The poly(vinyl alcohol-co-ethylene) nanofiber/silica coated composite membranes for oil/water and oil-in-water emulsion separation

In this study, the superhydrophilic and under water oleophobic nanofiber/SiO2 (N/S) coated composite membranes with two kinds substrates of polyamide mesh (PM) and poly(vinyl alcohol-co-ethylene) nanofiber membrane (NM) were prepared for the oil/water mixture and oil-in-water emulsion separation. The addition of nanofibers could enhance the film forming ability of SiO2 nanoparticles and the mechanical property of SiO2 coatings. Besides, the preparing processes of nanofibers, N/S coatings and composite membranes possessed advantages of high throughput, lower cost, and environmental friendness. The morphology, structure, wettability of the composite membranes were characterized. The composite N/S-PM membranes were used to separate the oil/water mixtures by gravity, while the N/S-NM membranes were used to separate the oil/water emulsions by pressure driven. The separation efficiency, flux, and reusability were analyzed. The results demonstrate the good oil/water separation performance of N/S coated composites membranes, and the great potential application of which in the industrial oil/water separation.