Abstract

Inhibition of aluminium corrosion in HCl solutions by Ficus carica leaf extract and was studied using weight loss measurements at 303, 313, 323 and 333 K. The adsorption of the inhibitor on aluminium surface follows Frumkin and Langmuir adsorption isotherms. The effect of temperature indicated that the corrosion rate and inhibition efficiency are temperature dependent in the range 303-333 K. Increase in temperature increased the corrosion rate but decreased the inhibition efficiency in the absence and presence of the inhibitor. The kinetic data obtained indicates that the adsorption follows a first order type of reaction. Physisorption mechanism has been proposed for the inhibitor. The presence of alkaloids, glycosides, saponins and tannins (having -C=O, C-OH, C=C, OH –CH₃, etc. groups) was found to have contributed greatly to the inhibition process by interacting with the aluminium surface.

Keywords

Ficus carica extract, Weight loss method, Corrosion inhibitor, Frumkin isotherm