Scalable Fluorine-Free Superhydrophobic photo-thermal Coating Based on Boron Carbide and Candle Soot for Anti-Icing and photo-thermal De-Icing

Abstract

Ice accumulation on outdoor infrastructure such as transmission lines, wind turbine blades, and aircraft wings under freezing conditions poses severe safety risks and operational inefficiencies. Passive anti-icing strategies based on superhydrophobic surfaces have shown promise, yet their effectiveness diminishes under extreme cold, high humidity, or dynamic icing scenarios. Integrating photo-thermal functionality with superhydrophobicity offers a viable route toward anti-icing/deicing applications. In this study, a fluorine-free, mechanically robust superhydrophobic photo-thermal coating was developed by combining boron carbide (B₄C) micro-particles and candle soot nanoparticles within polydimethylsiloxane (PDMS) via a scalable spray-coating process (Candle@BC coating). The coating exhibits micro-nano hierarchical structures, achieving a water contact angle of 160° and a sliding angle of 2.5°. It demonstrates a broadband solar absorption of 96.7% and reaches a photo-thermal equilibrium temperature of 96.3 °C under 1 sun irradiation. The coating significantly delays ice formation, with freezing times prolonged by max to 5.77 times compared to bare substrates in the temperature range of -10 °C to -40 °C. Moreover, under 1 sun illumination, the coating enables rapid photo-thermal deicing, with ice droplets sliding off within 98 s at -10 °C and ice layers completely detached within 375 s. The coating also exhibits excellent mechanical durability, chemical stability, and maintains its superhydrophobicity after abrasion, tape-peeling, and exposure to corrosive liquids. This work provides a feasible and scalable approach to fabricating high-performance photo-thermal superhydrophobic coatings for all-weather anti-icing and deicing applications in harsh environments.