Effect of Dialium guineense extracts on the corrosion inhibition of aluminum in alkaline solutions

The inhibiting effect of Dialium guineense extract on Aluminum corrosion in 3 M KOH and 3 M NaOH solutions were studied using gravimetric and electrochemical techniques at 303K, 323K, and 343K. The results obtained indicated that Dialium guineense extracts retarded the corrosion reaction in both alkaline media and inhibition efficiency increases as the extract concentration increases. The thermodynamics properties like Activation energy, heat of adsorption, enthalpy and entropy of adsorptions and Gibb’s free energy were also calculated. Polarization curves demonstrated that the leaf extract were mixed-type inhibitors. EIS plots indicated that the addition of the extract increases the charge-transfer resistance of the corrosion process, and hence the inhibition performance.