聚偏氟乙烯膜微孔的形成机理  

Pore forming mechanism of phase inversion membrane

作　　者：武利顺[1] 孙俊芬[2] 王庆瑞[2] 

机构地区：[1]山东省菏泽学院化学化工系,菏泽274015 [2]东华大学材料学院,上海200051

出　　处：《膜科学与技术》2007年第5期13-17,21,共6页Membrane Science and Technology

摘　　要：通过改变聚偏氟乙烯膜的制膜条件,采用扫描电镜观察了膜孔的不同结构.观察了膜的皮层结构、海绵状孔、指状孔以及指状孔壁的结构.根据实验解释了膜的皮层和支撑层孔的形成机理.膜的皮层按旋节线分相机理形成,主要由热力学因素决定.溶剂和沉淀剂通过皮层扩散交换速率的快慢决定膜的支撑层的孔结构,膜的支撑层的孔结构按成核生长机理进行,这里动力学因素起到主要作用.溶剂和沉淀剂通过皮层的扩散速率快,膜的支撑层形成指状孔结构;扩散速率慢,膜的支撑层形成海绵状孔结构;扩散速率适中,膜的断面上部形成指状孔结构,下部形成海绵状孔结构.Different pore structures were obtained via changing membrane formation conditions and observed under SEM. The structure of sponge - like pores, finger - like pores and the wall of finger- like pores were investigated. Formation mechanism of the skin layer and the support layers were explained based on the experimental phenomena. The formation of the skin layer agrees with the spinodal decomposition （SD） mechanism, and the thermodynamic factor plays the leading role in this process. The structure of the support layer is determined by the diffusion rates of coagulant and solvent that cross the skin layer. The formation of the support layer agrees with the nucleation and growth （NG） mechanism, and the kinetic factor plays the leading role in this process. Finger - like structure will be formed if the diffusion rates across the skin layer are high, and sponge - like structure will be formed if the diffusion rates are low. Finger-like pores will be formed in the upper part of the support layer, and sponge - like pores will be formed in the lower part when the diffusion rates of coagulant and solvent across the skin layer are in moderate level.

关 键 词：相转化 膜 机理 稀相核 

分 类 号：TQ320.721[化学工程—合成树脂塑料工业]