Theoretical and Experimental Investigation of a New Imidazo (1,2-a) Pyridine Derivative as a Corrosion Inhibitor for the Carbon Steel Surface in the Saline Media

Abstract

Using potentiometric polarisation measurements, a newly synthesised derivative of imidazo (1,2-a) pyridine, namely 2-(4-Bromo-phenyl)-2,3-dihydro-imidazo[1,2-a] pyridine-3-yl methylene]- phenyl-amine (BDIPMA), was investigated as a corrosion inhibitor for carbon steel in saline solution (3.5 percent NaCl). The thermodynamic characteristics observed in the experiments confirmed a physical adsorption mechanism, with adsorption following the Langmuir adsorption isotherm. The optimised structure, chemical inhibition efficiency parameter (percent IE), and physical properties in vacuum and two solvents (DMSO and H₂O), all at the equilibrium geometry, were calculated using the quantum mechanical method of the Density Functional Theory (DFT) of B3LYP with [6-311++G (2d, 2p)] level. SEM and AFM techniques were used to investigate the surface changes of carbon steel.