Patent ID: 7976812
Filing Date: 2011-07-12
Classification: B01J,C01B,C01P,C09C,Y10T

Abstract:
1. A method for producing a core-shell silica, which comprises: dispersing substantially non-porous silica core particles having a sphericity of at least 0.8 and a coefficient of variation of at most 0.2 in a dispersion medium containing an alcohol and water in the presence of a surfactant to prepare a dispersion, wherein the surfactant is an alkylammonium halide or an alkylamine; adding a silica precursor to the dispersion and reacting the silica precursor under a condition of pH of from 8 to 13 to form a shell precursor containing silica and the surfactant on the surface of each silica core particle; and removing the surfactant from the shell precursor to form a porous shell.