Bionic design of multifunctional superhydrophobic fiber-based nonwoven fabric inspired by salvinia natans for efficient photothermal oil-water separation and micro plastic extraction on aero-engine filters

Existing aero-engine filters are susceptible to clogging by water, oil, microplastics and other contaminants under complex operating conditions, resulting in reduced filtration efficiency and shorter maintenance intervals. Therefore, there is an urgent need to develop a multifunctional superhydrophobic material that can efficiently separate oil and water and adsorb pollutants. Based on this, we prepared a multifunctional superhydrophobic nonwoven fabric made of ethylene-propylene side by side (ES) fiber, polyethylene terephthalate (PET) fiber, multi-walled carbon nanotubes (MWCNTs) and Mg Fe layered double hydroxide (Mg Fe LDH). This multifunctional fiber-based nonwoven fabric imitates the rough structure of the surface of salvinia natans through bionic design, which shows excellent hydrophobic performance, and the water contact angle can be as high as 160 ± 2°. At an ambient temperature of 70 °C, the oil-water separation efficiency can reach 98.8 % by thermal radiation. The oil-water separation efficiency was 98 % when the material was irradiated by halogen lamps simulating infrared light, and 97 % at ambient temperature without any light. Compared with the modified polyurethane sponge widely used for oil-water separation, the super hydrophobic multi-functional non-woven fabric has three advantages. Firstly, modified polyurethane sponge only performs a single function: oil-water separation, while superhydrophobic multifunctional non-woven fabric can achieve synergistic effects of photothermal oil-water separation, organic pollutant degradation, and microplastic extraction. In addition, the mechanical and chemical stability of superhydrophobic multifunctional non-woven fabric is stronger, which means that it has greater potential for application in aircraft engines under harsh working conditions. Finally, the preparation of multifunctional non-woven fabrics is very simple and has the potential for large-scale production.