模板法合成六方介孔SiO_2  

Synthesis of Highly Ordered Hexagonal Mesoporous Silica

作　　者：闫欣[1] 韩书华[1] 侯万国[1] 党文修[1] 许军[1] 于小娟[1] 

机构地区：[1]山东大学胶体与界面化学教育部重点实验室,济南250100

出　　处：《应用化学》2004年第9期946-949,共4页Chinese Journal of Applied Chemistry

摘　　要：合成了低聚季铵盐表面活性剂。以此为模板剂 ,在中性条件下合成出结构高度有序的介孔SiO2 材料MCM 4 1。考察了表面活性剂与硅酸盐的比例对产物结构与表面性质的影响。XRD结果表明 ,随着表面活性剂与硅酸盐比例的增加 ,介孔材料孔道有序性增加。表面活性剂与硅酸盐摩尔比例大于 1∶35时可以得到高度有序的MCM 4 1材料 ,其中n(surf)∶n(Si) =1∶8时 ,产物的有序性最高。表面活性剂与硅酸盐的比例对晶胞参数 (a0 )没有显著影响 ,a0 值在 4 30 4 4 3nm之间。N2 吸附实验表明 ,随着表面活性剂与硅酸盐比例的增加 ,产物的BET表面积、孔体积随之增加。在n(surf)∶n(Si) =1∶35时 ,吸附等温线类型由Ⅱ型向Ⅳ型转化。表面活性剂与硅酸盐的比例对最可几孔径和孔壁厚度均没有显著影响 ,二者分别在 3 74 3 76nm和 0 5 4 0 6The highly ordered mesoporous silica with hexagonal symmetry was synthesized by using an oligomeric surfactant as template under neutral condition. The effect of different molar ratio of surfactant to silicate on the surface structure of the product was studied by small-angle X-ray diffractometry. The results showed that the structure of the resulting product has hexagonal symmetry and the ordering of pore structure increased with the improving of the molar ratio of surfactant to silica. When the molar ratio of surfactant to silica was more than 35, product with high quality could be obtained. The ordering of pore structure was the highest at 1∶8 of the ratio of surfactant to silica. Nitrogen adsorption-desorption test indicated that the BET surface and total pore volume of the product increased rapidly with the increase in the molar ratio of surfactant to silica and the type of N_(2) adsorption isotherm transformed from Ⅱ to Ⅳ at n(surf)∶n(Si)=1∶35. The molar ratio of surfactant to silica hardly showed effect on the most probable pore size and pore wall thickness which was found to be 3.74~3.76 nm and 0.54~0.69 nm, respectively.

关 键 词：介孔SIO2 六方结构 模板法 低聚表面活性剂 

分 类 号：O648[理学—物理化学]