In Situ Silver Nanoparticles Production in a Polyelectrolite Net Recovering Polyester

Abstract

The aim of this work was to develop an antimicrobial polyester fiber by a polyelectrolyte deposition technique followed by silver nanoparticles formation in situ. Attached silver metallic nanoparticles (Ag°NPs) behave like a silver cations (Ag+) reservoir which are released to the environment when exposed to a wet medium, such as an open wound. Silver cations act against microorganisms by reacting with proteins from cellular membranes, denaturing them. This effect leads to alterations in organism growth and/or direct cellular death. Textiles were prepared by a layer by layer technique: two opposite charged polyelectrolytes, namely PAH (poly allylamine hydrochloride, positively charged) and PAA (polyacrylic acid, negatively charged), are deposited in an alternating manner in order to generate two bilayers (2PAH/PAA). Fibers are then immersed in a AgNO3 solution for a lapse adequate to allow Ag+ diffusion into the polymeric net, and subsequently they are chemicaly reduced by NaBH4 to form silver nanoparticles (Ag°NPs). The amount of silver thus deposited was measured to be in the range 5.5 - 7.7mg Ag/100 gr fiber. These textiles were then bio-tested against Staphylococus aureus, resulting in a significant growth inhibition of biomass.