Salvinia-inspired superwetting filter element for oil-water separation and microplastic removal in aero-engine fuel pre-filtration

With the rapid advancement of aviation technology, aircraft engines operate under increasingly stringent conditions, while fuel contamination by microplastics, water, and organic pollutants severely compromises operational reliability. Inspired by the hydrophobic surface of Salvinia leaves, a multifunctional nonwoven filter element (NFE) was developed for aero-engine fuel tank protection. Fabricated via melt processing of polypropylene(PP)/ polyethylene terephthalate(PET) nonwoven substrates followed by spray-coating and thermal curing of an Ni-Al-LDH@MIL-125/MWCNTs/PU/1H, 1 H, 2 H, 2H-perfluoroalkyltriethoxysilanes (POTS) composite, the NFE exhibits prominent superhydrophobicity (water contact angle > 150°) and oleophilicity. It maintains robust stability under harsh service conditions (pressure, vibration, pH 2–12 environments, and UV aging) with water contact angles consistently exceeding 150°. Integrating multiple core functionalities, the NFE achieves a maximum microplastic adsorption capacity of 0.4934 g·g −1 , 95.47% methylene blue degradation within 1 h, and high-performance oil-water separation (permeation flux: 4893.2 L·m −2 ·h −1 ); separation efficiency: > 98.65%). Notably, it retains > 99.15% separation efficiency after 10 cyclic tests and efficiently separates surfactant-stabilized emulsions. This sustainable and scalable multifunctional NFE offers a comprehensive solution for aviation fuel purification, holding significant potential to enhance engine reliability and extend service life.