Polybenzimidazole (PBI) and benzimidazole-linked polymer (BILP) membranes

Polybenzimidazoles (PBIs) and benzimidazole-linked polymers (BILPs) have exceptional thermal and chemical stability, and hence, their membranes were developed and used under harsh conditions. In this review, the formation, structures, and properties of these polymers are studied follow by the fabrication of membranes. Applications, such as gas separation, organic solvent nanofiltration, water treatment, pervaporation and proton exchange, are extensively reviewed. The relationship of membrane performance and structure is established, highlighting the importance of processing protocols and post treatments. Future directions are provided on the basis of the conclusions. [Display omitted] •The formation, structures, and properties of PBI and BILP are studied.•Fabrication protocols of membranes are studied.•Membrane applications are reviewed.•The relationship of membrane performance and structure is established.•Conclusions and future directions are provided.