热致相分离法制备聚偏氟乙烯中空纤维微孔膜

Preparation of microporous poly(vinylidene fluoride)hollow fiber membranes via thermally induced phase separation

从聚偏氟乙烯(PVDF)/三乙酸甘油酯(GTA)/癸二酸二丁酯(DBS)体系中,采用热致相分离法,制备聚偏氟乙烯(PVDF)中空纤维微孔膜.研究了铸膜液的组成:混合稀释剂中GTA的浓度、PVDF浓度,和纺丝条件:空气隙距离、水浴温度、挤出温度,对PVDF中空纤维膜的结构和性能的影响.结果表明:随着混合稀释剂中的GTA质量分数从30%增加至50%,膜的断面由双连续结构转变为变形的球晶与双连续共存的结构.低的PVDF浓度、长的空气隙距离、高的水浴温度,均利于膜水通量的提高,但膜对牛血清蛋白的截留率下降,拉伸强度减小.挤出温度升高,膜的水通量先增加后减小,截留率和拉伸先减小后增加.

Poly（vinylidene fluoride） （PVDF） hollow fiber microporous membranes were prepared using a mixed diluent of glyceryl triacetate （GTA） and dibutyl sebacate （DBS） via thermally induced phase separation （TIPS）. A systematic study was carried out to investigate effects of varying the components of the casting membrane solution（GTA） concentration in mixed diluent, PVI）F concentration in the casting membrane solution）, and the spinning parameters （water bath temperature, air-gap distance, extruding temperature） on the structure and performance of the PVDF hollow fiber membranes. It was found that the cross section of the membrane changed from an interconnected structure into a combination of spherulitic and interconnected structures as the GTA mass concentration in the mixed diluent increased from 30% to 50~. The water flux of the PVDF hollow fiber membrane increased as PVDF mass concentration in the casting membrane solution decreased, the air-gap distance increased, or the water bath temperature increased. However, the corresponding solution rejection and the tensile strength of the PVDF hollow fiber membrane decreased. As the extruding temperature was increased, the water flux of the PVDF hollow fiber membrane increased initially and then decreased, while the solution rejection and the tensile strength of PVDF hollow fiber membrane decreased initially and then increased.