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

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.