Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E-a) and different thermodynamic parameters such as adsorption equilibrium constant (K-ads), free energy of adsorption (Delta G(ads)degrees), adsorption enthalpy (Delta H-ads degrees) and adsorption entropy (Delta S-ads degrees) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed. (C) 2010 Elsevier Ltd. All rights reserved.