TiO2中孔膜的制备及对Ni(2＋)的截留性能

PREPARATION AND Ni^(2+) RETENTION PROPERTY OF MESOPOROUS TiO_2 MEMBRANE

以钛酸四异丙酯为前驱体,通过颗粒溶胶路线制备出平均粒径为41nm的TiO2溶胶,并以此溶胶制备出稳定的制膜液。采用浸浆法,经过一次涂膜和在400～600℃烧成,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截留分子量小于10000的TiO2中孔膜。考察了烧成温度对非担载TiO2粉末和TiO2中孔膜性能的影响。结果表明:在400℃烧成3h可制备出孔径为4.7nm的TiO2中孔膜,其对PEG的截留分子量为8150,在0.8MPa,20℃下,纯水渗透通量为30L/(m2·h),对pH=3的Ni(NO3)2溶液的截留率达到95.14%。

A stable TiO2 sol with a mean particle size of 41 nm was successfully synthesized with titanium isopropoxide as precursor by a colloidal sol–gel route. Defect-free mesoporous TiO2 membranes with a relative molecular mass cut-off （MWCO） 10 000 were prepared on the α-Al2O3 disk with the mean pore size of 70 nm at a suitable sol viscosity via dip-coating for one time and subse-quently calcined in the temperature range of 400–600 ℃, and then characterized. The effect of the calcination temperature on the properties of unsupported TiO2 powders as well as the supported TiO2 membranes was investigated. The results show that TiO2 mem-brane with an average pore size of 4.7 nm and a MWCO of 8 150 can be obtained after calcined at 400 ℃ for 3 h. The filtering flux of pure water of this membrane is 30 L/（m2·h） at 0.8 MPa and 20 ℃ . The retention ratio of membrane for Ni（NO3）2 solution reaches a maximum value of 95.14% under a pH value of 3.