分子量对聚丙烯腈超滤膜的性能影响

Influence of molecular weight on performance of polyacrylonitrile ultrafiltration membrane

为研究聚丙烯腈(PAN)分子量对PAN超滤膜结构和性能的影响,使用相转化法制备了4种不同黏均分子量(M_(η)≈2.2×10^(5)g/mol、6×10^(5)g/mol、7×10^(5)g/mol、8×10^(5)g/mol)的PAN膜。通过向溶液中加入常用添加剂(PEG⁃4000或SiO_(2))的方法调整PAN超滤膜的结构和性能。结果表明,随着PAN分子量的增加,PAN膜的水通量和截留通量都会降低,指状孔减小,亲水性变差;在加入添加剂后,膜的指状孔扩张,亲水性变好。高分子量的PAN膜水通量从初始的100 L/(h·bar)提升到3000 L/(h·bar),过滤后的油水混合物的浓度均在5 mg/L左右。

This article reported an investigation on the structure and performance of the polyacrylonitrile(PAN)ultrafiltration membranes prepared by a phase⁃transformation method using four types of PAN with different viscosity average⁃molecular weights(M_(η)≈2.2×10^(5)g/mol,6×10^(5)g/mol,7×10^(5)g/mol,8×10^(5)g/mol).PEG⁃4000 or SiO_(2)as a common additive was added to the solution to adjust the microstructure and performance of the ultrafiltration membranes.The results indicated that the water flux and retention flux of the ultrafiltration membranes decreased with an increase in the molecular weight of PAN.However,there is a reduction in the finger shaped⁃hole and hydrophilicity with an increase in the molecular weight of PAN.In contrast,the finger shaped⁃hole and hydrophilicity were improved with the addition of the additives.Meanwhile,the water flux of the PAN ultrafiltration membrane with a high molecular weight increased from 100 to 3000 L/(h·bar)after the addition of the additives,and the average concentration of the filtered oil⁃water mixture was 5 mg/L.