Exploring the Corrosion Inhibition Properties of an Anionic Gemini Surfactant Based on an Ethylenediaminetetraacetic Acid Derivative on AZ31 Alloy

Abstract

Novel sodium 2,2?-(7,16-dihexyl-8,15-dioxo-7,10,13,16-tetraazadocosane-10,13-diyl)diacetate was prepared by treating ethylenediaminetetraacetic acid dianhydride with N-dihexylamine. The surfactant was used as a corrosion inhibitor on AZ31 alloy. FT-IR spectroscopy, NMR spectroscopy and LC-MS techniques were used to characterize the synthesized anionic inhibitor. The theoretical studies, performed by using the DFT simulations revealed in-depth information on the frontier molecular orbitals and electronic properties of the inhibitor. Potentiodynamic polarization and electrochemical impedance spectroscopy methods were used to determine the corrosion inhibition ability of the synthesized surfactant. The adsorption of the surfactant on the surface of AZ31 Mg alloy obeyed Langmuir isotherm with predominantly physical adsorption and partial chemisorption. SEM-EDX and XPS were used to understand the surface morphologies of the corroded AZ31 alloy. The quantum chemical simulations were used to get the correlation between their structural, molecular geometry, and experimental results. © 2021 Wiley-VCH GmbH