Construction of Lotus-Leaf Inspired High-Efficiency Polyvinylidene Fluoride/Fluorinated Polyurethane Based on Electrospinning/Electrospraying for Oil-Water Separation Membranes

Oil-contaminated water is a global problem that degrades the quality of water sources and poses a threat to human health and many ecosystems. Oil spills and the discharge of oily industrial wastewater seriously damage ecological environments. Thus, research into high-efficiency, energy-saving oil/water emulsion separation membrane materials is of great significance. Inspired by the hydrophobic mechanism of lotus-leaf surface, we used electrospinning/electrospraying technology to construct oil/water separation membranes with a nanofiber/microsphere bilayer structure consisting of polyvinylidene fluoride (PVDF) and fluorinated polyurethane (FPU). The inclusion of microspheres not only endowed the membrane material with a bilayer composite structure but greatly improved the hydrophobicity of the fiber membrane, achieving water contact angles of 150.2 degrees and 159.1 degrees in air and oil, respectively. Furthermore, the novel biomimetic separation membranes exhibited impressive self-cleaning performance for water-in-oil emulsions and excellent oil/water separation performance: the surfactant-stabilized Span80/diesel/water emulsion in the oil/water separation test reached 24 800 L m(-2) h(-1) bar(-1) with a separation efficiency of over 99.5%. Moreover, even after 50 cycles of use, the lotus-leaf bionic separation membranes maintained their excellent oil/water separation ability, meeting long-term recycling requirements. The oil/water separation and recycling performance of the lotus-leaf bionic separation membranes demonstrate their promising application in the field of oily wastewater treatment.