A ternary system oleophilic–hydrophobic membrane prepared by electrospinning for efficient gravity-driven oil–water separation

The preparation of composite nanofibers often can make up for the shortage of single materials in the field of oil–water separation, including separation efficiency, mechanical properties and fine flexibility. The film materials prepared by doping inorganic nanoparticles have defects of poor stability and uneven dispersion of the fiber surface. In this paper, we prepared a novel polyvinylidene fluoride (PVDF) -polystyrene (PS) -cellulose acetate (CA) ternary mixture system membrane by electrospinning. Nanosized polystyrene in the spinning process uniformly gathers on the fiber surface by interlacing PVDF and CA to manipulate the microstructure of the fiber surface. PVDF is added to increase mechanical properties. Degradable CA is selected to promote pore formation and compatibility between the other two polymers. The composite membrane has high separation efficiency, high oil flux and superior mechanical properties as demonstrated by oil/water separation test and stress–strain test. The optimized oil flux reaches 1935.67 L h⁻¹ m⁻² only driven by gravity of 0.73 kPa. Due to low energy consumption, excellent separation and more flexible regulation, this membrane may have great application value in industrial oil–water separation in the future.