Abstract:

The optimized ZrO₂-TiO₂ composite colloidal sols with an average particle size of 3 nm were successfully synthesized via a modified colloidal sol-gel process by using water as solvent. Tubular α-Al₂O₃ membranes with a mean pore size of 5 nm were used as the intermediate layers. Defect-free ZrO₂-TiO₂ NF membranes were then fabricated on the interlayer surface via a dip-coating method. The ZrO₂-TiO₂ NF membranes with an average toplayer thickness of 200 nm showed the relatively high pure water permeability of about 23 L·m^-2·h^-1·(0.1 MPa)^-1 and low MWCO of about 600. Meanwhile, the ZrO₂-TiO₂ NF membranes indicated the high retention rates for Co²⁺, Sr²⁺ and Cs⁺ of 99.6%, 99.2% and 75.5% at the condition of low salts concentration, pH 3 and the transmembrane pressure of 0.9 MPa, respectively.

Key words: ceramic NF membranes, colloidal sols, ZrO₂-TiO₂, ions rejection

摘要：

以水为溶剂,采用改进的颗粒溶胶工艺,通过溶胶制备参数的调控优化,制备得到平均粒径为3 nm的ZrO₂-TiO₂复合颗粒溶胶。采用浸浆法,在平均孔径为5 nm的管式α-Al₂O₃底膜上,经过一次涂膜制备得到完整无缺陷的ZrO₂-TiO₂复合纳滤膜。ZrO₂-TiO₂复合纳滤膜的平均膜厚约为200 nm,纯水渗透率约为23 L·m^-2·h^-1·(0.1 MPa)^-1,对PEG的截留分子量为600。在pH 3,压力0.9 MPa的条件下,该膜对低浓度的Co²⁺、Sr²⁺、Cs⁺的截留率分别达到99.6 %、99.2 %和75.5 %。

关键词: 陶瓷纳滤膜, 颗粒溶胶, ZrO₂-TiO₂, 离子截留