Preparation of aqueous core/silica shell microcapsules.

Water core/silica shell microcapsules are prepared via the hydrolysis and subsequent polycondensation of tetraethoxysilane in a surfactant stabilised water-in-oil emulsion. The relationship between preparative conditions, including pH and silane concentration, has been related to final particle structure. Furthermore, the nature of the catalyst has been found to affect the mechanism by which the shells are formed, with an interfacial polymerisation proposed for ammonium hydroxide catalysed synthesis in agreement with previous reports and a new colloidosome assembly process for sodium hydroxide catalysis.