高通量聚苯并咪唑纳滤膜的结构调控及性能

High Flux Polybenzimidazole Solvent Resistant Nanofiltration Membranes: Morphology Control and Performance

聚苯并咪唑(PBI)是一种类杂环聚合物,具有独特的耐高温性、化学稳定性和机械稳定性,因而被广泛用作膜材料.PBI膜具有很高的选择性,在耐溶剂纳滤领域具有较好的应用前景.本文在PBI铸膜液中引入亲水性添加剂聚乙烯吡咯烷酮(PVP-K30),通过调节PVP的含量来改变成膜过程中的动力学过程,继而对PBI膜的结构进行进一步调控,从而改善其渗透通量.研究表明,随着制膜液中PVP含量的增加,通量不断升高,对染料的截留保持稳定.当PVP质量分数为15%时,PBI膜对亚甲基蓝的截留率达到99.18%,表现出优异的分离性能.

A kind of heterocyclic polymer polybenzimidazole（ PBI） membranes are very promising for solvent resistant nanofiltration due to their excellent mechanical stability,thermal stability and chemical stability.Even though they showed high selectivity,however,the permeance is relatively low. In this study,we aim to enhance the permeance of PBI membranes while keep their selectivity. PBI membrane with different microstructures were prepared by introducing polyvinylpyrrolidone（ PVP） in cast solution. The results showed that with increasing content of PVP,the flux of membrane increases,while,the rejection on dyes keeps constant.When the mass ratio of PVP is 15%,the PBI showed retention of 99. 18% on methylene blue,showing very good selectivity.