Sprayable superhydrophobic coating with high mechanical/chemical robustness and anti-corrosion

The stability of the superhydrophobic coatings is crucial for practical application. Here, highly stable superhydrophobic coatings, with triple-scale hierarchical micro/nanostructure, were fabricated by spraying a mixture of the modified particles (micro-diatomite and nano-SiO2) on the mediate layer of epoxy resin. Large-scale paper (84 × 120 cm) as well as other various substrates, such as glass, cloth, steel, and PTFE film, were used as substrates for spraying the coatings. The coatings exhibited water repellency even after being mechanical abrased by sandpaper for 320 cm under a load of 100 g and mechanical impacted by sands (1500 g) from the height of 30 cm. In addition, the superhydrophobicity of the coatings is still retained after being subjected to the acid/base immersion test for 6 h at pH 1–13 and the heat treatment at 150–300 °C for 2 h. The anti-corrosion tests revealed the coatings possessed an ultra-high corrosion inhibition efficiency of 99.95 %, and its impedance modulus at low frequencies was 3 orders of magnitude higher than that of the substrate. The coatings also had the ability of self-cleaning, and anti-fouling properties. These features would favor their practical application.