Amino-functionalized mesoporous PVA/SiO2 hybrids coated membrane for simultaneous removal of oils and water-soluble contaminants from emulsion

Abstract A novel approach for simultaneously removing oil droplets and water-soluble contaminants from stabilized oil/water emulsion has been developed. Herein, the polyvinyl alcohol (PVA)/SiO2 hybrid coatings were fabricated via “one-step” hydrolysis and co-condensation, which possesses unique mesoporous structures (pore diameter ≈ 9.31 nm) and abundant amino groups. Hydrophobic polyvinylidene fluoride (PVDF) membranes adhered firmly by the hybrid coatings, are endowed with superhydrophilicity/underwater superoleophobicity, excellent antifouling performance, ultrahigh water flux (6343.2 L m−2 h−1 bar−1), highly efficient oil-in-water emulsion separating capability (filtrate flux = 544.26 L m−2 h−1 bar−1) and gravity-driven separation capability. Moreover, copper ion (Cu2+) and methyl blue (MB) can be effectively absorbed from water phase, with considerable adsorption capacities (Qc) of 52.8 mg/g and 41.88 mg/g, respectively. After 5 reusing cycles, the relative removal efficiencies (RE) are still higher than 86.89% and 99.76%, respectively. Moreover, with the outstanding reusability and considerable chemical durability, the as-prepared membranes are promising candidate in practical application for wastewater treatment, bridging the gap between contaminants adsorption and oil/water separation.