Durable Waterborne Hydrophobic Bio-Epoxy Coating with Improved Anti-Icing and Self-Cleaning Performance

This study reports an environment-friendly waterborne hydrophobic bioepoxy coating (WHBC), prepared by introducing dual-scale SiO2 nanoparticles and (3-glycidyloxypropyl) trimethoxysilane into an aqueous mixture containing the isosorbide-based epoxy and a hydrophobic curing agent. The coatings were applied on Fe foil substrates using a one-step spin-coating method. The optimal coating with 33.3 wt % SiO2 nanoparticles exhibits high hydrophobicity with a water contact angle (CA) of 153.0 ± 1.1° and a sliding angle (SA) of 14.3 ± 1.9°. This optimal coating is found to have good mechanical durability against sand erosion. It maintained a high CA of 151.3 ± 2.0° and increased SA of 23.4 ± 3.7° after mechanical sandblasting for 30 s. The as-prepared optimal coating also showed excellent self-cleaning performance and was able to retain the good self-cleaning ability after the sandblasting. In addition, the as-obtained optimal coating shows a much lower icing temperature, a significantly longer icing delay time, and a low ice adhesion strength at 0.101 ± 0.019 MPa. The developed coating is biobased and green, and it has various promising applications for marine, aerospace, energy harvesting, and sports applications.