Selective Wettability and Pore-Size Exclusion Synergistic Membrane for Efficient Oil–Water Separation

Offshore oil spills and oily wastewater cause severe water pollution. Membrane separation offers a promising solution for efficient oil-water separation; however, conventional membranes often exhibit poor fouling resistance and face a trade-off between flux and separation efficiency due to mismatched pore sizes. To overcome these challenges, we developed a hydrolyzed polyacrylonitrile by tetraethyl orthosilicate modification (HPANT) nanofibrous membrane based on the synergistic mechanism of selective wettability and pore-size exclusion. And it achieves superhydrophilicity and underwater superoleophobicity, with the pore size regulated to ∼20 nm. This design achieves excellent fouling resistance and separation efficiencies of 98.29% for immiscible mixtures and 97.80% for surfactant-stabilized emulsions, with high fluxes of 6,941.5 L·L·m^-2·h^-1·bar^-1 and 8,379.6 L·m^-2·h^-1·bar^-1, respectively. Multiscale simulations (DFT, MD, FEM) further clarify the dual mechanism: the stable hydration layer resisting oil adhesion and tailored nanopores providing a physical barrier. This strategy provides guidance for the development of oil-water separation membranes.