develop resistance to silver-based products, and therefore both metallic and ionic silver have been incorporated into several biomaterials such as polyurethane, hydroxyapatite

Silver containing products are also interesting materials for wound repair applications. When metallic silver reacts with moisture on the skin surface or with wound fluids, silver ions are released, damaging bacterial RNA and DNA, thus inhibiting replication. Sustained silver release products have a bactericidal action and manage wound exudates and odour. In particular, Lansdown et al. have shown that silver aids healing in the sterile skin wound in rat models: silver treatment appeared to reduce the inflammatory and granulation tissue phases of healing and induce epidermal repair. **(**Blaker et al, 2004; Potiyaraj et al, 2007; Bingshe et al, 2007; Chen & Schluesener et al, 2008; Montazer et al, 2012; Ibrahim et al, 2012) The results of the counting test showed more reduction of survival of bacteria in the case of

increase both the price and purpose of the fibers. (Chen & Li Chiang, 2008)

mg/l against *E. coli*.

effective antibacterial activity.

generation of biocides.

(HA) and bioactive glasses.

loading samples with metal salts.

before nanofiber formation using electro spinning.

The result of counting test is shown in Figure 1. As it can be seen, no colony of bacteria was found in agar culture for Ag and Cu loaded samples. It means that the bacteria were killed by silver and copper loading of cotton fabric and causes 100 % reduction of bacterial growth. The interaction between silver and copper ions with bacteria can change the metabolic activity of bacteria and eventually causes the death. Also the results related to Nickel and Cobalt loaded samples shown a few amounts of bacteria spread over the agar plate. However, in case of Ti, Sn and Sb loading, it is seen that, more survival bacteria remain and growth in agar culture. The counting test results related to Sb-loaded samples as compared with Sn and Ti, showed better result, and caused fewer bacteria to growth. Although the amount of survival bacteria for Sn-loaded sample as compared with Ti-loaded one are less. In this research work no ultraviolet light were used before bacteria counting test for Tiloaded sample and all the samples were analyzed in same condition without UV light. So the results related to bacterial counting test for Ti loaded sample shows moderate reduction percentage of bacteria however by using proper UV light, more reduction of bacterial colonies can be maintained.

It can be concluded that, silver and copper salts causes killing of bacteria and percentage reduction of bacteria reach to 100%. It means that, no bacteria can spread over the agar plate. Also the results of antibacterial efficiency for Cu, Ni and Co loaded samples are very good. And the antibacterial activity for Sn and Ti is moderate as compared with the mentioned elements, However better antibacterial efficiency were achieved for Sb treated sample as compared with Ti and Sn. Scanning Electron Microscope (SEM) is the best known and most widely used tool for morphological analyses. SEM micrographs of untreated cotton fabric and metal salt loaded samples are shown in Figure 2. As shown, some new particles were created on the surface of treated cotton fabrics that did not exist on the surface of untreated one. As it is seen, the particles size appears on the surface of Sb and Sn loaded samples are larger than the others but it does not mean that large size of these particles made our samples with more antibacterial efficiency. (Ghoranneviss et al, 2012)

Titanium dioxide (TiO2) photocatalysts, as alternative materials to degrade organic substances for applications, have attracted much attention since the discovery of photoinduced water cleavage on TiO2 electrodes by Fujishima and Honda in the early 1970s. When TiO2 is exposed to ultraviolet light (λ<400 nm), holes (hvb+ ) and excited electrons (ecb−) are generated. The hole is capable of oxidizing water or hydroxide anions into hydroxyl radicals (UOH). UOH is known to be powerful, indiscriminate oxidizing agents to degrade a wide range of organic pollutants, including aromatics and aliphatics, dyes, pesticides and herbicides. In 1985, Matsunaga et al. reported the antibacterial properties of TiO2 for the first time, which attributed to the high redox potential of the surface species, affording non-selective oxidation of bacteria. Since then, TiO2, as the photo-induced antibacterial agent, has attracted increasing interest. With high photo-reactivity, cheapness, non-toxicity and chemical stability, TiO2 is promising for eliminating microorganisms in self-cleaning and self-sterilizing materials. Photo-excited charge carriers, i.e. electrons and holes, may recombine within nanoseconds. The antibacterial efficiency is determined by the competition between the recombination of charge carriers and the transfer of those to the bacteria. A wide range of transition metal ions has been reported to be used as electron acceptor to decrease the e−–h+ recombination in the research of photodegradation towards organic substance. Whereas, noble metal, such as Ag, was explored most as antibacterial effect is concerned**. (**Zhang et al, 2008; Robertson et al, 2005; Matsunaga et al, 1985; Liu et al, 2008 ; Hashemikia et al, 2012)

