Mechanical, chemical and wetting properties of a superhydrophobic surface based on functionalized ZrO2 on stainless steel

A stable superhydrophobic FAS-ZrO2 (FZr-ESS) surface was created by chemically etching and modifying a 304 stainless steel substrate. The effect of etching parameters such as time and temperature on the surface wetting properties was studied and optimized. The etched steel surface exhibited a honeycomb-like microstructure that, coupled with the low surface energy of the fluorinated ZrO2 nanoparticles, produced a FZr-ESS surface with a surface contact angle (CA) of 165.9° and a sliding angle (SA) of 1.7°. The presence of highly stable functionalized ZrO2 conjugated to the steel matrix contributed to the surface's outstanding mechanical stability, as confirmed by tape peeling and sandpaper abrasion tests. Furthermore, the FZr-ESS surface demonstrated exceptional chemical stability under a variety of pH conditions due to its excellent water repellency. An electrochemical test showed that the resulting surface was highly resistant to corrosion, with the corrosion current density reduced by nearly two orders of magnitude compared to bare stainless steel. The superhydrophobic FZr-ESS surface also displayed excellent long-term stability, wetting diversity, and self-cleaning behavior, making it highly versatile for a range of applications.