Facile interfacial synthesis of silica/titania mesoporous microcapsules via in situ miniemulsification process

A facile and flexible technique is described for the fabrication of silica/titania microcapsules from stable miniemulsion droplets. Bis (2,4-pentanedionato)-bis (2-propanolato) titanium (IV) (PDPT), tetraethoxysilane (TEOS) and γ-(trimethoxysilyl) propyl methacrylate and/are restricted in miniemulsion microreactor droplets via a miniemulsification process, are stabilised by cetyltrimethylammonium bromide and hexadecane. After the addition of triethylamine, silica/titania shells are formed in situ by the hydrolysis-condensation at the interfaces of miniemulsion droplets because of the dramatical decrease of the original TEOS and PDPT volume. The mesoporous silica/titania microcapsules are about 1 μm with average pore size of 5.2 nm and the Brunauer-Emmett-Teller surface area is 312.0 cm²/g. The biocompatible and mesoporous nature of microcapsules promises an ideal vehicle for catalyst and drug delivery.