abrication of superhydrophobic surfaces with hierarchical structure and their corrosion resistance and self-cleaning properties

Abstract Mixed SiO2 nanoparticles with different ratios and contents were dispersed in hydrophobic fluorinated/silanized polymers. The mixture was bonded to the A3 steel substrate with an adhesive to obtain a superhydrophobic surface with excellent performance. The appearance, hardness, adhesion, and surface wettability of the obtained coatings with different ratios of mixed nanoparticles were characterized. Then, a series of superhydrophobic coatings with good hardness, adhesion, and crack-free surfaces were selected for further systematic investigation. The results showed that the coatings with contact angle around 151° ∼ 157° can be obtained when the hydrophobic polymer is combined with different proportions of mixed nanoparticles. The surface chemical composition of these coatings changed little while the surface structure changed significantly. The mixing ratios of nanoparticles had a significant effect on the surface morphology and sliding angle. Smaller nanoparticles had a greater impact on superhydrophobic coating performance than larger nanoparticles. Moreover, the mechanical robustness and corrosion resistance of the superhydrophobic coatings regularly changed with the proportions of smaller nanoparticles. Water droplets are easy to roll on the surface of the superhydrophobic coating with hierarchical rough structure, which makes it possesses an excellent self-cleaning performance.