Superhydrophilic and underwater superoleophobic PVDF membranes via plasma-induced surface PEGDA for effective separation of oil-in-water emulsions

This work describes the surface grafting of poly (vinylidene fluoride) (PVDF) membrane with poly (ethylene glycol) diacrylate (PEGDA) via low-pressure plasma-induced graft polymerization. The chemical composition and microstructure of the surface modified PEGylated PVDF membranes were characterized by fourier transform infrared spectroscopy (FTIR), X-rayphotoelectron spectroscopy (XPS), scanning lectron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements. By tuning polymerization conditions, a superhydrophilic and underwater superoleophobic PVDF-g-PEGDA membrane was successfully prepared. Results show that the as-prepared PVDF-g-PEGDA membranes can effectively separate oil-in-water emulsions with high separation efficiency and high fluxes under ultralow pressure. Importantly, the membrane showed excellent mechanical properties, which was also important parameter for practical application. (C) 2015 Elsevier B.V. All rights reserved.