TiO_2溶胶杂化改性PPESK超滤膜的制备及性能

Preparation and characterization of PPESK ultrafiltration membrane modified by TiO_2 sol

采用溶胶-凝胶法制备TiO2溶胶,优化了溶胶制备条件。采用相转化法制备了一系列TiO2含量的PPESK/TiO2有机-无机杂化超滤膜,并通过SEM,水接触角和超滤实验考察了TiO2含量对膜结构和性能的影响.结果表明,冰乙酸、去离子水和NMP用量分别为2,2,20mL时,溶胶胶凝时间为42.5h,利于杂化膜的制备.TiO2溶胶的加入,抑制了亚层指状孔的发展,利于海绵状孔的生成.膜的孔隙率、亲水性和抗污染性得到了明显改善.当TiO2质量分数为0.4%时,膜的纯水通量由310L/(m2·h)提高到427L/(m2·h),清洗后,膜通量恢复率为95.2%.但加入过量的TiO2溶胶时,纳米粒子的团聚使得杂化膜的各项性能下降.PPESK/TiO2杂化膜更适于高温凝结水的回用处理,处理效率高.

A TiO2 sol was prepared using sol-gel method and the reaction conditions were optimized. PPESK/TiO2organic-inorganic hybrid ultrafiltration （UF） membranes with different TiO2 concentrations were prepared by phase inversion method. The effects of TiO2 concentration on the morphologies and properties of the membances were investigated through SEM, water contact angle and UF experiments. The results showed that the optimal reaction conditions for TiO2 sol preparation were acetic acid 2 mL, de- ionized water 2 mL and NMP 20 mE. Under the conditions, the gelation time was 42. 5 h. The penetrated finger-like pore structure in sublayer was suppressed, and sponge-like structure began to be developed. The porosity, hydrophilicity and anl^i-fouling properties have been obviously improved. When Ti（）2 concen- tration was 0.4%, the pure water flux was increased from 310 L/（m2·h）to 427 L/（m2· h）, and the flux recovery rate of membrane was 95. 2%. However, excess TiO2 concentration caused the aggregation of nanoparticles resulting in the performance decline. Compared with PPESK membrane, the PPESK/TiO2 organic-inorganic hybrid UF membrane was better for the purification of high temperature condensed wa- ter, showing higher removal efficiency.