Preparation of Silver Nanoparticles in Reverse Micelles and Antibacterial Activity of Silver Modified-Paints

Silver particles having fine or ultrafine sizes are one of the fastest growing research interests with wide applications. Here we report the preparation method of silver modified paints which revealed antimicrobial activity against gram-negative bacteria Escherichia coli, gram-positive Staphylococcus aureus, yeast Saccharomyces cerevisiae and pathogenic fungi belonging to Candida family. In this work, we choose heptane and cyclohexane, as the oil phase for preparation nanometer sized metallic particles. We have also studied the effect of different silver precursors - silver nitrate, silver citrate and different surfactants: anionic AOT, non-ionic Triton X100, Span 80 and Tween 85 for stabilization of obtained silver colloids. UV-VIS spectrum contained a strong plasmon band near 410 nm, which confirmed silver ions reduction to Ag○ in microemulsion system or aqueous phases. Prepared samples contained from 500 to 2000 ppm of silver. The diameter size of silver nanoparticles was in the range from 16 nm to 82 nm and were stable for 3 months without precipitation.