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以正硅酸乙酯 [Si(OC2 H5) 4,TEOS]为前驱体制备SiO2 悬浮液 ,分别以甲基三乙氧基硅烷 [CH3Si(OC2 H5) 3,MTES]和二甲基二乙氧基硅烷 [(CH3) 2 Si(OC2 H5) 2 ,DDS]为前驱体制备硅氧烷聚合物溶液 ,通过混合法得到两种不同的甲基改性氧化硅凝胶 .测量了凝胶的散射强度 ,计算了凝胶的孔径分布、平均孔径DSAXS、界面层厚度E等参数 ,结合氮气吸附实验 ,分析了凝胶的孔结构 .发现SiO2 一次簇团被MTES聚合物或DDS聚合物连接为二次簇团时产生微孔 ,同时甲基随聚合物连接于凝胶骨架上形成与孔隙的界面层 ,界面层的存在对孔径和气体在孔内的吸附均有影响 .辅以透射电子显微镜观测 ,证实MTES和DDS对凝胶的孔结构有很大影响 .实验证明 ,用小角x射线散射技术研究甲基 凝胶孔结构是获得凝胶微观结构的有力工具 .
The SiO 2 suspension was prepared by using tetraethyl orthosilicate [Si (OC 2 H 5) 4, TEOS] as precursors. Methyltriethoxysilane [CH3Si (OC2 H5) 3, MTES] and dimethyl diethoxy Silicone polymer solution was prepared by using silane ([(CH3) 2 Si (OC2 H5) 2, DDS] as a precursor and two different methyl-modified silica gels were obtained by mixing method. The pore size distribution, mean pore size (DSAXS) and interface layer thickness (E) of the gel were calculated, and the pore structure of the gel was analyzed by nitrogen adsorption experiments. It was found that the primary cluster of SiO2 was connected by MTES polymer or DDS polymer The micropores were generated when the clusters were formed, and the interface between the methyl group and the polymer was connected to the gel matrix to form the interface layer with the pores. The presence of the interface layer had an effect on the pore size and gas adsorption in the pores. , Confirming that MTES and DDS have a great influence on the pore structure of the gel.Experiments show that the study of pore structure of methyl gel by small angle x-ray scattering is a powerful tool for obtaining gel microstructure.