关键词: 支撑基底, 界面聚合, 聚酰胺复合膜, 膜结构优化

Abstract:

Polyamide composite membrane fabricated by interfacial polymerization has been widely used in wastewater treatment, seawater desalination and other fields. However, the structure of polyamide composite membrane plays a key role in its application. Most of the previous studies focused on the selective layer, while there are relatively few studies concentrated on the microporous substrate of the composite membrane. The results show that the physicochemical characteristics of microporous substrate exhibit a great influence on the formation of polyamide selective layer and the corresponding properties of the resultant composite membrane. Therefore, this review first introduced the preparation technologies of the substrate, then focused on the different modification methods of the microporous substrate, including the traditional substrate improvement method and the material and structure of the new substrate. Furthermore, the effects of substrate structure on the structure and performance of the pressure-driven membrane (nanofiltration, reverse osmosis) and osmotic pressure-driven membrane (forward osmosis) were discussed. The analyses showed that the microporous substrate with high porosity and good hydrophilicity can effectively regulate the storage and diffusion of the aqueous monomers in the process of interfacial polymerization, which would be beneficial to obtain the polyamide composite membranes with high water permeance and excellent selectivity. Therefore, in the future, it is still necessary to develop more potential microporous substrate materials and construct ideal structures from several aspects such as polymer materials and nano-modification, so as to promote the application and development of the polyamide composite membranes.

Key words: supporting substrate, interfacial polymerization, polyamide composite membrane, improvement of membrane structure