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• NF membranes with different structural-stable nanofiber supports were fabricated. • Effects of nanofiber support properties on NF performances were revealed. • NF-PI membrane owns high mechanical strength and long-term stability. • PVA interlayer can induce Turing structure formation and promote water transport. Nanofiber supports are promising candidates for constructing high-performance nanofiltration (NF) membranes due to their unique interconnected pores and high porosity. Conventional nanofiber supports usually possess excessive surface roughness and low structural stabilities, influencing the formation of polyamide separation layers. However, research on the effects of nanofiber support properties on the NF membrane performances is relatively few. In this study, we systematically evaluated the effects of structural properties of the nanofiber supports on the performances of the fabricated thin-film nanofiber composite (TFNC) NF membranes. The polyimide (PI) support with heat-pressing post-treatments owns a smooth surface and high structural stability due to the welding and compaction of the PI nanofibers. This promoted the formation of a polyamide separation layer with high smoothness and low fouling tendencies. Consequently, the mechanical strength and long-term operation stability of the TFNC-PI NF membrane were much stronger than that of the membranes with polyacrylonitrile (PAN) and PVDF nanofiber supports. Membrane performance analyses illustrated that the TFNC NF membranes possess notable higher water permeance while slight lower salt rejection than the commercial NF membrane. Compared to TFNC-PAN NF membranes (18∼20 L m-2h−1 bar−1), the water permeance of the structurally stable TFNC-PI NF membrane was relatively low (15–16 L m-2h−1 bar−1) due to its smaller surface filtration area and membrane pore size. Further attempts illustrated that constructing interlayers with 2 wt% polyvinyl alcohol (PVA) coating solutions resulted in the formation of clear and regular Turing structures in the polyamide surface layer. It notably enhanced the water permeance of the membrane by ∼30 % without compromising the salt rejection capability of the membrane. This study provides fundamental insights into the effects of nanofiber support properties on NF performance and feasible pathways to construct high-performance TFNC NF membranes. [ABSTRACT FROM AUTHOR]

Concerns associated with global warming and the depleting reserves of fossil fuels have highlighted the importance of high−performance energy storage systems (ESSs) for efficient energy usage. ESSs such as supercapacitors can contribute to improved power quality of an energy generation system, which is characterized by a slow load response. Composite materials are primarily used as supercapacitor electrodes because they can compensate for the disadvantages of carbon or metal oxide electrode materials. In this study, a composite of oxide nanoparticles loaded on a carbon nanofiber support was used as an electrode material for a hybrid supercapacitor. The addition of a small amount of hydrophilic FeN@GnP (Fe− and N−doped graphene nanoplates) modified the surface properties of carbon nanofibers prepared by electrospinning. Accordingly, the effects of the hydrophobic/hydrophilic surface properties of the nanofiber support on the morphology of Co3O4 nanoparticles loaded on the nanofiber, as well as the performance of the supercapacitor, were systematically investigated.