A facile route for anchoring bio-inspired coatings on galvanized steel: Preparation and corrosion inhibition performance

Abstract

Galvanized steel is widely used in various fields due to cost-effectiveness. However, corrosion can still occur over time, especially in harsh environments, leading to the degradation of its protective zinc coating and exposure of the underlying steel to corrosive agents. This necessitates the development of additional protective measures, such as coatings, to further enhance its durability and extend its service life. Bio-inspired coatings can protect material from corrosion. In this study, we employ anodic oxidation and thiol grafting methods to prepare a lotus leaf-like superhydrophobic surface (SHS) on galvanized steel, featuring a porous coating. Dimethyl silicone oil is infused into the SHS, creating a stable lubricating liquid-infused porous surface (SLIPS) reminiscent of the Nepenthes plant. While traditional electrochemical methods offer insights into overall corrosion behavior, they cannot identify specific locations with corrosion susceptibility. This paper presents the electrochemical measurement based on droplet-scale cell for knowing the localized corrosion inhibition from superhydrophobic surface. As the comparison, traditional electrochemical impedance spectroscopy and polarization curve are also used for assessing corrosion resistance of the different coatings. The results indicate that SLIPS exhibits high corrosion resistance, mechanical durability, and self-healing properties compared to SHS. Moreover, the coating can behave self-healing property, which allows it to repair minor damages and restore its protective function. Additionally, anti-icing capabilities can be integrated into the coating to prevent the accumulation of ice, making it suitable for use in cold or freezing environments.