Janus Polyacrylonitrile/Carbon Nanotube Nanofiber Membranes for Oil/Water Separation

Oil pollution has always been an important issue affecting the ecological and residential environment, and the development of a highly efficient oil/water separation membrane has become a hot topic. In this paper, Janus polyacrylonitrile (PAN) nanofiber membranes (PNM) were prepared by co-blending hydrophilic SiO2 nanoparticles, carbon nanotubes (CNTs) doped with PAN (PNM-SiO2 and PNM-CNT, respectively) and then using sequential multilayer electrospinning. The existence of electrostatic mutual gravitational force between SiO2 and CNTs makes the binding between the multilayer membranes exist more firmly, which is conducive to withstand the osmotic pressure brought by the liquid. In addition, Janus PAN membranes have different wetting properties; they have a micro/nanopore structure that forms a permeable channel for liquids, thus enabling efficient separation of water-in-oil and oil-in-water emulsions, which separates oil/water emulsions with flux as high as 2188 L m–2 h–1 and separation efficiency as high as 99.8%. This experiment further develops the application of Janus membranes in oil/water separation.