Strong mechanical and durable superhydrophobic photothermal MWCNTs/SiO2/PDMS/PVDF composite coating for anti-icing and de-icing

A MWCNTs/SiO2/PDMS/PVDF superhydrophobic photothermal composite coating has been prepared by a simple scraping method. The coating can be scraped on different substrates and exhibit excellent superhydrophobic photothermal performance. The obtained superhydrophobic photothermal coating not only has excellent light absorption, acid and alkali resistance, weather resistance and simple preparation process, etc., but also has strong abrasion resistance, adhesion ability and weak light ice-melting performance. The coating still can keep a good superhydrophobic performance after about 80 and 30 abrasion cycles (~40 and 15 m) with about 3.3 and 8.2 kPa pressure on a 360-mesh sandpaper, respectively. Based on the method of Paints and Varnishes-Cross-Cut Test, the adhesion level of the coating can be classified as grade 1. Under 11.5 °C ambient temperature, the coating surface can reach a saturation temperature of around 30 °C with only 0.2 sun irradiation within 5 min. At −15 °C and no light irradiation, compared with the bare aluminum substrates, the coating can delay the freezing time more than twice. At −15 °C, the 0.2 sun irradiation intensity is enough for the coating to prevent 100 μL water droplets from freezing. In contrast, without the coating, the 100 μL water droplet started to freeze after 93 s with 0.2 sun irradiation and it was completely frozen after 285 s. Besides, the ice pellet began to melt after 271 s through the photothermal effect of the coating with low irradiation intensity of 0.2 sun at −15 °C. However, for the same ice pellet, the ice melting cannot occur without photothermal coating under the same conditions. The superhydrophobic photothermal coating shows good application potential in practical engineering.