Synthesis of silver nanoparticles
Nano Silver refers to the abiity to work at the molecular level, atom by atom, utilizing silver particles measured by nanometre, to capture excellent anti-microbial effects of silver. Nano silver is non poisonous, non allergic, effective lover a wide range of microorganism and it has long term activity.
Challenges: Colour, durability, uniform particle size
Application area: antimicrobial textiles, antistatic textiles, biosensors, cryogenic superconducting materials.
Antibacterial textiles with ~100% durable activity has been successfully developed in the lab. Dr. Sangeeta Paul has carried out detailed study on the effect of surfactants on shape and size of silver nanoparticles, stability and antibacterial activity. The technology had been transferred to an Industry and launched nationwide.
Effect of surfactants on shape and size of silver nanoparticles, stability and antibacterial activity
In the present era, people are concerned for the textiles with antimicrobial finish for protection against various pathogens in different sectors such as medical, technical, industrial, home furnishing, apparel etc. Nanosilver has shown high efficacy towards a wide range of microbes at a low concentration application. A strong correlation has been observed between the shape of nanostructures and their chemical, physical, catalytic and optical properties. Hence, the control of shape and size is technologically important as they may significantly influence the antimicrobial properties of nanosilver finish. In this study, size and shape of nanosilver have been controlled using a facile temperature controlled chemical reduction technique. The effect of both shape and size of silver nanoparticles on their dispersion stability and the antibacterial activity was investigated to obtain a highly potent nanosilver finish. Effect of different surfactants has been checked in terms of compatibility, particle size distribution and antibacterial activity. The antibacterial activity of the silver nanoparticles was evaluated against both gram positive bacterium Staphylococcus aureus and gram negative bacterium Escherichia coli with very low MBC (minimum bactericidal concentration) values. It was found that not only shape and size but also aggregating nature of very small nanoparticles in the dispersion media plays an important role in antimicrobial activity. Characterisation of aqueous dispersion of silver nanoparticle was done by UVvis spectroscopy, particle size analyser (DLS), Small Angle X-ray scattering.