Preparation of mesoporous silica spheres with high surface area

Mesoporous materials have attracted much attention not only due to porous features for adsorbents and catalysts but also due to electronic, magnetic, and optical properties for advanced devices. Silica spheres with mesoporous structures have potential applications in drug storage and release, confined-space catalysis, separation and energy storage. In this study, mesoporous silica spheres were synthesized by a sol–gel/emulsion approach, in which cetyltrimethylammonium bromide (CTAB) surfactant was employed to stabilize and direct the hydrolysis of oil droplets of tetraethoxysilane (TEOS). In this method, the mixture of water and ethanol was used instead of water in the conventional oil-in-water emulsion system to improve the stability of the oil droplets, thus allowing the preparation of silica spheres with improved size distribution. The diameters of the silica spheres were in the range from 300 to 400 nm. BET surface areas of the silica spheres were determined to be high up to 1208 m2g-1 and their pore size were around 2.66 nm as determined by BJH method.

Keywords:

Mesoporous , Silica spheres , Sol-gel , Emulsion , CTAB