Durable oil-resistant superhydrophilic/air superoleophobic Al alloy surfaces for antifouling and self-cleaning

Aluminum (Al) alloys are widely used in aerospace, automotive, and electronic applications due to their low density, high specific strength, and corrosion resistance. However, surface contamination by oils and microorganisms, together with corrosion, can degrade functional performance and aesthetics, leading to increased aerodynamic drag or reduced heat dissipation. From a sustainability and lifecycle perspective, suppressing surface fouling is essential to extend service life and improve resource efficiency. Self-cleaning air superoleophobic (SOP) and superhydrophilic surfaces provide an effective strategy to prevent oil adhesion and biofouling without frequent cleaning. Nevertheless, existing fabrication approaches, such as femtosecond laser processing and fluorosilane modification, often require high energy input, incur high costs, and exhibit limited durability, particularly on smooth Al alloy substrates. Herein, a simple and scalable strategy combining microstructural surface engineering with low-surface-energy materials is developed to fabricate a robust SOP surface on Al alloys. The resulting coatings demonstrate excellent mechanical stability, long-term durability, and reliable oil-repellent performance. This work offers a sustainable and practical pathway for advanced superoleophobic surface design with broad military and civilian application potential.