Simple preparation of a durable and low-cost load-bearing three-dimensional porous material for emulsion separation

Super-wetting materials are widely used to treat oil–water mixed sewage. However, there are still great challenges in manufacturing strong and durable super-wetting materials for the separation of complex emulsions. A method for the simple preparation of durable, low-cost, superhydrophobic, and superlipophilic 3D materials is reported in this paper. Superhydrophobic metal rubber, MR–C, was successfully prepared by depositing low-cost candle soot on a metal rubber workblank, and then stamping and dipping the soot-coated rubber workblank in a polydimethylsiloxane solution. MR–C effectively separated a variety of water-in-oil emulsions driven by gravity. In addition, because the 3D porous material acted as a protective layer, MR–C could still be used to efficiently separate emulsions even after the sample was subjected to a wear test under 500 N loads. After being immersed in a corrosive environment for a long time, the surface of the material maintained its stable superhydrophobic properties. The stable and efficient separation efficiency and strong mechanical durability ensure the reusability of MR–C in purification, and it shows great potential in oily wastewater treatment applications.