芯液组成对PVC-PFSA中空纤维共混膜性能的影响

Effect of bore fluid composition on the performance of PVC-PFSA hollow fiber blend membrane

以聚氯乙烯(PVC)为膜材料,N,N-二甲基乙酰胺(DMAc)为溶剂,全氟磺酸(PFSA)为添加剂,采用湿法制备了性能较好的PVC中空纤维共混超滤膜.研究了芯液组成对PVC-PFSA中空纤维膜性能的影响,研究结果表明:纯水通量随全氟磺酸浓度的增加而增加,可达1530 L/(m2.h.MPa).通过调节芯液中DMAc的含量,可以有效调控PVC-PFSA中空纤维膜的内表面和断面结构.PFSA含量2.5%,随着芯液中DMAc含量的增加,PVC-PFSA中空纤维膜断面的双排指状孔逐渐向单排指状孔过渡,孔隙率增大.当DMAc含量增加到95%时,在PVC-PFSA中空纤维膜的内表面可以形成明显的多孔状结构,膜通量大幅度提高,可达1 180 L/(m2.h.MPa).

PVC-PFSA hollow fiber blend ultrafiltration membrane were prepared using polyvinyl chloride （PVC） as a membrane material, N, N-dimethylacetamide （DMAe） as solvent, and perfluorinated sulfonic acid （PFSA） as additive. The effects of bore fluid composition on the performance of PVC-PFSA hollow fiber composite membrane were investigated. The results show that pure water permeation flux increase with the PFSA concentration and reach to 1 530 L/（m2 · h · MPa）. The microstructure of PVC PFSA hollow fiber membrane could be effectively controlled by adiusting the content of DMAc in the bore solution. With the increase of DMAc content, double finger-shaped voids on the cross-section of PVC-PFSA hollow fiber membrane gradually transition to a single row of finger void, porosity increases at the same time. Porous sponge-like structure appeared on the inner surface when the DMAc content increased to 95%, and the membrane flux increased to 1 180 L/（m2· h · MPa）.