Polymer-infiltrated approach to produce robust and easy repairable superhydrophobic mesh for high-efficiency oil/water separation

A superhydrophobic and superoleophilic polymer-infiltrated nanoparticle film-coated stainless-steel mesh (PINF-SSM) was prepared with a novel and facile nature-inspired approach. The approach involves the use of low-cost raw materials and simple spray coating of hydrophobic silica nanoparticles onto stainless-steel mesh (SSM) surface. With acrylic resin pre-coating layer on both surfaces, it is conveniently transformed into an integrated polymer-infiltrated nanoparticle film on SSM after annealing above the resin's glass transition temperature. The obtained PINF-SSM shows robust superhydrophobicity after multiple cycles rubbing with sandpaper, long-term UV irradiation, long-term storage, and exposure to strong acidic, alkaline, and saline solutions. The as-prepared PINF-SSM was successfully used to separate various oil/water mixtures with high-efficiency for at least 50 cycles and collect oil slick on water surface efficiently. Sequential coating thermoplastic acrylic resin and hydrophobic silica nanoparticles on the surface of SSM allow for extended storage time of the coating materials, easy resin processing with high silica content, quick repairing, and easy recovery of the superhydrophobic surface, making it suitable in various oil/water separation practices.