Cyclodextrin membranes prepared by interfacial polymerization for separation

Cyclodextrin has a unique hydrophobic cavity and hydrophilic outer surface. The membrane formed by cyclodextrin polymerization has high permeability to both polar and non-polar solvents. Through interfacial polymerization, cyclodextrins can be arranged in an orderly manner to form a membrane with well-defined sub-nanometre channels. In 2022, the sub-nanometre channels in cyclodextrin membranes were visualized, providing ample confidence for precise channel design and precise molecular sieving. This article reviews the development of cyclodextrin membranes in the past decade from the aspects of interfacial polymerization, classification, performance improvement, and application. The focus was on introducing methods to improve the selectivity, permeability, chemical stability, anti-fouling, and chlorine resistance of cyclodextrin membranes. Finally, some issues and development prospects in the application of cyclodextrin membranes were discussed. We hope this review can provide guidance for the development of high-performance membranes to meet the urgent need for sustainable separation.