Constructing a hierarchical coating with photothermal superhydrophobic property by spraying and modification on polyurethane foam for anti-icing and deicing

Superhydrophobic material with photothermal conversion property is considered as a promising candidate in practical application because of its double abilities: both superhydrophobic anti-icing and photothermal deicing. Therefore, in this work, we employed a polyurethane (PU) foam with three-dimensional porous grid structure as the skeleton and carbon nanotubes (CNTs) as the photothermal conversion materials to construct a hierarchical coating with photothermal superhydrophobic property by spraying CNTs/SiO2 and modification of polydimethylsiloxane (PDMS), where a dual-size micro/nano structure was formed by adsorbing and fixing these CNTs-entangled SiO2 nanoparticles into PU foam to enhance the superhydrophobicity and light absorption capacity of coating. In this case, the water contact angle of the hierarchical coating reached up to 157.0°, accompanied by a rolling angle of 3.2°, while the water droplet hitting its wall can fully rebound within 27 ms. Importantly, the formation of hierarchical structure and the incorporation of CNTs contributed to an enhancement of light absorbance to 97.1 %, which was able to warm the coating surface up to 101.9 °C at 1 kW m−2 after 300 s illumination. Noteworthily, the surface temperature of the coating can be raised to 62.5 °C within 15 min to achieve deicing under a low ambient temperature of −20 °C. In addition, a remarkable stability and wear resistance were maintained after 10 freeze–thaw cycles and 20 friction cycles. Consequently, it can be concluded that the developed hierarchical coating with exceptional superhydrophobicity and excellent photothermal conversion performance was expected to be a potential substitute for anti-icing and deicing.