NIE Lumei, ZHANG Junji, CHEN Jishi, WU Xiujuan, ZHAO Jingxun

(School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028)

Abstract:Based on the well -known St?ber method, silica microspheres were prepared by hydrolysis of tetraethoxy silane(TEOS) in mixed alcohol-water solvents using ammonia as a catalyst. Silica microspheres were obtained and the products were investigated by transmission electron microscopy (TEM). The results show that the monodispersed silicon dioxide spherical particles could be obtained in methanol, ethanol and n-butanol, while agglomerated silicon dioxide particles were formed in l-propanol. When the concentrations of TEOS and ammonia are increased, the particle sizes increase. Increasing the concentrations of water leads to little change in the silica particle sizes. The formation mechanisms of the resultant SiO₂ particles under different reaction conditions were carefully investigated and discussed.

Keywords:Stöber method, SiO₂ microsphere, monodisperse, formation mechanism