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

摘要：

通过界面聚合法获得的聚酰胺复合膜在污废水处理、海水淡化等领域得到广泛应用，然而聚酰胺复合膜的结构对其应用起到关键作用，以往研究多数聚焦在分离层，而对复合膜微孔支撑基底的研究相对较少。研究表明，微孔基底的物化特征对于聚酰胺分离层结构的形成及复合膜性能起着至关重要的影响作用。为此，本文从支撑基底的制备工艺出发，围绕微孔基底的不同改性手段，介绍了传统基底改进方法和新型基底的材料与结构，并探讨了基底结构对压力驱动膜（纳滤、反渗透）与渗透压驱动膜（正渗透）分离层结构与性能的影响。分析表明，具有高孔隙率、亲水性好的微孔基底可有效调控界面聚合过程中单体的储存与扩散，有利于获得高渗透和高选择性能的聚酰胺复合膜。因此，未来仍需从聚合物材料及纳米改性等几个方面，发展更具潜力的微孔基底材料与结构，以推动聚酰胺复合膜的应用发展。

关键词: 支撑基底, 界面聚合, 聚酰胺复合膜, 膜结构优化