不同聚合物分子量对相转化法制备PVDF微滤膜性能的影响

EFFECTS OF POLYMER MOLECULAR WEIGHT ON PVDF MICROFILTRATION MEMBRANE PERFORMANCE BY IMMERSION PRECIPITATION PHASE INVERSION

研究了不同聚合物分子量对浸没沉淀相转化法制备聚偏氟乙烯(PVDF)微滤膜的形态结构、成膜厚度、过滤性能、亲水性、孔隙率、临界通量以及污染性能的影响。试验结果表明,随聚合物分子量的增加,铸膜液黏度越大,越利于膜亚层形成指状连通结构,孔隙率逐渐增大,但成膜厚度及纯水通量逐渐降低。聚合物分子量在一定程度上会影响膜亲水性及膜抗污染性能,即在一定范围内膜的亲水性能及抗污染性能会随聚合物分子量呈正相关性,但超出一定范围则呈负相关性,而临界通量值则随分子量的提高呈现出略微减少的趋势,但相差不大。

In this study, the poly （vinylidene） fluoride （PVDF）-based microfiltration membrane was prepared via immersion-precipitation phase inversion methods. The effects of the polymer molecular weight on the membrane morphological structure, membrane thickness, permeability, hydrophily, porosity, and fouling performance were systematically investigated. The results showed that with the increase of polymer molecular weight, the casting membrane viscosity increased and it was also apt to form the connecting finger-like sub-layer, thus increasing the porosity, while the membrane thickness and pure water flux declined. The membrane hydrophilic and membrane fouling performance was affected by the polymer molecular weight in some extent, i.e. the hydrophilic properties and antifouling performance is positively correlated with the molecular weight of the polymer in a certain range, but beyond the certain range is negatively correlated, while the critical flux showed a slightly decreasing trend with the increase of molecular weight, but the variations isn＇t obvious.