凝胶成份对PVDF/PVP中空纤维超滤膜结构与性能的影响

EFFECT OF COAGULATION INGREDIENTS ON MICROSTRUCTURE AND PERFORMANCE OF PVDF/PVA BLEND HOLLOW FIBER MEMBRANES

采用干-湿相转化法制备PVDF/PVP共混中空纤维超滤膜,通过改变内外凝胶浴组成控制膜的结构和性能,使用扫描电镜对不同凝胶条件下膜的微观形貌和结构进行了表征,以纯水通量和BSA截留率评价膜性能。结果表明,芯液中溶剂质量分数由10%升高至50%会使膜孔收缩,膜通量下降;芯液中甘油质量分数由10%升至30%后能使膜形成大孔结构,使通量增大。凝胶浴中溶剂质量分数高于40%,会使聚合物溶解,但加入质量分数1%的醋酸能降低高浓度溶剂的溶解作用,使通量升高。

In this study, the researchers prepared PVDF/PVP blending hollow fiber membrane by dry - wet phase catalysis method, and controlled membrane microstructure and filtration properties by changing the composition of inside and outside coagulation bath. Observing membrane micromor-phologies and structure by using the scanning electron microscopy （SEM） under the different conditions of coagulation, and evaluated the membrane performance by water flux and BSA interception rate. The results showed that when the solvents concentration of core fluid increased from 10% to 50% the film hole contracted and the film flux declined; concentration of the glycerol in core fluid rise by 10% to 30% can make membrane formation big pore structure and make the flux increased. Solvent concentrations of gel bath higher than 40%, can make polymer solute, but add 1% of acetic acid can inhibit the dissolution of the high concentration solution effect, make the flux increase, which can get their best spinning parameters.