溶胶凝胶-模板技术合成负载型中孔SiO_2膜

SUPPORTED MESOPOROUS SiO_2 MEMBRANES SYNTHESIZED BY SOL-GEL-TEMPLATE TECHNOLOGY

将溶胶 -凝胶技术与模板技术结合起来 ,分别以TEOS和Na2 SiO3为有机和无机硅源 ,C1 2 H2 5(CH3) 3N+ Cl- (DTAC)为模板剂 ,制备了两类负载型中孔SiO2 膜 .SEM ,XRD ,IR ,TG -DTA ,氮吸附和气体渗透性能测试装置对其进行了表征 .结果表明 :两类膜成膜情况良好 ,硅溶胶与模板剂形成键联型交联 ,由有机硅源制备的SiO2 膜晶相和非晶相共存 ,平均孔径 4.2nm ,最高有机分解温度 2 97℃ .而由无机硅源制得的SiO2 膜全部为晶态结构 ,平均孔径为 6.0nm ,最高有机分解温度 2 75℃ .气体在这两类膜中的渗透均由Knudsen扩散控制 .

Two types of supported mesoporous SiO2 membranes were prepared with organic silicon source (tetraethoxy silane, TEOS), inorganic silicon source (Na2SiO3) and template agents C12H25(CH3)3N+Cl- by the sol-gel method combined with the template technology. The membranes were characterized by SEM, XRD, IR and TG-DTA, nitrogen absorption and gas permeability measurement. The results show that the two membranes are well formed and bonds are formed between silicon source and template agents. Both crystalline phase and amorphous phase exist in the membranes prepared from TEOS, whose average pore diameter is 4.2 nm and the maximum organic decomposition temperature is 297°C. However, the membranes prepared from Na2SiO3 only have crystalline phase, with average pore diameter of 6.0 nm and the maximum organic decomposition temperature of 275°C. The gas permeability of the two types of membranes is controlled by the Knudsen diffusion.