Superhydrophobic–superoleophilic stainless steel meshes by spray-coating of a POSS hybrid acrylic polymer for oil–water separation

Superhydrophobic–superoleophilic meshes with hierarchical structures were fabricated by spraying a POSS hybrid acrylic polymer on stainless steel mesh for oil–water separation in this paper. Fourier transform infrared spectroscopy, nuclear magnetic resonance (1H NMR), and thermogravimetric analyses were used to verify the chemical composition and thermostability of the POSS hybrid acrylic polymer, which was synthesized via a free radical solution polymerization. The obtained mesh was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and optical contact angle meter to confirm the morphology, composition, and wettability of the film surface. The coated mesh, with a static water contact angle of 153° and a sliding angle of 4.5°, was applied to separate a series of oil–water mixtures, such as n-hexane, isooctane, petroleum ether, kerosene, and vegetable oil, with separation efficiency nearly 99%. In addition, the coated mesh still kept separation efficiency approximately 99% even after 25 separation cycles for n-hexane/water mixture. After 20 abrasion cycles, the water contact angle of the mesh remained 145°, and separation efficiency for n-hexane/water mixture is approximately 99%, indicating the coated mesh possessed good mechanical stability. The as-prepared mesh will be a promising material in oil–water separation, due to the simple, low-cost, and easily scalable fabrication method and the excellent separation performance in radical oil–water separation.