Quantum and Electrochemical Studies of Corrosion Inhibition Impact on Industrial Structural Steel (E410) by Expired Amiloride Drug in 0.5 M Solutions of HCl, H2SO4 and NaHCO3

Abstract

Computational and Electrochemical Studies of Corrosion Inhibition Impact on Industrial Structural Steel (E410) by Expired Amiloride Drug in 0.5 M Solutions of HCl, H 2 SO 4 and NaHCO 3 was carried out under the following experimental and analytical methods: Mass loss, thermometric, electrochemical impedance spectroscopy, potentiodynamic polarization, Quantum chemical calculations, simulation analysis and scanning electron microscopy (SEM). Findings revealed that the inhibitor is highly effective in all the tested media with surface coverage and an inhibition efficiency of 0.99/98.6, 0.92/92.2 and 0.88/88.2 % for HCl, H 2 SO 4 and NaHCO 3 respectively. Electrochemical data revealed strong adsorption of the inhibitor in both solutions as charged transfer resistance as in the increased. Thermodynamically, the inhibitor was stabled, spontaneous, physically adsorbed and associative. The theoretical data showed an energy gap of 0.019 eV close enough to allow speedy movement of the inhibitor molecules across energy levels. A good correlation of the data was found with the Langmuir isotherm compared to the El-Awady, hence a monolayer chemical adsorption as deduced. The electrochemical, SEM and theoretical data were in agreement with those of chemical experiment confirming expired amiloride as a good inhibitor of industrial structural steel (E410) in 0.5 M solutions of HCl, H 2 SO 4 and NaHCO 3 .