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 (H-1 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 153A degrees and a sliding angle of 4.5A degrees, 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 145A degrees, 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.