通过溶解度参数预测,膜渗透性能检测,及扫描电镜(SEM)对膜形貌观察,考察了聚偏氟乙烯(PVDF)在γ-丁内酯(γ-BL)、磷酸三乙酯(TEP)为混合溶剂,乙二醇(EG)、N,N-二甲基乙酰胺(DMAc)及其混合物为凝固浴时,相转化条件及溶剂配比对PVDF膜在孔隙率、纯水通量、BSA截留率,以及拉伸强度等性能方面的影响行为。结果表明,随混合溶剂中TEP质量分数的增加,凝胶浴中溶剂DMAc质量分数增大,PVDF膜皮层逐渐变薄,PVDF结晶球粒粒径变小,孔隙率增加,拉伸强度下降。当混合溶剂中TEP的质量分数为60%,凝胶浴DMAc含量30%时,膜纯水通量达2100L/(m2.h),BSA截留率仍保持58.7%,具有良好的超滤性能,可作为制备高通量、较高截留PVDF超滤膜的最佳条件。
Combined with solubility parameter, permeability testing and membrane morphology observation by scanning electron microscopy (SEM), the effects of phase transformation condition and the ratio of solvent on the performance of polyvinylidine fluoride (PVDF) membrane in porosity, pure water flux, bovine serum albumin(BSA) solute rejection as well as tensile strength, when using y-butyrolactone (γ-BL), triethyl phosphate (TEP) for mixed solvent and ethylene glycol (EG), N,N-dimethyl acetamide (DMAc) and its mixture for coagulation bath, were investigated. The results showed that with concentration of TEP in the mixed solvent and DMAc in the coagulation bath increased, the top surface evolved from a dense skin to a totally porous morphology, the size of PVDF crystal spherulite became smaller, porosity increased and the strength of membrane decreased. When the concentration of TEP in mixed solvents is 60% and DMAc content of coagulation bath is 30%, the pure water flux amount to 2 100 L/(m2.h) and BSA rejection rate was 58.7%, which was the best formation condition for high-permeance PVDF ultrafiltration membrane.