关键词: 纳滤膜, 界面聚合, 膜结构, 中间层, 分离性能

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