Abstract
The effectiveness of Expired Voltaren (EV) drug as corrosion inhibitor for aluminium in 1 M HCl was investigated by weight loss and electrochemical methods. Polarization curves revealed that the inhibiting action of the EV is mixed-type. The addition of the inhibitor molecules shifted the corrosion potential (E-corr) to more noble direction. The influence of temperature on the adsorption of inhibitor onto aluminium surface has been reported. Activated thermodynamic parameters were computed and discussed. The adsorption of the EV was found to obey the Langmuir adsorption isotherm. The inhibition efficiency of expired Voltaren, EV obtained by all methods was in good agreement with each other.