A double-layer multifunctional superhydrophobic coating with excellent anti-corrosion performance based on fluorine-free chemicals

Superhydrophobic coatings with micro and nano structures have great potential in a wide spectrum of fields due to their multifunctionality. However, some disadvantages, such as poor wear resistance and containing toxic fluorine substances, greatly limit the practical application of superhydrophobic coatings. To overcome these shortcomings, herein we have prepared a double-layer coating without fluorine which demonstrates superhydrophobicity with a contact angle of 159.5°. The bottom layer of KH560-graphene oxide (GO)/epoxy (EP) and the surface layer of hydrophobic hexadecyltrimethoxysilane modified SiO2 (HDTMS-SiO2) is prepared by scraping and spraying, respectively. The bottom layer of KH560-GO/EP effectively promotes the adhesion of the top SiO2 layer and the coating maintains a superhydrophobic state even after sandpaper sanding, compressive studies and sand impact. In addition, the coating also has superior self-cleaning, anti-fouling, and anti-icing abilities, and it takes 157 s for it to ice up. More importantly, the superhydrophobic coating also exhibits outstanding corrosion resistance due to the synergistic effect of well-dispersed GO and hydrophobic surfaces. This work has demonstrated the great potential of fabricating composite superhydrophobic coatings via artificial architecture design for diversified applications.