Recent Advances in Development of Antimicrobial Textiles
143
because of larger surface area of NPs that provides more interaction of antibacterial agent with microbes per surface unit and due to penetration of nanostructures
in bacterial membranes. Silver has capability to attack the cell membrane and penetrate through it, causing malfunctioning of bacterial cell respiratory system, thus,
responsible for the cells death [93].
Shateri et al. studied the antibacterial activity of silver nanoparticles deposited on
cationized cotton. Cationic agent (3-chloro-2-hydroxy propyl trimethyl ammonium
chloride) in presence of alkali (NaOH) was used to make ordinary surface of cotton
fibers cationic and increased affinity of cotton fibers for AgNPs that showed outstanding antibacterial activity [94]. Yeo and Jeong [95] prepared bicomponent fibers
using polypropylene (PP) and AgNPs by melt spinning method. AgNPs were in core
and PP was spun as sheath of bicomponent fiber. But fibers didn’t show antibacterial
activity. The fibers in which silver was added in sheath showed superb antibacterial
property.
Dubas et al. [96] worked on layer by layer deposition of Ag NPs which
were stabilized with capping agent poly (methacrylic acid) PMA. The layer of
anionic poly (methacrylic acid) capped AgNPs was immobilized by cationic
poly(diallyldimethylammonium chloride) when silk and nylon fibers were coated
with these layers. Thus, rendering these fibers as highly antibacterial for different
applications. Wool fibres were also investigated for their antibacterial property by
direct deposition of AgNPs, at fibre surface reduction of metal salt was done by
reducing agent and trisodium citrate (TSC) was used as linker that bound AgNPs
with amino acid of keratin that is wool fibres protein. Along with antibacterial activity, AgNPs also gave surface plasmon resonance optical effect, enhanced electrical
conductivity and antistatic property to fibres [97]. In another approach AgNps were
applied on surface of silk fibres by hydrogen bonding [86].
AgNPs were fabricated by in situ direct metallization technique. The cellulose
membranes were treated with Aqueous AgNO 3 solution. After washing, Ag
+ ions
containing membranes were treated with solution of reducing agents and some colloid
protector under certain process conditions. These composite fibers showed superb
antibacterial activity [87]. To enhance the antibacterial effect, combination of different antibacterial agents have also been used. Silver loaded chitosan nanoparticles
when applied to textile showed enhanced antibacterial activity compared with only
chitosan nanoparticles applied textile because synergistic antimicrobial effect against
S. aureus bacteria was showed by silver loaded chitosan nanoparticles [98].
Surface modification of textile substrates with AgNPs and antibacterial activity
was explored by using sodium hydroxide at different concentrations. Alkali treated
cotton fabric was immersed in silver nitrate solution (AgNO 3 ) and then chemical
reduction caused in situ AgNPs on fabric surface. Higher the concentration of NaOH
more was silver content at surface. Homogeneously distributed NPs at treated fabric
surface exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus. That procedure gave durable, superficial, cost effective method for
higher silver content on textile surface [89].
143
because of larger surface area of NPs that provides more interaction of antibacterial agent with microbes per surface unit and due to penetration of nanostructures
in bacterial membranes. Silver has capability to attack the cell membrane and penetrate through it, causing malfunctioning of bacterial cell respiratory system, thus,
responsible for the cells death [93].
Shateri et al. studied the antibacterial activity of silver nanoparticles deposited on
cationized cotton. Cationic agent (3-chloro-2-hydroxy propyl trimethyl ammonium
chloride) in presence of alkali (NaOH) was used to make ordinary surface of cotton
fibers cationic and increased affinity of cotton fibers for AgNPs that showed outstanding antibacterial activity [94]. Yeo and Jeong [95] prepared bicomponent fibers
using polypropylene (PP) and AgNPs by melt spinning method. AgNPs were in core
and PP was spun as sheath of bicomponent fiber. But fibers didn’t show antibacterial
activity. The fibers in which silver was added in sheath showed superb antibacterial
property.
Dubas et al. [96] worked on layer by layer deposition of Ag NPs which
were stabilized with capping agent poly (methacrylic acid) PMA. The layer of
anionic poly (methacrylic acid) capped AgNPs was immobilized by cationic
poly(diallyldimethylammonium chloride) when silk and nylon fibers were coated
with these layers. Thus, rendering these fibers as highly antibacterial for different
applications. Wool fibres were also investigated for their antibacterial property by
direct deposition of AgNPs, at fibre surface reduction of metal salt was done by
reducing agent and trisodium citrate (TSC) was used as linker that bound AgNPs
with amino acid of keratin that is wool fibres protein. Along with antibacterial activity, AgNPs also gave surface plasmon resonance optical effect, enhanced electrical
conductivity and antistatic property to fibres [97]. In another approach AgNps were
applied on surface of silk fibres by hydrogen bonding [86].
AgNPs were fabricated by in situ direct metallization technique. The cellulose
membranes were treated with Aqueous AgNO 3 solution. After washing, Ag
+ ions
containing membranes were treated with solution of reducing agents and some colloid
protector under certain process conditions. These composite fibers showed superb
antibacterial activity [87]. To enhance the antibacterial effect, combination of different antibacterial agents have also been used. Silver loaded chitosan nanoparticles
when applied to textile showed enhanced antibacterial activity compared with only
chitosan nanoparticles applied textile because synergistic antimicrobial effect against
S. aureus bacteria was showed by silver loaded chitosan nanoparticles [98].
Surface modification of textile substrates with AgNPs and antibacterial activity
was explored by using sodium hydroxide at different concentrations. Alkali treated
cotton fabric was immersed in silver nitrate solution (AgNO 3 ) and then chemical
reduction caused in situ AgNPs on fabric surface. Higher the concentration of NaOH
more was silver content at surface. Homogeneously distributed NPs at treated fabric
surface exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus. That procedure gave durable, superficial, cost effective method for
higher silver content on textile surface [89].