One-step constructing of underwater superoleophobic bed for highly efficient oil-in-water emulsions separation

The efficient separation of emulsified oily wastewater is urgently needed and remains a worldwide challenge. However, the preparation of underwater superoleophobic materials still suffer from complicated process control, special equipment and expensive reagents, which further restricts the large-scale application of such materials. Herein, one-step constructing of underwater superoleophobic beds is introduced for highly efficient gravity-directed separation of various oil-in-water emulsions. Importantly, this study simplifies the fabrication process of underwater superoleophobic materials. It's worth noting that the strategy can achieve the effective separation of a range of oil-in-water emulsions by only requires simple accumulation of hydrophilic materials. More importantly, the underwater superoleophobic sandwich-structured beds still maintain the separation efficiency more than 99.2% after 10 cycles. In addition, this strategy is suitable for a variety of hydrophilic materials, which provides new perspectives for fabrication of novel oil-water emulsion-separating materials.