莫来石陶瓷超滤膜的制备与表征

以正硅酸乙脂(TEOS)和Al(NO_3)_3·9H_2O为主要原料,聚乙烯醇(PVA)和甘油为添加剂,通过溶胶-凝胶法和浸渍涂覆法在管状α-Al_2O_3支撑体上制备莫来石陶瓷超滤膜.采用XRD、SEM、N2吸附法、渗透通量和截留分子量测定等方法对制备的超滤膜进行了结构和性能表征.结果表明,莫来石单相溶胶浓度为0.28 mol/L、pH=2.0、PVA和甘油加入量分别为1.5 wt;和6 wt;时,经三次涂覆和1200 ℃保温2 h烧成后,可获得表面结构均匀平整、不开裂的莫来石超滤膜;制备的莫来石超滤膜平均孔径为8.4 nm,厚度约1.8 nm,其平均纯净水渗透通量和聚乙二醇(PEG)截留分子量分别为46.8 L·m~(-2)·h~(-1)·(10~5 Pa)~(-1) 和9 kDa.

Preparation and Characterization of Novel Mullite Ceramic UF Membrane

Mullite ultrafiltration (UF) membrane was prepared on α-Al_2O_3 support by sol-gel method and slip casting technology, using Al(NO_3)_3·9H_2O and TEOS as main raw materials, PVA and glycerol as organic additives. The microstructure and properties of the prepared membrane were characterized by XRD, SEM, N2 isothermal absorption technique, permeate flux and molecular weight cut-off (MWCO) measurements. Results show that homogenous, smooth and crack free mullite UF membrane can be obtained after coated for three times using a single phase sol with a concentration of 0.28 mol/L, pH=2.0, 1.5 wt% PVA, 6 wt% glycerol, and sintered at 1200 ℃ for 2 h. The prepared membrane shows narrow pore size distribution and a mean pore size of 8.4nm. The pure water permeate flux and MWCO of the mullite membrane is about 46.8 L·m~(-2)·h~(-1)·(10~5 Pa)~(-1) and 9 kDa, respectively.