Synthesis and antimicrobial study of silver-kaolinite nanocomposites B. Cabal 1

Microorganism produce a wide range of diseases and they are responsible of contamination of drinking water and the decay of fruits and vegetables [1, 2]. Pathogenic microorganisms with resistance to various antimicrobial agents have risen over the last several years, resulting in increase in morbidity and mortality and overall treatment cost. In this regard, inorganic bactericides have attracted special interest due to their chemical stability, long life and heat resistance [3, 4]. Silver, known as a desinfectant for many years, has a broad spectrum of antibacterial activity. Silver nanoparticles show efficient antimicrobial properties compared to other silver salts due to their extremely large surface area and low solubility, which provides better contact with micro-organisms. Silver nanoparticles in most studies are suggested to be non-toxic in low concentrations, but in high concentration could have toxic effects. In the present work, a nanocomposite of kaolinite with a low content (1 wt % Ag) of silver nanoparticles is presented. Two different methods were followed to deposited Ag nanoparticles in a controlled way on the kaolinite surface. In the first procedure, the precursor is reduced thermally, while in the second there is a chemical reduction employing in this case sodium borohydride as a reductor agent. In both cases, the first step is the preparation of