Separation Principles and Strategies for an Oil–Water Separation Membrane with Special Wettability

Although numerous reviews have discussed the research progress in “filtration-type” oil–water membrane separation with special wettability, they predominantly focus on the types of membrane separation and preparation methods, without providing an in-depth analysis of the separation principles and strategies. This paper is different from the previous reviews focusing on the types and preparation methods of membrane separation, mainly as regards membrane surface adsorption, liquid through the pores, and liquid extraction from the pores of the three key nodes in order to analyze the impact of membrane block wettability on the oil–water separation effect of the independent influence. Accordingly, we summed up the membrane separation principle and design strategy to guide modular wettability design during membrane fabrication, thereby enhancing membrane wettability. The modular wettability design approach can provide guidance during the membrane development phase, offering potential solutions to extend membrane lifespan and address issues of surface fouling and pore clogging while enhancing mass transfer efficiency during operation.