Durable Design of Superhydrophobic Coatings with TiO2 Particles and Al2O3 Whiskers for the Enhanced Anti-icing Performance

Abstract

Superhydrophobic coatings with high non-wetting properties are widely applied in anti-icing applications. However, the micro-nanostructures on the surfaces of superhydrophobic coatings are fragile under external forces, resulting in reduced durability. Therefore, mechanical strength and durability play a crucial role in the utilization of superhydrophobic materials. In this study, we employed a two-step spraying method to fabricate superhydrophobic FEVE-based coatings with exceptional mechanical durability, utilizing fluorinated TiO₂ nanoparticles and fluorinated Al₂O₃ microwhiskers as the fillers. The composite coating exhibited commendable non-wetting properties, displaying a contact angle of 164.84° and a sliding angle of 4.3°. On this basis, the stability of coatings was significantly improved due to the interlocking effect of Al₂O₃ whiskers. After 500 tape peeling cycles, 500 sandpaper abrasion tests, and 50 kg falling sand impact tests, the coatings retained superhydrophobicity, exhibiting excellent durability and application capability. Notably, the ice adhesion strength on the coatings was measured at only 65.4 kPa, while the icing delay time reached 271.8 s at -15 °C. In addition, throughout 500 freezing/melting cycles, statistical analysis revealed that the superhydrophobic coatings exhibited a freezing initiation temperature as low as -17.25 °C.