Robust mussel-inspired fiber-based superhydrophobic coating with photothermal responsiveness for high-efficiency emulsion separation and pollutant adsorption in aviation engine pre-filtration

With the rapid development of the aviation industry, the environmental pollution caused by lubricant leakage is becoming increasingly prominent. Developing a multifunctional material with efficient separation performance and good environmental adaptability is of great significance for solving the problem of oily wastewater pollution in the aviation industry. In response to this demand, this study prepared a superhydrophobic multifunctional composites LDH-coffee biochar coating (LCBC) based on layered double hydroxides (LDH) and coffee biochar (CB) through hydrothermal synthesis, and innovatively sprayed it on a nonwoven fiber-based membrane to construct a separation material with micro-nano hierarchical structure. The material exhibits stable hydrophobicity with a water contact angle of 159.3°, a gravity-driven oil-water separation flux of approximately 800 L·m⁻²·h⁻¹, and an oil removal efficiency of ∼95%. In addition to oil-water separation, LCBC demonstrates supplementary dye adsorption capability, achieving a methyl orange adsorption capacity of 17.8 mg/g. In addition, this study adopted a photothermal assisted cleaning strategy, which significantly improved the reusability of the material by enhancing local photothermal effects to reduce oil adhesion. This study not only provides an efficient and environmentally friendly solution for controlling aviation lubricating oil leakage pollution, but also expands the potential application of superhydrophobic materials in the collaborative treatment of complex pollutants.