Eco-friendly rosin-based 6-dehydroabietic acylamino sodium as corrosion inhibitor for AA2024-T3 in alkaline solution by experimental and theoretical studies

Abstract

To enhance the corrosion resistance of AA2024-T3 in aqueous NaOH (0.01 mol·L−1), the inhibition characteristics of the synthetic rosin-based anionic surfactant, 6-dehydroabietic acylamino sodium (6-DAS), were assessed using the static weight loss method, electrochemical impedance spectroscopy, potentiodynamic polarization curves, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, UV–vis spectroscopy, and adsorption isotherm analysis. Simultaneously, quantum chemical calculations and molecular dynamics (MD) simulations were performed to predict and analyze the relationships between the molecular structure and inhibition efficiency. The results of the experiments revealed that 6-DAS achieved an inhibition efficiency of 92.95% as a valid corrosion inhibitor for AA2024-T3 in alkaline medium. Quantum chemical calculations showed that the anionic state of 6-DAS possessed a smaller band gap and a larger dipole moment than the neutral state, which indicated that anionic 6-DAS was easily adsorbed on the alloy surface in solution. This result was further proved by MD simulations, thereby strengthening the agreement between experimental results and theoretical calculations.