Sprayable superhydrophobic photothermal/electrothermal anti-icing coating based on evaporation-induced surfactant flocculation self-assembly

Abstract

To solve the problem of ice coverage, here we designed an all-weather superhydrophobic anti-icing coating with photothermal and electrothermal functions where silicon dioxide modified titanium nitride nanoparticles and micrometer scale titanium oxide particles synergistically regulate to form a hydrophobic photothermal top layer and carbon nanotubes serve as the electrothermal bottom layer. An in situ film-forming process based on solvent evaporation-induced surfactant flocculation self-assembly was developed to form special micro/nanosurfaces with a hierarchical growth cluster structure and multi-level mesopores, which endows good superhydrophobic properties. By relying on the special surface structure, the freezing time is delayed by nearly 4.9 times compared to that of the bare epoxy substrate. The air cushion impedance effect generated by the special structures hinders interfacial heat conduction, reduces undercooling and increases the critical nucleation energy of ice crystal formation and then effectively delays ice crystallization. The coating also exhibits excellent active de-icing ability, achieving photothermal and electrothermal de-icing in 256 s and 169 s, respectively. The synergistic effect of the photoelectrothermal capability provided by functionalized particles and the effective shielding of heat loss by the porous structure enhances the temperature rise efficiency between the ice and coating interface, thereby achieving rapid de-icing. Moreover, the coating also exhibits excellent mechanical and chemical durability in various harsh acceleration experiments involving wear and acid/alkali solution immersion. The currently designed anti-icing coatings and self-assembled film-forming processes provide a valuable reference for the design of anti-icing coatings in engineering.