Evaluation of Vitis vinifera as a Corrosion Inhibitor for Mild Steel in 1 M HCl

The leaves of Vitis vinifera has been tried as a green corrosion inhibitor for mild steel in 1 M HCl. Its inhibitive performance was studied using mass loss method and Electrochemical methods namely potentiodynamic polarization and AC impedance method. The performance of the inhibitor at different time periods, different concentrations of the inhibitor and at various temperatures has been studied. The studies revealed that Vitis vinifera act as a good inhibitor in 1M HCl medium and the maximum efficiency was 97.31% at 2.5% v/v concentration in 24 h period and 89.42% at 323K for the same concentration of the inhibitor. Polarization study revealed that the inhibitor is mixed type with predominant anodic polarization. Activation energies of the process in absence and presence of Vitis vinifera were obtained which suggested that physisorption takes place and inhibitor is more active at lower temperatures. The adsorption isotherm models were tried and it was found to obey Langmuir, Freundlich and Temkin models.