Synthesis, assessment and corrosion protection investigations of some novel peptidomimetic cationic surfactants: Empirical and theoretical insights

Abstract

Three novel peptidomimetic cationic surfactants were synthesized in good yields. The chemical configurations of these surfactants were clarified using 1H, 13C NMR and FT-IR spectroscopy. The inhibition capacity and adsorption performance of these compounds on C-steel were studied by electrochemical techniques (Electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization (PDP) methods). The prepared compounds demonstrated outstanding protection power for the erosion of C-steel in 0.5 M HCl at 323 K. The PDP studies demonstrated that the novel surfactants behaved as mixed-type additives. The protection capacity rises with an increasing surfactant dose, with values ranging from 93.10 to 98.25% at 100 ppm. The adsorption of additives on the electrode interface follows the Langmuir model and contains chemisorption modes. The Monte Carlo (MD) simulations and density functional theory (DFT) calculations support the experimental findings and provide insight into the understanding of the adsorption features and protection performance mechanisms of the examined surfactants.