Environmentally friendly kaolin-coated meshes with superhydrophilicity and underwater superoleophobicity for oil/water separation

[Display omitted] •Modified kaolin-coated meshes were prepared via simple immersion method.•The mesh acts well in various oil/organic solvents and water mixture separation.•The prepared mesh can realize efficient water-in-oil emulsion separation.•The as-prepared mesh shows excellent stability in corrosive condition. Due to the increase in oil spill accidents and discharge of oily wastewater, it is urgent to develop functional materials to separate oil from oil/water mixtures. In this work, the kaolin-coated meshes were fabricated by a facile coating method to construct a micro-hierarchical surface and controllable pore size for the separation of various oil/water mixtures. The obtained meshes exhibits super-hydrophilicity, underwater super-oleophobicity with underwater oil contact angle >150° and outstanding oil/water separation efficiency above 99% and flux up to 190 L m−2 h−1 under gravity force. Moreover, the mesh still maintained high stability and good separation efficiency under corrosive condition and recycling. Furthermore, the mesh can also remove water from the water-in-oil emulsion. Results from this study are meaningful for the development of low-cost, and eco-friendly materials with high efficiency and mechanical robustness for oily wastewater treatment and open a new way for high-increment utilization of kaolin mineral.