中空纤维担载无机分离膜的制备和表征

【作者】 缪丽娜；

【导师】 王连军； 李健生；

【作者基本信息】 南京理工大学 ， 环境工程， 2004， 硕士

【摘要】 本论文采用溶胶凝胶法在氧化铝中空纤维支撑体上制备SiO₂介孔膜、SiO₂微孔膜、Al₂O₃：-SiO₂复合膜。通过扫描电镜、气体渗透装置对膜的微观结构、完整性及其对气体的选择性进行了研究；采用热重分析仪、差热分析仪、红外光谱、X射线衍射和等温N₂吸附考察了样品的稳定性、组成、晶相和孔径及其分布。结果表明：介孔SiO₂膜的比表面积可达919.75m²／g，孔容达0.4346ml／g，最可几孔径小于3nm；膜较完整、无大缺陷，室温、0.12MPa下N₂的气体渗透通量为1.81×10^-5mol／（m²·s·Pa），H₂和N₂的分离因子为2.431。微孔SiO₂膜的气体渗透通量数量级为10^-6mol／（m²·s·Pa）。不同比例的复合膜表面完整无针孔，在0.1MPa，条件下对氢／氮的分离因子为3.03，说明气体通过膜的扩散以Knudsen扩散传质为主，非担载Al₂O₃：-SiO₂复合膜的比表面积为294.85m²／g，总孔容为0.2778mL／g，最可几孔径小于3nm。更多还原

【Abstract】 Mesoporous silica membranes , microporous silica membranes and Al203,-Si02 composite membranes on hollow fiber alumina supports were prepared by a sol-gel process. The microstructure of the membranes was analyzed by sanning electro microscopy. Their permeability and gas separate ability were investigated by a gas separation installation. The thermal stability, composition, crystalline phase and pore size distribution of powder samples were studied by thermal gravimetric analysis, differential thermal analysis, FT-IR spectrograph, X-ray diffraction and isothermal nitrogen adsorption, respectively. The results showed that BET specific area of mesoporous silica membranes reached 919. 75m2/g and the total pore volume’ was 0.4346ml/g. The most probable pore diameter was less than 3nm. Mesoporous silica membranes were free from large defects, the gas permeance of N2 and the separation factor of H2/N2 measured under room temperature and a pressure of 0.12MPa were 1.81Xl0-5mol/(m2 s Pa) and 2.431, respectively. For the microporous silica membranes, gas permeance reached the order of lO-6mol/(m2 s’Pa). Different mole ratios of Al203-Si02 composite membranes were free from crack and distinct flaws. The separation factor of hydrogen to nitrogen measured at a pressure of 0. IMPa was 3.03. It was showed that the gas diffusion through the membrane is governed by Knudsen diffusion mechanism. The most probable pore diameter of an unsupported membrane after calcination at 600℃ was less than 3 nm, its specific surface area reached 294.85m2/g and .the total pore volume was 0. 2778mL/g.更多还原