Abstract
The effects of two expired antibacterial drugs, amoxicillin (Amo) cefuroxime (Cef), on the corrosion behavior of Sabic iron in 1.0 M HCl solution were examined using weight loss, galvanostatic polarization (GAP), potentiodynamic anodic polarization, and electrochemical impedance spectroscopy techniques. The outcomes showed that the inhibition efficiency increased with increasing concentrations of Amo and Cef and decreased with temperature. The activity of inhibition of these compounds was elucidated by adsorption on Sabic iron surfaces. The adsorption process obeyed the Langmuir isotherm. The activation and adsorption thermodynamic parameters have been determined and clarified. GAP studies indicated that expired Amo and Cef served as mixed inhibitors. The impedance data showed capacitive loop which indicates that charge transfer governs corrosion reactions. Expired Amo and Cef drugs are good pitting inhibitors by positively shifting the pitting potential. There is a complete agreement between the inhibition efficacies obtained from the different measurements