Liquid-based porous membranes

Porous membranes have a long history of research and applications, and their operations have been consolidated for a wide range of uses in the fields of chemical separation, water treatment, food production, catalysis, and energy storage and conversion. Regardless of their significance in the above areas, they still suffer from compromise that arise due to achieving a balance between the selectivity and permeability, fouling issues, and lack of adaptability to meet versatile and aggressive environments. Liquid-based porous membranes have come to the fore as a new alternative to avert these challenges with significant advantages in diffusive, dynamic, antifouling, omniphobic, self-healing, and adaptive properties. Although rapidly progressing, there is a still lack of a comprehensive review that specifically addresses these members of the membrane family, and more importantly, the confusions occurring among myriad liquid-based porous membranes that have impeded their applications in potential uses. With this goal, this tutorial review will give a new unifying view on the state-of-the-art progress of liquid-based porous membranes, including the historical timeline, interfacial behavior, materials design, materials chemistry, mass transport mechanism, fluid behavior, and emerging applications. Anatomizing the basic aspects such as chemical compatibility and mutual interplays between the porous matrix and the infused functional liquid, and the varied transport mechanisms, we hope to dissolve the complexities of liquid-based porous membranes for more audience. Emergent applications such as gas separation, extraction, smart gating systems, multiphase separation, and chemical detection are also touched upon, inspiring frontier researches in interfacial chemistry, material chemistry, fluid mechanics, membrane science, chemical engineering, etc.