Stimuli-responsive membranes—mechanisms, materials and future directions

The development of stimuli-responsive membranes, often stated as smart membranes, has garnered increasing attention in recent years owing to their potential in various industrial separation processes and their ability to mimic natural biological systems. Materials suitable for such applications can dynamically adjust their physical and chemical properties, reacting to external stimuli such as temperature, pH, light, or magnetic/electric fields, thereby enabling precise control over membrane microstructure and the dynamic transport of molecules. This review offers an in-depth examination of the chemistry and responsive mechanisms of different stimuli-responsive materials, along with their integration into membrane matrices to optimize performance. Furthermore, it presents a comparative analysis of various types of stimuli-responses, illustrated with pertinent examples. Ultimately, this review highlights the outstanding challenges and future strategies for advancing smart membranes. With ongoing progress in chemistry and materials science, the development of a selective and efficient nanofiltration membrane platform is anticipated to yield significant benefits to advanced separation processes, offering more efficient and integrated technological solutions. (Figure presented.)