扩散致相转化法制备结晶性聚合物多孔膜

Formation of Porous Membranes from Crystalline Polymersvia Diffusion-Induced Phase Inversion

介绍了扩散致相转化法制备结晶性聚合物多孔膜的研究现状。其三元等温成膜体系的相图包含液液分相和固液分相两种相分离方式,是理解成膜过程的重要工具,总结了成膜机理和膜的结构形貌:单纯S L相分离生成粒子状对称膜结构;单纯L L相分离生成蜂窝状非对称膜结构;两种相分离方式竞争发生将生成多样的混合膜结构。铸膜液浓度、非溶剂种类、铸膜溶剂组成、凝胶浴组成、制膜温度是影响膜结构形貌的主要因素。

The paper describes recent research advances related to the porous membranes from crystalline polymers via diffusion-induced phase inversion. The isothermal phase diagram for ternary polymer systems, exhibiting both a solid-liquid and a liquid-liquid demixng gap, is an important tool to understand membrane formation. The solid-liquid demixing process gives rise to the uniform particulate morphology. the liquid-liquid demixing process contributes to the asymmetric spongy structures. As the result of competition between solid-liquid demixing and liquid-liquid demixing, the membrane exhibits a structure containing features from both types of phase separations. Therefore, a wide variety of membrane morphologies can be synthesized. In the end, factors controlling membrane morphologies, such as polymer concentration of the casting solution, nonsolvent type, composition of the casting solution, composition of the coagulation bath, and operation temperature, are discussed in detail.