Abstract

In this investigation, we demonstrated a controlled electrodeposition method by varying the current density to generate hierarchical structures of zinc (Zn) on a carbon steel surface, which serves as hydrophobic and anticorrosion coating when further modified by stearic acid to form a covalently bonded layer that offers low surface energy. The chemical composition, surface morphology and roughness of the modified Zn coatings were analyzed using X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and confocal laser scanning microscope (CLSM). The water contact angle and wettability tests have shown that the modified Zn coating with micro/nanostructure displayed a water contact angle of 158.7° and a sliding angle of 6.4°, indicating a strong superhydrophobicity. Interestingly, the modified Zn coating with micro/nanostructure exhibited strong mechanical stability during knife scratching and adhesive tape peeling tests. Additionally, the modified superhydrophobic Zn coating showed improved corrosion resistance that provided protection to the carbon steel. The protection mechanism can be attributed to the hierarchical micro/nanostructure of Zn surface itself and the formation of hydrophobic zinc stearate complex compound. The superhydrophobic Zn coating has good application prospects in the neutral corrosion environment, which retard corrosion and reduce the adhesion of water.

Reference

1. Z. Q. Yang, L. D. Wang, W. Sun, S. J. Li, T. Z. Zhu, W. Liu and G. C. Liu, Appl. Surf. Sci., 2017, 401, 146‒155.