Nanofibrous metal-organic framework composite membrane for selective efficient oil/water emulsion separation

Among the various environmental problems, that of water pollution is undoubtedly one of the most severe that mankind faces; this global challenge requires efficient separation of surfactant-stabilized oil/water emulsions to be solved. Here, a separation membrane with unique wettability is prepared by integrating polyacrylonitrile nanofibers with nanocrystalline zeolite imidazole framework (ZIF-8). The membrane shows prewetting-induced superoleophobicity under water and superhydrophobicity under oil. Surfactant-stabilized oil/water emulsions are effectively separated by the hierarchically nanostructured composite membrane. The hybrid membrane displays a high oil contact angle under water (159 degrees) and high water contact angle under oil (155 degrees), resulting in fast separation dynamics and high separation efficiency. This membrane represents a new approach to exploit multifunctional materials for water remediation.