A durable and photothermal superhydrophobic coating with entwinned CNTs-SiO2 hybrids for anti-icing applications

In this work, carbon nanotubes (CNTs) were grafted by silica nanoparticles to prepare CNTs-SiO2 hybrids, which were then incorporated into epoxy matrix to construct a superhydrophobic coating by a facile one-step spaying method. The surface morphology, roughness and wettability of CNTs-SiO2/epoxy coatings were tailored by changing the ratios of CNTs to SiO2. The best hydrophobicity was achieved when the ratio of CNTs to SiO2 was 1:3, showing a WCA of 159.3°. The introduction of entwined CNTs-SiO2 hybrids could not only create a micro-nano hierarchical structure to increase the water repellency, but also offer good mechanical durability of the coating surface against repeated peeling and friction damages, as well as excellent chemical stability under various harsh conditions. Benefiting from the superhydrophobicity of the coating surface and the prominent photothermal conversion capability of CNTs, the CNTs-SiO2/epoxy coating could significantly delay the water freezing time, and efficiently melt the ice layer within seconds under laser irradiation.