聚电解质层层自组装纳滤膜

Nanofiltration Membranes Prepared by Layer-by-Layer Self-Assembly of Polyelectrolyte

层层自组装技术能够方便地对膜的微观结构和组成进行调控,已在制备复合型纳滤膜方面取得了迅速的发展。本文综述了近年来用于聚电解质层层自组装纳滤膜的制备方法、种类以及影响因素。介绍了静态层层交替沉积、压力驱动自组装和电场强化自组装等3种制备方法;归纳了均聚型、共聚型和有机/无机杂化型等3类用于层层自组装纳滤膜的聚电解质的特点;讨论了聚电解质的荷电性、电荷密度和电离程度等因素对其自组装膜分离性能的影响。总结了聚电解质自组装纳滤膜在水处理和有机溶剂中物质的分离等方面的应用。同时,对提高聚电解质自组装纳滤膜的组装效率、分离性能和发展方向提出了设想和建议。

Ultrathin composite nanofiltration（NF）membranes fabricated by layer-by-layer（LbL）assembly technique,which can precisely control structures and compositions,has received a rapid development.In this paper,a review is presented on LbL assembly methods,types of polyelectrolytes and influencing factors of LbL assembly NF membranes in recent years.Three different approaches for LbL assembly are mainly introduced,including the conventional electrostatic deposition method,the pressure-driven LbL assembly and the electric field enhanced LbL assembly.The types of the self-assembled polyelectrolyte materials,which can be classified into homopolymer,copolymer,and organic-inorganic hybrid polyelectrolytes are carried out.Separation performances of NF membrane influenced by various factors,such as the charge character,the charge density and the ionization degree of the polyelectrolyte are discussed.The applications of LbL assembly NF membrane for water-treatment and substances separation from organic solvent are summarized.At the same time,some propose of speeding up the assembly process,improving the performance and development orientation of NF membranes are presented.