Synthesis of titania-coated silica nanoparticles using ono-ionic water-in-oil

Titania (TiO2) nanocoating on silica (SiO2) particles was obtained by contr olled hydrolysis of titanium alkoxide precursors. Monodisperse spherical si lica particles prepared by Stober method were used as the support. Isolated silica particles with uniform titania nanocoating were obtained by reactin g appropriate alkoxide and water at ambient temperature. The thickness and uniformity of TiO2 coating were controlled by adjusting the concentrations of reactants and the amount of added SiO2. The samples were characterized u sing electron microscopy and electrophoresis. The surface coverage was esti mated using isoelectric point (IEP) data. (C) 2001 Elsevier Science B.V. Al l rights reserved.