Abstract:

Nanofiltration (NF) membranes have attracted more and more attention due to their low operation pressure, high flux, separation selectivity and low operating costs. At present, NF membranes have played an important role in the desalination of brackish water, sewage treatment and desalination. As a commonly used method for the preparation of polyamide NF membranes, interfacial polymerization can effectively adjust the microstructure of the NF membranes by adjusting the polymerization process, which further has a significant influence on its separation performance. This article started with the structure of the composite NF membrane, and made a comparative summary of the popular modification methods to improve the performance of NF membranes, including the optimization of the separation selection layer, the construction of the intermediate layer and the adjustment of the support structure. During the course of the interfacial polymerization, the influence of reactive monomers, types of additives and preparation conditions, etc. on the separation layer structure and separation performance were discussed. The effects of physical and chemical properties such as the pore size, porosity and hydrophobicity of the supporting membrane on the performance of the composite membrane and the advantages and disadvantages of different types of intermediate layers were also analyzed. Finally, the current problems that need to be solved in the industry were summarized and the future development trend of NF membranes had been prospected.

Key words: nanofiltration membrane, interfacial polymerization, membrane structure, interlayer, separation performance

摘要：

纳滤膜因操作压力低、通量高、具有分离选择性以及运行成本较低等优势引起越来越多的关注，目前已在苦咸水脱盐、污水治理和海水淡化等领域发挥着重要作用。界面聚合作为常见的制备聚酰胺纳滤膜的方法，其聚合反应进程的调控可以有效地调节纳滤膜的微观结构，进而对其分离性能产生重要影响。本文从复合纳滤膜的结构入手，总结了当前常用的提升纳滤膜性能的改性方法，包括优化分离选择层、构建中间层、调整底膜结构三个方面，讨论了界面聚合过程反应单体、添加剂种类、制备条件等对分离层结构和分离性能的影响，并分析了底膜的孔径、孔隙率、亲疏水性等理化性质对复合膜性能的影响以及不同类型中间层的优缺点。在此基础上，总结了当前业界内亟待解决的问题，并对纳滤膜的未来发展趋势进行了展望。

关键词: 纳滤膜, 界面聚合, 膜结构, 中间层, 分离性能