Enhanced anti-icing and drag reduction of multilayer composite structure superhydrophobic surface

Abstract

In this study, a high-performance superhydrophobic coating is designed to significantly enhance anti-icing, corrosion resistance, and drag reduction on aluminum alloy surfaces. Inspired by biological microstructures of armadillos, femtosecond laser ablation is used to engineer periodic micro-nano patterns on the alloy surface. γ-aminopropyltriethoxysilane (KH550)-modified epoxy resin E51 acts as an adhesive layer to strengthen bonding. Hydrophobic is further enhanced by treating KH550-modified silica (SiO₂) nanoparticles with hexadecyltrimethoxysilane (HDTMS) and octadecyltrimethoxysilane (OTMS). The F-M@KH-SiO₂/HDTMS/OTMS superhydrophobic coating achieves a contact angle of 168.29° and a sliding angle of 1.35°, demonstrating exceptional water repellency. Anti-icing tests show a freezing delay of up to 840 s, representing a 154.55 % improvement over untreated surfaces. Drag reduction tests indicate an 11.7 % decrease in fluid resistance, attributed to the reduction in the liquid–solid contact area. The coating exhibits excellent mechanical durability after 100 abrasion and peeling cycles, and resists acidic, alkaline and salt solutions for 100 h. Electrochemical corrosion tests show a 99.17 % reduction in corrosion current density in a 3.5 wt% NaCl solution. These results suggest the potential of this bio-inspired coating for applications in aerospace, automotive, and marine industries, especially in harsh environments.