Flexible cement-sand coated cotton fabrics with superhydrophilic and underwater superoleophobic wettability for the separation of water/oil mixtures and oil-in-water emulsions

Abstract A novel flexible cement-sand coated cotton fabric (CS@CF) with superhydrophilicity and underwater superoleophobicity was prepared by scrape-coating of the paste of cement and sand onto cotton fabric followed by air-drying. The fabrication process avoids chemical reagents, complex reaction, special equipment and complicated procedure, demonstrating a simple, cheap, eco-friendly route to produce superwetting filtration membrane. The as-prepared CS@CF presents high efficiency and recyclability for separating various water/oil mixtures and oil-in-water emulsions. Moreover, the CS@CF could maintain its original wettability in harsh environments, and exhibits remarkable capability for the separation of water/oil mixtures containing hot water, alkali and salt. The simple preparation and excellent behavior could provide the CS@CF with practical application in industrial oily wastewater and oil spill treatments.