Antibacterial Agents in Textile Industry 393

Fig. 2. The SEM images of metallic loaded cotton

Fig. 1. The bacterial counting test for comparing the antibacterial activity of metallic loaded cotton

Fig. 1. The bacterial counting test for comparing the antibacterial activity of metallic loaded

cotton

Fig. 2. The SEM images of metallic loaded cotton

Antibacterial Agents in Textile Industry 395

applications of the sputter coated materials.( Scholz et al, 2005; Wei et al, 2008; Hegemann et

The advantages of sputtering are the following: simple process, time saving, environmental

Deposition of copper on the surface of cotton samples was performed in DC magnetron sputtering, made by Plasma Physics Research Center (Tehran, Iran), by using the setup schematically presented in Figure 3. Copper post cathode was used; also as it can be seen that samples were placed on the anode, and exposed to argon plasma in a cylindrical glass tube. The chamber was evacuated to a pressure of 10-5 Torr, using rotary and diffusion pumps, and then argon gas was introduced into the chamber up to a pressure of 0.05 Torr.

Copper particles were deposited on the surface of cotton samples, and the antibacterial has been developed, through incorporation of copper particles on fabric surfaces. The antibacterial properties of the fabrics were connected with the presence of copper on their surface. After plasma treatment, the physical and chemical properties of the fabrics have been examined by surface analysis methods and textile technology tests. Also the

The agar culture medium is transparent, when the bacterium is inhibited from growth, a

There is no halo observed for untreated cotton fabric. This control test shows that the original cotton fabric does not have any antibacterial properties. Figure 4 illustrate the test results for the untreated and cotton-coated fabric for 30 seconds with S. aureus. (Shahidi et

al, 2007; Yuranova et al, 2003 ; Brunon et al, 2011 ; Yuranova et al, 2003)

friendly, and a resulting coating with superior adhesion to substrates.

Voltage was kept at 950 V and the discharge current was about 220 mA.

Fig. 3. The schematic view of Plasma sputtering system

antibacterial efficiency was determined by the Halo method.

al, 2007; Ghoranneviss et al, 2011)

transparent area in the form of a halo around the fabric will be observed.

The ZnO nanoparticles have been measured to possess probable biological applications as efficient antimicrobial agents, drug carriers, bioimaging probes and possessing cytotoxic behavior for the treatment of cancer. Being a semiconducting material, the band gap between conduction and valance electrons plays a vital role in the generation of reactive oxygen species (ROS), which bring about conformational changes/oxidant injury to the surface of the microorganism membrane. The ZnO nanoparticles, which have positive zeta potential, easily rupture the cell membrane of Escherichia coli (gram negative) on contact and release Zn2+ ions, which cause lysosomal and mitochondrial damages. Finally, it is leading to the death of bacterial cells.

The surface defects and morphological changes of ZnO nanoparticles do not play a significant role in the antibacterial activity. That the antibacterial activity depends on the particle size, with an increase in antibacterial activity observed for decreasing size of nanoparticles.

Recently the Krishna Raghupathi et al also reported the properties of antibacterial activity against particles size. This report described the antibacterial activity of ZnO nanoparticles in the range from 212 nm to 12 nm particle size. The antibacterial activity of ZnO nanoparticles is inversely proportional to the size of the nanoparticles. **(**Krishna Raghupathi et al, 2011; Selvam & Sundrarajan et al, 2012)

### **3.3.1 Plasma sputtering**

However, conventional finishing techniques applied to textiles (dyeing, stain repellence, flame retardance, antibacterial treatments) generally use wet-chemical process steps and produce a lot of wastewater. Plasma treatment, on the other hand, is a dry and eco-friendly technology, which offers an attractive alternative to add new functionalities such as water repellence, long-term hydrophilicity, mechanical, electrical and antibacterial properties as well as biocompatibility due to the nano-scaled modification on textiles and fiber. Moreover, the bulk properties as well as the touch of the textiles remain unaffected.( Shahidi et al, 2010)

In recent years, innovative aspects on the use of coated fabrics have been revealed. Coatings can be applied onto fabrics thus influencing their light reflectivity, electrical conductivity, thermal insulation or for serving decorative purposes. Anti-microbial properties of fabrics are of elevated importance if they are exposed to enhanced biological activity such as in close contact to soil or in a humid environment. In the investigations presented here, the antimicrobial effectiveness of thin films is assessed and the effort of additional finishing for sufficient material protection is determined.

