Synergistic fabrication via covalent micro/nano-engineering and electrospinning: durable superhydrophobic SiO2/PAN nanofibrous membranes for efficient oil/water separation

The discharge of industrial wastewater and frequent oil spills have caused serious environmental degradation. There is an urgent need for effective oil-water separation technology to solve the problems of ecological restoration and pollution control. This study breaks through the limitations of traditional multi-step and surface modification and proposes a one-step green manufacturing strategy. The PAN matrix and SiO 2 nanoparticles are covalently linked through the -NH 2 /-C N of the bifunctional APTES molecular bridge and the Si-O-Si bond network to achieve stable interfacial anchoring. Meanwhile, during the process of preparing the separation membrane by electrospinning, hydrophobic modification and particle immobilization were completed simultaneously to construct a chemically bonded hierarchical micro/nano rough structure. This method does not require post-processing and significantly improves manufacturing efficiency and interface stability. The experimental results show that the membrane has a dual-mode separation capability, namely gravity-driven separation and continuous operation driven by the adsorption pump. It has a high separation flux and efficiency for various types of oil-water mixtures. Meanwhile, the membrane can effectively separate the water-in-oil emulsion stabilized by surfactants, with a separation efficiency exceeding 98.2%, a flux exceeding 611   L   m -2 h -1 , and a flux loss of only 6.92% after 10 cycles. It is worth noting that this membrane has continuous operational durability, maintaining an efficiency of over 97% in the simulation of industrial emulsion separation (15-minute test) and a flux recovery rate of over 94% after ethanol washing. In addition, the material has excellent environmental tolerance and holds great potential in industrial applications and oil-water separation under extreme conditions.