论文部分内容阅读
在相转换法制备非对称微孔膜过程中,凝胶化条件是重要的孔结构控制因素之一。本文以乙醇水溶液和甲醇水溶液为沉淀剂,讨论了沉淀剂的溶解度参数对聚偏氟乙烯膜孔结构的影响,利用扫描电镜观察了所得膜的形态结构,发现当沉淀剂的溶解度参数从小到大变化时,膜的形态从海绵状结构逐渐过渡到指状结构;在两种结构各半的转变点处,孔隙率和平均孔径均处于最小值。不同铸膜液体系具有相似的成膜规律,但“转变点”的位置可能有所不同。实验结果表明,沉淀剂的溶解度参数可以作为定量或半定量描述成膜规律的重要物理参数之一。
In the preparation of asymmetric microporous membranes by phase inversion, gelation conditions are one of the most important pore structure control factors. In this paper, ethanol aqueous solution and methanol aqueous solution were used as precipitants to discuss the effect of the solubility parameter of precipitant on the pore structure of polyvinylidene fluoride (PVDF) membranes. The morphology of the membrane was observed by scanning electron microscopy. The results showed that when the solubility parameter of precipitant was from small to large The morphology of the membrane gradually changed from sponge-like structure to finger-like structure. At the transition point of the two halves of the structure, the porosity and average pore diameter were both at the minimum. Different casting fluid system has a similar rule of film formation, but the location of the “transition point” may be different. The experimental results show that the solubility parameter of the precipitant can be used as one of the important physical parameters for quantitative or semi-quantitative description of the film formation law.