Influence of silica forming media on the synthesis of hollow silica microspheres

Abstract

The nature of core template has significant influences on the synthesis of hollow silica microspheres via the polystyrene (PS) beads templating route. Our present study indicates that the silica forming medium determines whether a surfactant is needed in the synthesis. It is shown that in a medium which itself gives discrete silica microspheres, hollow silica microspheres can only be templated by PS beads with the addition of cetyltrimethylammonium bromide surfactant. In contrast, in a medium which itself generates highly aggregated silica microspheres, hollow silica microspheres successfully templated by PS beads without any cationic surfactant. A unified mechanism for the formation of hollow silica shells with and without the surfactant is proposed.