以H2O/DMAc为共溶剂,相转化法制备了PVDF/PVP平板超滤膜,考察了非溶剂水添加量对相分离进程、膜结构参数、膜分离性能的影响规律,观察了膜的微观形貌。结果显示,随着体系中含水量由1%~5%变化时,相转化成膜固化时间缩短,膜表面孔数增多,支撑层逐渐疏松,膜断面大孔结构变化丰富,呈现不规律变化,但膜平均孔径相对稳定。含水量由0%变化至5%,膜纯水通量从850L/(m2.h)上升到1250L/(m2·h),BSA截留率基本保持在85%以上,在3%时最高,5%时有所下降。
Flat sheet ultrafiltration membranes were prepared from the solution of PVDF/PVP by phase inversion method, water and dimethyl acetylamide(DMAc) were used as blend solvents. The influences of non-solvent water content on phase separation behaviors, membrane structure and separation properties were researched. The microcosmic morphology and structure of the resulting membrane were observed. Results showed that with the increase of water content from 1% to 5%, the solidification time of phase-inversion into film was shorten, the pore number of membrane surface increased, the structure of support layer gradually became loose, cross-sectional structure changed richly and irregularly, but the average pore radius were relatively stable. As water content changed from 0 to 5%, the pure water flux increased from 850 L/(m2.h) to 1 250 L/(m2 .h); the BSA rejection basically remained above 85%, when in 3% arrived at maximum and decreased at 5%.