强酸性介质中用三嵌段共聚物模板合成介孔硅基分子筛Ⅰ.样品的表征及共溶剂、共表面活性剂对样品颗粒外貌的影响

以聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物(P123)为模板剂，正硅酸乙酯为硅源，在强酸性介质中合成了一种孔径8.5nm、孔体积1.4cm^3/g的大孔径、二维六方对称结构的介孔硅基分子筛。采用SEM表征手段考察了共溶剂或共表面活性剂对介孔材料颗粒外貌的影响。结果表明，加入共溶剂N，N-二甲基甲酰胺(DMF)或共表面活性剂十六烷基三甲基溴化铵(CTAB)有利于介孔分子筛颗粒外貌向界面曲率增大的方向转变。并从介孔分子筛合成机理的角度对实验结果进行了详细的阐述。

SYNTHESIS OF MESOPOROUS SILICA WITH TRIBLOCK COPOLYMER AS THE TEMPLATE IN STRONG ACIDIC MEDIUM Ⅰ.Characterization of Samples and Effects of Cosolvent and Cosurfactant on Morphology of Mesoporous Silica

Highly ordered hexagonal mesoporous silica with large meosoporous size of 8. 5 nm and pore volume of 1.4 cm3/g was obtained under strong acidic media with tetraethyl-orthosilicate(TEOS) as the silicon source and triblock poly(ethylene oxide)-poly(propylene oxide)- poly(ethylene oxide) copolymer (P123) as the template. By means of scanning electron microscopy analysis (SEM), the effects of cosolvent or cosurfactant on morphology of mesoporous silica were investigated. The results showed that cosolvent or cosurfactant favored the formation of mesoporous silica with large surface curvature. A more curved rope-like material was prepared by using N, N-dimethylformamide (DMF) as cosolvent and clump-like material was formed by using hexadecyltriethylammon um bromide (CTAB) as cosurfactant. These results were explained further in terms of the synthesis mechanism.