Synthesis and antibacterial property of hollow SiO2/Ag nanocomposite spheres

This paper presents a novel and facile method to fabricate hollow silica/sliver (SiO2/Ag) nanocomposite spheres. In this approach, the monodisperse hollow SiO2 colloids bearing quantenary ammonium groups were prepared by dispersion polymerization combined sol-gel process and used as templates. The Ag+ ions were first adsorbed onto the surfaces of the hollow SiO2 beads via electrostatic interaction and then in situ reduced by the deprotonated silanol groups of the hollow SiO2 beads, no extra reducing agents or catalysts were added during the reduction process. TEM, SEM and EDX analyses indicated that Ag nanoparticles were successfully deposited onto the surfaces of hollow SiO2 beads. Some influencing parameters, such as the amount of quantenary ammonium groups in the inner wall of hollow SiO2 colloids, Ag+ ions concentration and reaction temperature, on the deposition of Ag nanoparticles onto SiO2 colloids were investigated. Preliminary antibacterial tests indicated that these hollow nanocomposite spheres showed excellent antibacterial ability. (C) 2011 Elsevier Inc. All rights reserved.