In recent years, physical vapor deposition (PVD) has been applied to modify textile materials due to its inherent merits, such as environmental friendly, various functions and solvent-free process. Sputter coating is one of the most commonly used techniques in PVD, which has been widely used in glass, ceramic and micro-electronic industries.

Sputter coating produces very thin metallic or ceramic coatings on to a wide range of substrates, which can be either metallic or non-metallic in different forms. Sputter coating has also been used to coat textile materials for technical applications. The sputtered atoms have a high energy and when they impinge on any surface, they form a surface coating. The adhesion between the coated layer and the substrate plays a very important role in various

The ZnO nanoparticles have been measured to possess probable biological applications as efficient antimicrobial agents, drug carriers, bioimaging probes and possessing cytotoxic behavior for the treatment of cancer. Being a semiconducting material, the band gap between conduction and valance electrons plays a vital role in the generation of reactive oxygen species (ROS), which bring about conformational changes/oxidant injury to the surface of the microorganism membrane. The ZnO nanoparticles, which have positive zeta potential, easily rupture the cell membrane of Escherichia coli (gram negative) on contact and release Zn2+ ions, which cause lysosomal and mitochondrial damages. Finally, it is

The surface defects and morphological changes of ZnO nanoparticles do not play a significant role in the antibacterial activity. That the antibacterial activity depends on the particle size, with an increase in antibacterial activity observed for decreasing size of

Recently the Krishna Raghupathi et al also reported the properties of antibacterial activity against particles size. This report described the antibacterial activity of ZnO nanoparticles in the range from 212 nm to 12 nm particle size. The antibacterial activity of ZnO nanoparticles is inversely proportional to the size of the nanoparticles. **(**Krishna Raghupathi et al, 2011;

However, conventional finishing techniques applied to textiles (dyeing, stain repellence, flame retardance, antibacterial treatments) generally use wet-chemical process steps and produce a lot of wastewater. Plasma treatment, on the other hand, is a dry and eco-friendly technology, which offers an attractive alternative to add new functionalities such as water repellence, long-term hydrophilicity, mechanical, electrical and antibacterial properties as well as biocompatibility due to the nano-scaled modification on textiles and fiber. Moreover, the bulk properties as well as the touch of the textiles remain unaffected.( Shahidi et al, 2010) In recent years, innovative aspects on the use of coated fabrics have been revealed. Coatings can be applied onto fabrics thus influencing their light reflectivity, electrical conductivity, thermal insulation or for serving decorative purposes. Anti-microbial properties of fabrics are of elevated importance if they are exposed to enhanced biological activity such as in close contact to soil or in a humid environment. In the investigations presented here, the antimicrobial effectiveness of thin films is assessed and the effort of additional finishing for

In recent years, physical vapor deposition (PVD) has been applied to modify textile materials due to its inherent merits, such as environmental friendly, various functions and solvent-free process. Sputter coating is one of the most commonly used techniques in PVD,

Sputter coating produces very thin metallic or ceramic coatings on to a wide range of substrates, which can be either metallic or non-metallic in different forms. Sputter coating has also been used to coat textile materials for technical applications. The sputtered atoms have a high energy and when they impinge on any surface, they form a surface coating. The adhesion between the coated layer and the substrate plays a very important role in various

which has been widely used in glass, ceramic and micro-electronic industries.

leading to the death of bacterial cells.

Selvam & Sundrarajan et al, 2012)

sufficient material protection is determined.

**3.3.1 Plasma sputtering** 

nanoparticles.

applications of the sputter coated materials.( Scholz et al, 2005; Wei et al, 2008; Hegemann et al, 2007; Yuranova et al, 2003 ; Brunon et al, 2011 ; Yuranova et al, 2003)

The advantages of sputtering are the following: simple process, time saving, environmental friendly, and a resulting coating with superior adhesion to substrates.

Deposition of copper on the surface of cotton samples was performed in DC magnetron sputtering, made by Plasma Physics Research Center (Tehran, Iran), by using the setup schematically presented in Figure 3. Copper post cathode was used; also as it can be seen that samples were placed on the anode, and exposed to argon plasma in a cylindrical glass tube. The chamber was evacuated to a pressure of 10-5 Torr, using rotary and diffusion pumps, and then argon gas was introduced into the chamber up to a pressure of 0.05 Torr. Voltage was kept at 950 V and the discharge current was about 220 mA.

