Evaluación de las propiedades bactericidas de tejidos impregnados con nanopartículas de plata

Abstract

The bactericidal properties of silver nanoparticle impregnated cotton fabrics were evaluated in this work. First, silver nanoparticles were synthesized by the polyol process, reducing silver nitrate with ethylene glycol. The effect of the temperature and the amount of polyvinylpyrrolidone (PVP) stabilizing agent were studied. The temperatures used were 100, 120 and 140 °C. Three PVP/AgNO3 weight percent ratios were established in order to study the influence of these two agents in the process: 0, 0.25 and 0.50 (% w/w). Spherical nanoparticles with size between 15 and 30 nm were obtained by working with 120°C and PVP/AgNO3 de 0.50 (% w/w). They were observed by transmission electronic microscopy. Two silver nanoparticle solutions, with concentrations of 10 and 20 ppm, were prepared to impregnate 130 g/m2 and 132 g/m2 cotton fabrics using the pad-dry-cure technique. To analyze their bactericidal properties, the fabrics were subjected to Gram positive bacteria Staphylococcus aureus 25923. The tests showed that the 130 g/m2 cotton fabric impregnated with 10 and 20 ppm solutions had better bactericidal properties due to the reduction of bacterial colonies in 98.86 % and 99.94 %, respectively. A stabilization analysis of 10 washing cycles was performed using the 130 g/m2 cotton fabric impregnated with the 10 ppm solution. The bactericidal analyses showed that nanoparticles migrated from the fabrics, resulting in a lack of bacterial reduction potential. The use of an acrylic binder was proposed in order to evaluate its effect in the presence of nanoparticles over the fabrics. The binder treated impregnated fabrics were subjected to 10 washing cycles and the results showed that bacterial reduction improved by a 50 % average.