X. Le
Sep 1, 2020
Citations
0
Influential Citations
1
Citations
Journal
Surfaces and Interfaces
Abstract
Abstract Current industrial applications of stainless steels require identifying greener and more effective methods to improve their corrosion resistance in aggressive sulfuric acid and sodium chloride media without compromising their specific bulk properties. Here, we report self-assembly of benzylphosphonic acid on stainless steel type 304 substrate by simply immersing it in an aqueous solution of benzylphosphonic acid. The proposed mechanism of spontaneous grafting based on the protonation linkages of the phosphonic functionalities onto steel surface is evidenced through X-ray photoelectron spectroscopy and electrochemical characterization results. The sorption of benzylphosphonic species creates certain physical barrier on the surface, and thus prevents steel substrates from corrosion in highly aggressive media such as sodium chloride solution. In sulfuric acid, the surface modification layers are found to be instable over time because of the presence of an excessive amount of H+ ions in the solution. To circumvent this problem, a simple heating of the self-assembled benzylphosphonic steel samples at a moderate temperature, which transmute the protonation linkages to covalent bonding of benzylphosphonate groups, is proposed. These covalently coated mono-layers are particularly characterized by a long-term stability in sulfuric acid but also provide the steel surface with a quasi-ideal inhibition performance (99.5%).