A Novel Sepiolite-based Superhydrophilic/Superoleophobic Coating and Its Application in Oil-Water Separation

The separation of oil-water mixtures has attracted widespread attention for addressing increased oil spillage and oil-polluted water. In this study, a novel and low-cost oil-water separation coating material composed of epoxy (EP) and modified sepiolite (SEP) by poly (diallyldimethylammonium chloride) (PDDA) and sodium perfluorooctanoate (SPFO) was fabricated. The as-prepared coating showed excellent superhydrophilic/superoleophobic properties, determined by its micro/nano rough microstructure, hydrophilic groups of PDDA, and oleophobic groups of SPFO, and it is not damaged by friction even after being wetted by water, which was mainly ascribed to EP with good adhesiveness. More importantly, the surface of stainless-steel mesh sprayed with SEP@PDDA-PFO/EP coating became superhydrophilic/superoleophobic, and showed excellent oil-water separation efficiency, which can avoid the deficits of traditional separation materials easily being polluted and difficult to recycle. This research could provide a novel modification method of SEP and promote its application in oil-water separation.