Emulsion-Templated, Magnetic, Hydrophilic-Oleophobic Composites for Controlled Water Removal

Emulsion-templated, hydrophilic-oleophobic porous materials are promising for the removal of a small amount of water from oil-water mixtures, but the maneuver and complete collection of these porous materials are challenging. Herein, we report the fabrication of magnetic, hydrophilic-oleophobic polyHIPE composites from reactive Fe₃O₄ nanoparticle-stabilized high internal phase emulsions through simultaneous bulk polymerization of water-soluble monomers and interface-catalyzed polycondensation of 1H,1H,2H,2H-perfluorooctyltriethoxysilane. The resulting composites were hydrophilic-oleophobic, with water droplets rapidly absorbed (within 20 s), and exhibited designable magnetic responsiveness. The hydrophilicity-oleophobicity enabled water to be removed through selective absorption from oil-water mixtures (including surfactant-stabilized water-in-oil emulsions), with a high separation rate over 99%. The magnetic-responsiveness enabled both the dry and the swollen composites to be maneuvered in a remote and contactless manner and to be fully collected. Therefore, the magnetic, hydrophilic-oleophobic polyHIPE composites are excellent candidates for the removal of water from water-oil mixtures with complete collection.