以正丙醇锆为前驱体,通过颗粒溶胶路线制备ZrO2溶胶,并以此溶胶制备出稳定的制膜液.采用浸浆法,经过一次涂膜,在平均孔径约为70nm的片状α-Al2O3支撑体上制备出完整无缺陷的孔径小于10nm的中孔ZrO2陶瓷膜,详细考察了烧成温度对ZrO2粉末和ZrO2中孔膜性能的影响.在450℃的烧成温度下制备出孔径约为7nm的ZrO2中孔膜,该膜对PEG的截留分子量为19500,在原料液侧压力为0.76MPa、温度(23±1)℃条件下,纯水渗透通量为30~35L/(m2·h).经HNO3(pH=2)和NaOH(pH=13)溶液动态腐蚀后的ZrO2中孔膜对PEG截留分子量的变化表明,所制ZrO2膜具有较高的耐酸碱腐蚀性能.
Preparation and characterization of mesoporous ZrO2 membrane with the pore sizes less than 10 nm were studied. A stable ZrO2 sol with a mean particle size about 100 nm was successfully synthesized with zirconium n-propoxide as precursor through a colloidal sol-gel route. PVA was selected as the drying chemical controlling additive to modulate the viscosity of sol suitable for membrane formation. Y(NO3)3-6H2O was used as a Y-precursor to form Y-stabilized ZrO2. Defect-free mesoporous ZrO2 membrane superimposed on α-Al2O3 support disk with a mean pore size of 70 nm was fabricated via dip-coating and subsequently calcined in the temperature range of 450-650 ℃. The effect of calcination temperature on the properties of unsupported ZrO2 membrane (powder) as well as the supported ZrO2 membranes was studied in detail. The molecular weight cut off (MWCO) and mean pore size of mesoporous ZrO2 membrane were in the range of 19 500-62 600 and 7.3-13 nm, respectively. The optimized membrane with an average pore size of 7.3 nm showed a MWCO value of 19 500 after heat treatment at 450 ℃. The corrosion resistance of ZrO2 membrane showed a relative high stability, as proved by the variation of MWCO of PEG after the membrane was treated with HNO3 and NaOH.