A superhydrophobic coating harvesting mechanical robustness, passive anti-icing and active de-icing performances

Ice accretion is a challenging issue for various residential activities and industrial facilities. However, most of the current anti/de-icing coatings fail to maintain their properties when subject to frequent mechanical wear, and their limited functionality (either anti-icing or de-icing individually) cannot meet the requirement of all-weather utilization.

Herein, a multifunctional superhydrophobic coating is prepared by compositing ferroferric oxide nanoparticles (Fe₃O₄ NPs) with fluorinated epoxy resin via an inverse infiltration process. The surface composition, morphology and wettability are systematically characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), laser scanning microscopy and contact angle tensiometer. The anti-icing and de-icing performances are evaluated by investigating the freezing delay and photothermal effect, respectively.

This coating shows outstanding water repellency (water contact angle up to 161.0°, sliding angle down to 1.4°) and can maintain superhydrophobicity within 400 cycles of tape peeling, 260 cycles of sandpaper abrasion or 25 cycles of sand impact. Besides, because the hydrophobic nano/micro hierarchical structures tremendously retard the heat transfer, the freezing process of water droplet on this coating can be apparently delayed by up to 35 min as compared to the uncoated substrate. Moreover, owing to the photothermal effect of the Fe₃O₄ NPs, the coating's surface temperature can be rapidly increased above 0 °C under infrared irradiation, which facilitates the ice melting on cold surfaces. Our work offers a versatile approach to address the icing problems in diverse weather conditions, which exhibits great prospects in various engineering applications.