Novel Surfactants as Green Corrosion Inhibitors for Mild Steel in 15% HCl: Experimental and Theoretical Studies

Abstract Novel surfactants were synthesized and investigated as green corrosion inhibitor for mild steel in 15% HCl solution in various ways including weight loss, electrochemical measurements, scanning kelvin probe (SKP), scanning electron microscope (SEM) and theoretical calculations. The efficiency of the inhibitors against the corrosion of mild steel in the aggressive solution (15% HCl) were evaluated gravimetrically at various temperatures. The corrosion inhibition efficiency (η) has been increased with the increase of the inhibitor concentration, the maximum η achieved was equal to 98.97 at temperature 90 °C. The experiments results reveal that two surfactants were effective corrosion inhibitor, and because of the amphiphilic nature of surfactant molecules, the inhibitors can be adsorbed onto mild steel surface, obeying the Langmuir adsorption isotherm. Finally, Theoretical calculation parameters of quantum chemical calculation and molecular dynamic simulations further showing a definite correlation between the theoretical and experimental results.