Effect of sulfate ions on corrosion of reinforced steel treated by DNA corrosion inhibitor in simulated concrete pore solution

Abstract

Abstract In this paper, a mixture of primers with a length of 20–80 bases were dissolved in a nucleic acid buffer as a deoxyribonucleic acid (DNA) corrosion inhibitor. The effect of coexisting anion SO42− on the corrosion inhibition of DNA on the chloride-induced corrosion of reinforced steel in simulated concrete pore solution was studied by linear polarization and electrochemical impedance spectroscopy (EIS). The structure of the surface membrane of steel electrode after different treatments was analyzed using X-ray photoelectron spectroscopy (XPS). The results showed that the presence of SO42− in the Cl− abundant environment adversely reduced the corrosion inhibitor efficiency of the DNA corrosion inhibitor. Interestingly, with the increase of NaCl concentration, the effect of SO42− on the corrosion resistance of DNA corrosion inhibitor and commercial corrosion inhibitor was smaller and less. More importantly, the efficiency of the adopted DNA corrosion inhibitor was higher than that of the typical commercial corrosion inhibitor (sodium phosphate) under the same condition. Findings from this study may provide new insights into the use of environmentally-friendly corrosion inhibitor in reinforced concrete structures and their performance in the presence of sulfate ions.