Perspectives for chitosan-based membranes in CO2/N2 separation : Structure-property relationship

Extensive research has been conducted on a variety of processes for abating the increasing CO<inf>2</inf> emissions which have been causing adverse effects on the environment. Among these, gas separation membranes have the potential to overcome a number of limitations of existing technologies by reducing the cost of operations and providing an efficient, compact module which can be employed for separating CO<inf>2</inf> from natural gas and post-combustion flue gas streams. Recently, chitosan and its derivatives have proven their ability to form CO<inf>2</inf>-selective facilitated transport membranes through the utilization of the amino group fixed site carriers present in the polymer. Later, the performance of chitosan membrane can be substantially improved by carrier enrichment. This review aims to cover the structure-property relations of chitosan and its film-forming derivatives, with a brief discussion of the advantages and challenges in using these polymers. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.