Egy-dronate drug as promising corrosion inhibitor of C-steel in aqueous medium

Abstract

The effect of Egy - dronate as the corrosion inhibition of Carbon steel (CS) in 1 M HCl was studied by weight loss (WL), hydrogen evaluation (HE), Open circuit potential (EOCP), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), electron frequency modulation (EFM) and surface examination of the specimens by atomic force microscopy (AFM), energy dispersion spectroscopy (EDS) and scanning electron microscopy (SEM). The results of the inhibition efficiency (IE %) increase with increasing the concentration of inhibitor but decreases with raising the temperature. The adsorption of Egy - dronate on the C - steel surface obeys with Langmuir adsorption isotherm. The adsorption process is spontaneous, endothermic and physical adsorption. The polarization curves show that Egy - dronate is a mixed-type inhibitor tends to anodically more. The results obtained from chemical and electrochemical techniques are a good agreement quality and gives the same behavior of the adsorption of Egy-dronate drug. All techniques have proved the thin film formation adsorbed on the metal surface as a protective coated to prevent the dissolution metal in the corrosive medium, due to electrostatic attraction between unshared electrons of inhibitor molecules and the positive sites on the metal surface.