Preparation of Mesoporous Submicrometer Silica Capsules via an Interfacial Sol-Gel Process in Inverse Miniemulsion
作者：Zhihai Cao, Lizi Dong, Li Li, Yue Shang, Dongming Qi, Qun Lv, Guorong Shan
關(guān)鍵字：in Inverse Miniemulsion
論文來源：期刊
具體來源：Langmuir
發(fā)表時間：2012年
Mesoporous silica capsules with submicrometer
sizes were successfully prepared via the interfacial hydrolysis
and condensation reactions of tetraethoxysilane (TEOS) in
inverse miniemulsion by using hydrophilic liquid droplets as
template. The inverse miniemulsions containing pH-controlled
hydrophilic droplets were first prepared via sonication by using
poly(ethylene-co-butylene)-b-poly(ethylene oxide) (P(E/B)-
PEO) or SPAN 80 as surfactant. TEOS was directly
introduced to the continuous phase of an inverse miniemulsion.
The silica shell was formed by the deposition of silica on the surface of droplets. The formation of capsule morphology
was confirmed by transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). The
mesoporous structure was verified by nitrogen sorption measurements. The specific surface area could be tuned by the variation
of the amount of cetyltrimethylammonium bromide (CTAB) and TEOS, and the pore size by the amount of CTAB. The
influences of synthetic parameters on the particle size and morphology were investigated in terms of the amount of CTAB, pH
value in the droplets, TEOS amount, surfactant amount, and type of solvent with low polarity. A formation mechanism of silica
capsules was proposed.