Fabrication and applications of ionic covalent organic framework membranes

Abstract

Ionic covalent organic frameworks (iCOFs) are a type of highly crystalline organic porous materials that introduce ionic groups based on COFs. Owing to their ionic functional groups, iCOFs are endowed with stronger ion exchange and adsorption capabilities, excellent ion transport properties, and abundant catalytic active sites, while still inheriting the long-range ordered pore structure, high specific surface area, structural designability, tunable pore size, and high stability of COFs. Due to their unique properties, iCOFs have been successfully integrated with membrane technology, which better preserves the inherent structural advantages of iCOF materials while enabling continuous manufacturing processes and straightforward device integration, unlocking wide applications in fields such as ion conduction, membrane separation, biomedical applications, sensing, etc. To date, few reviews have comprehensively explored the design and application of ionic covalent organic framework membranes (iCOFMs), and a comprehensive review is presented here on the classification characteristics, membrane preparation methods, and application prospects of iCOFMs. Finally, the potential of iCOFMs is discussed from sustainable development perspectives, acknowledging both challenges and opportunities, with promising implications for advancing membrane technology, iCOFs research, and industrial implementation.