聚芳硫醚砜纳滤膜的制备及耐溶剂特性表征

Preparation of flat sheet nanofiltration membranes based on polyarylenesulfidesulfone and a study of their seperation ability

以聚芳硫醚砜(PASS)为材料,采用浸没沉淀相转化法制备出平板纳滤膜,研究了制膜过程中工艺参数如聚合物浓度等对膜结构与分离性能的影响,确定最佳制膜条件为:聚合物质量分数22%,刮膜温度80℃,滞空时间0 s,凝固浴为纯水。在0.5 MPa压力下,最佳条件下制备膜的纯水通量为50.0 L/(m^2·h),质量分数为0.01%的刚果红水溶液通量为47.6 L/(m^2·h),对刚果红截留率为96.0%。耐溶剂实验结果表明,有机溶剂包括甲苯、二乙醚、甲醇、乙酸乙酯、正己烷和酸碱处理(pH=0~14)对PASS膜通量有较大影响,而对截留率影响不明显,显示出膜具有良好的耐溶剂特性。

Nanofiltration （NF） membranes based on polyarylene sulfide sulfone （PASS） have been prepared by an immersion precipitation method using pure water as the coagulation bath. The effects of varying the preparation parameters, including （1） polymer concentration, （2） preparation temperature, and （3） air exposure time, on the microstructure and separation performance of the resulting PASS membranes, including water flux and rejection of dyes, were investigated in detail. The optimal membrane preparation parameters were found to be： 22% PASS mass fraction, a doping temperature of 80 ℃, and 0 s exposure time. Under these conditions, the obtained PASS membrane exhibited a pure water flux of 50.0 L/（m^2·h） , a water flux of 0.01% of congo red （CR） solution of 47.6 L/（m^2·h） with a 96.0% rejection to CR. The structures of the membranes were characterized by scanning e- lectron microscopy （SEM）. The effects of different organic solvents including toluene, diethyl ether, methanol, ethyl acetate, and n -hexane, as well as sodium hydroxide （1 tool/L） and hydrochloric acid （1 mol/L） solutions on the separation performance with 0. 01% mass fraction of congo red solution were systematically studied. Specific- ally, the PASS membranes were soaked in the above mentioned solvents for 1 day or 7 days, and their separation performance was then evaluated. The results showed that the water fluxes were significantly changed but the rejections to CR were similar. Hence, the PASS membrane had excellent solvent resistance.