Ionic liquids membranes for liquid separation: status and challenges

Ionic liquid-based membranes (ILMs) have garnered significant attention due to the unique coordination properties offered by both ILs and membranes. This makes them a promising area of research with a wide range of potential applications. In recent years, there has been a surge of exciting research activities in the field of ILMs in liquid separation, ranging from fabrication strategies to the development of separation applications. In this review, targeting different types of ILMs, i.e., supported ionic liquid membranes (SILMs), ionic liquid-polymer membranes (ILPMs), poly(ionic liquid) membranes (PILMs), and ionic liquid polymer inclusion membranes (ILPIMs), the preparation strategy, applicability, stability, transport mechanism, and future perspectives are summarized. By providing a comprehensive overview of the different types of ILMs and their applications in liquid separation, this review aims to serve as a valuable resource for researchers and engineers seeking to develop new-type and innovative ILMs for specific separation tasks. It highlights the advantages and limitations of each type of ILMs as well as the various preparation strategies and performance criteria used to evaluate their effectiveness. Ultimately, this information is expected to guide the design and optimization of novel advanced ILMs with enhanced functional properties for real-world applications.