Development of white antibacterial pigment based on silver chloride nanoparticles and mesoporous silica and its polymer composite

We report the synthesis of silver chloride nanoparticles inside the pores of a mesoporous silica, SBA-15. The nanoparticles were formed by an ion exchange reaction of AgNO3 incorporated inside the pores with a HCl vapor. The incorporation of AgNO3 into the SBA-15 pores and its conversion into silver nanoparticles were proven by low angle X-ray diffraction, infrared spectroscopy, nitrogen adsorption-desorption experiments, and transmission electron microscopy. The resultant nanocomposite material between AgCl and SBA-15 (AgCl@SBA-15) was processed with polypropylene to form a polymer composite. The silver chloride nanoparticles inside the SBA-15 pores are found to be stable against reduction by photons and/or heat. Therefore, both AgCl@SBA-15 and its polymer composite have high antibacterial activity and maintain white color, enabling a variety of antibacterial consumer goods in various colors. (C) 2009 Elsevier Inc. All rights reserved.