One-step electrospinning PVDF/PVP-TiO2 hydrophilic nanofiber membrane with strong oil-water separation and anti-fouling property

With the widespread concern of oily wastewater discharge and environmental protection, the efficient electrospun nanofiber membrane has fascinated strenuous attention owes to its uniform pore distribution and adjustable wettability. However, the common modification methods of nanofiber membranes, such as surface coating and grafting, have complicated procedures and low grafting rate, which limits their wide application in practical applications. Hence, a polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP) and inorganic titanium dioxide (TiO2) nanoparticles blend nanofiber membrane was prepared by convenient one-step electrostatic spinning. The existence of PVDF provides certain strength and chemical resistance property, and the PVP benefits the loading of TiO2 NPs and improves the hydrophilicity as well as mechanical strength of the membrane. The introduction of these three components makes the porous nanofiber membrane have a hierarchical rough structure, and appear hydrophilic in the air and oleophobic under water. The obtained membrane thus shows excellent separation efficiency (98.4%) for different emulsions, desirable antifouling property with a high flux recovery rate (FRR 95.68%) and a low total fouling ratio (15.18%) after several cycles. This strategy will be a facile and promising method of preparing reusable and functional separation membranes.