Fig. 3. The schematic view of Plasma sputtering system

Copper particles were deposited on the surface of cotton samples, and the antibacterial has been developed, through incorporation of copper particles on fabric surfaces. The antibacterial properties of the fabrics were connected with the presence of copper on their surface. After plasma treatment, the physical and chemical properties of the fabrics have been examined by surface analysis methods and textile technology tests. Also the antibacterial efficiency was determined by the Halo method.

The agar culture medium is transparent, when the bacterium is inhibited from growth, a transparent area in the form of a halo around the fabric will be observed.

There is no halo observed for untreated cotton fabric. This control test shows that the original cotton fabric does not have any antibacterial properties. Figure 4 illustrate the test results for the untreated and cotton-coated fabric for 30 seconds with S. aureus. (Shahidi et al, 2007; Ghoranneviss et al, 2011)

Antibacterial Agents in Textile Industry 397

Fig. 6. The bacterial counting test for untreated wool with S.aureus

Fig. 7. The bacterial counting test for silver coated wool with E.Coli

In the other research work, wool samples have been sputtered by silver particles. The antibacterial counting test was used and the results are shown in Figure 5-8. Both E.coli and S.aureus were used as a bacterial medium. As it is seen, in case of untreated samples, the bacterial colonies cover the completely the agar plate. But after Ag sputtering less amount of bacteria growth in agar plate. However this effect is more significant in case of using s.aureus as bacteria. (Shahidi et al, 2007; Ghoranneviss et al, 2011)

Fig. 5. The bacterial counting test for untreated wool with E. coli

Fig. 4. The inhibition zone of S.aureus around untreated and copper coated cotton.

s.aureus as bacteria. (Shahidi et al, 2007; Ghoranneviss et al, 2011)

Fig. 5. The bacterial counting test for untreated wool with E. coli

In the other research work, wool samples have been sputtered by silver particles. The antibacterial counting test was used and the results are shown in Figure 5-8. Both E.coli and S.aureus were used as a bacterial medium. As it is seen, in case of untreated samples, the bacterial colonies cover the completely the agar plate. But after Ag sputtering less amount of bacteria growth in agar plate. However this effect is more significant in case of using

Fig. 6. The bacterial counting test for untreated wool with S.aureus

Fig. 7. The bacterial counting test for silver coated wool with E.Coli

Antibacterial Agents in Textile Industry 399

It comprises copolymers of glucosamine and N-acetyl glucosamine and has a combination of many unique properties, such as non-toxicity, biocompatibility and biodegradability. Chitosan has got wide application in textile dyeing and finishing as a substitute for the various chemicals used in textile processing . It has been used as a pretreatment agent in dyeing of cotton, in textile printing, wool dyeing and shrink proofing and in durable press

It is known that chitosan derivatives with quaternary ammonium groups possess high efficacy against bacteria and fungi. It is now widely accepted that the target site of these cationic polymers is the cytoplasmic membrane of bacterial cells. (Ignatova et al, 2007;

Chitosan-based core-shell particle, with chitosan as the shell and a soft polymer as the core, has been designed as a novel antibacterial coating for textiles by Ye et al. The core-shell particles were synthesized via a graft copolymerization of n-butyl acrylate from chitosan in aqueous solution. Properties of the particles, including composition, particle size and distribution, surface charge as well as morphology, were characterized. The treatment of cotton with poly(n-butyl acrylate) (PBA)-chitosan particles confers the fabric with excellent antibacterial property. It is well recognized that chitosan has good antimicrobial activity, especially against the growth of Staphylococcus aureus (S. aureus). Figure 9 shows the result of treated and untreated specimens. As expected, the untreated fabric gave a negligible antibacterial activity of less than 5% while all finished cotton showed over 99% bacterial

Thus chemical modification of the chitosan through the graft copolymerization does not affect its antimicrobial property**. (**Ye et al, 2005) Also the TEM images of core-shell particles

Fig. 9. Comparison of bacterial reduction before and after coating cotton fabrics with

chitosan-PBA particles or chitosan solution (after 1 h shaking).

finish. (Gupta & Haile, 2007; Knill et al, 2004; Fan et al, 2006)

Ignatova et al, 2006)

reduction.

are shown in Figure 10.

Fig. 8. The bacterila counting test for silver coated wool with S.aureus
