Non-fluorinated and durable photothermal superhydrophobic coatings based on attapulgite nanorods for efficient anti-icing and deicing

Superhydrophobic coatings are promising for anti-icing, however, preparation of those with both excellent passive anti-icing and active deicing functions is very challenging, especially via eco-friendly approaches. Here, we report non-fluorinated and durable photothermal superhydrophobic coatings based on natural attapulgite nanorods for efficient anti-icing and deicing. The attapulgite nanorods were coated with polypyrrole by oxidation polymerization of pyrrole, and then coated with hexadecyl polysiloxane by hydrolytic condensation. The photothermal superhydrophobic coatings were prepared by spray-coating the mixture of the modified attapulgite suspension and a silicone resin onto aluminum plates. The coatings show (i) excellent superhydrophobicity (water contact angle = 162.7°, sliding angle = 2.7°) due to the three-tier hierarchical micro-/nanostructure and low surface energy, (ii) excellent photothermal effect (increase in surface temperature to 70 °C in 3 min under 1 sun) due to the enlarged surface area of polypyrrole exposed to sunlight by the hierarchical micro-/nanostructure, and (iii) good mechanical, chemical and thermal stability. Consequently, in both simulated and outdoor environments, the coatings show excellent anti-icing and deicing performances, e.g., significantly prolonged water freezing time, greatly reduced ice adhesion force, fast photothermal deicing and efficient long-term (4 weeks) outdoor anti-icing/deicing. The coatings are very promising for practical applications due to the excellent performances and eco-friendly method.