Recent Advances in Development of Antimicrobial Textiles
141
analyzed [73, 74]. The l-cysteine could be covalently attached onto textile substrate
via esterification of OH-groups present at the surface of cellulosic material. On the
other hand, due to coordinate covalent bond formation between nanoparticles and
l-cysteine made it possible to adhere nanoparticles tightly with the textile [75]. The
l-cysteine have also been applied on wool fabrics to preserve its quality and to make
it antibacterial for different medical and healthcare applications [76].
7.2 Inorganic Antibacterial Bacterial Agents for Textiles
Killing of bacteria is referred as biological self-cleaning. Biological self-cleaning
textile is capable of killing bacteria attached to them. In last few decades trend is
moving towards antibacterial products because the environment is full of microbe.
There is a great need to develop products that offer protection against microbes.
Nanomaterials in particular nanoparticles of inorganic metals and metal oxides are
extensively used to functionalize natural, synthetic and regenerated polymers because
of their effective antibacterial activity against different bacterial strains. Researchers
worked on different polymers and different antibacterial agents to give antibacterial
property to textiles.
The antibacterial activity of contact active surfaces is mainly due to its topography.
If the surface has nanoroughness like presence of nanorods, nanoparticles or any other
nanostructure, the attaching bacteria on this surface will be killed due to penetration
of these structures into membranes which leads to its disintegration. This mechanism
is valid for all type of nanostructures whether they are inherently antibacterial or not.
Like surface structures of many butterflies are not inherently antibacterial but their
morphologies make them antibacterial [77, 78].
Nanoparticles can be applied by two methods to modify fabric as antibacterial.
Generally, first method involves direct deposition of metal NPs on the textile surface by some electrostatic force. In this methods colloidal metal nanoparticles are
prepared using some reducing agent to reduce metallic salt to metal nanoparticles.
Then polymeric textiles are directly immersed in colloidal solution containing metal
NPs and are deposited on fibres as shown in Fig. 10b [79]. Sometimes surface modification of textile is done to enhance surface energy, to make surface rough so that
adhesion/affinity between fibre surface and metal nanoparticles can be enhanced to a
greater level. Plasma treatment [80], corona treatment [81], and enzyme treatments
[82] are done for this purpose. In second method, metal ions are adsorbed at the surface, then, these ions are converted to metal NPs by UV radiation [83], heat treatment
[84] or by some chemical reduction method.
Currently NPs of silver [85], titanium dioxide [86, 87], silver bromide, zinc oxide
[88], gallium, gold, carbon nanotubes and copper oxide are being used as biocide
releasing antibacterial agents (Fig. 11) that kill bacteria before their access to the
surface.
141
analyzed [73, 74]. The l-cysteine could be covalently attached onto textile substrate
via esterification of OH-groups present at the surface of cellulosic material. On the
other hand, due to coordinate covalent bond formation between nanoparticles and
l-cysteine made it possible to adhere nanoparticles tightly with the textile [75]. The
l-cysteine have also been applied on wool fabrics to preserve its quality and to make
it antibacterial for different medical and healthcare applications [76].
7.2 Inorganic Antibacterial Bacterial Agents for Textiles
Killing of bacteria is referred as biological self-cleaning. Biological self-cleaning
textile is capable of killing bacteria attached to them. In last few decades trend is
moving towards antibacterial products because the environment is full of microbe.
There is a great need to develop products that offer protection against microbes.
Nanomaterials in particular nanoparticles of inorganic metals and metal oxides are
extensively used to functionalize natural, synthetic and regenerated polymers because
of their effective antibacterial activity against different bacterial strains. Researchers
worked on different polymers and different antibacterial agents to give antibacterial
property to textiles.
The antibacterial activity of contact active surfaces is mainly due to its topography.
If the surface has nanoroughness like presence of nanorods, nanoparticles or any other
nanostructure, the attaching bacteria on this surface will be killed due to penetration
of these structures into membranes which leads to its disintegration. This mechanism
is valid for all type of nanostructures whether they are inherently antibacterial or not.
Like surface structures of many butterflies are not inherently antibacterial but their
morphologies make them antibacterial [77, 78].
Nanoparticles can be applied by two methods to modify fabric as antibacterial.
Generally, first method involves direct deposition of metal NPs on the textile surface by some electrostatic force. In this methods colloidal metal nanoparticles are
prepared using some reducing agent to reduce metallic salt to metal nanoparticles.
Then polymeric textiles are directly immersed in colloidal solution containing metal
NPs and are deposited on fibres as shown in Fig. 10b [79]. Sometimes surface modification of textile is done to enhance surface energy, to make surface rough so that
adhesion/affinity between fibre surface and metal nanoparticles can be enhanced to a
greater level. Plasma treatment [80], corona treatment [81], and enzyme treatments
[82] are done for this purpose. In second method, metal ions are adsorbed at the surface, then, these ions are converted to metal NPs by UV radiation [83], heat treatment
[84] or by some chemical reduction method.
Currently NPs of silver [85], titanium dioxide [86, 87], silver bromide, zinc oxide
[88], gallium, gold, carbon nanotubes and copper oxide are being used as biocide
releasing antibacterial agents (Fig. 11) that kill bacteria before their access to the
surface.