Corrosion mitigation potential of N-(2-(2-pentadecyl-2,5-dihydro-1H-imidazol-1-yl)ethyl)palmitamide palmitate on Q235 steel in sulfuric acid: experimental and theoretical analysis

This work investigates the use of N-(2-(2-pentadecyl-2,5-dihydro-1H-imidazol-1-yl)ethyl)palmitamide palmitate (PIP) in 1 M H₂SO₄ solution as an anti-corrosive agent for Q235 steel. By using a range of methods including electrochemical tests, weight loss, scanning electron microscopy, atomic force microscopy, contact angler, and X-ray photoelectron spectroscopy were used for the analysis of PIP inhibition potential. The extract molecules formed an adherent and homogenous protective film on the MS surface. When the PIP concentration increased, a stronger inhibition effect against corrosive attack was obtained. The highest obtained inhibition efficiency is 97.65% at 100 mg/L PIP alone and 98.04% at 25 mg/L (PIP) + 0.5 mM potassium iodide. Polarization measurements showed the mixed type inhibitive nature of the PIP with cathodic dominancy. The various kinetic and thermodynamic parameters of metal dissolution and PIP adsorption processes were evaluated from the weight loss methods in order to elaborate the adsorption mechanism. Adsorption of inhibitor obeyed Langmuir adsorption isotherm. Furthermore, an active relationship involving PIP and the Q235 steel surface was highlighted by computational studies, such as density functional theory and molecular dynamics simulation that are demonstrating outstanding mitigation properties.