Applied Journal of Environmental Engineering Science
Doi
Abstract
Inhibition of aluminium corrosion in NaOH and HCl solutions in the absence and presence of Gmelina arborea extract was studied using thermometric method of analysis. Gmelina arborea extract acts as a better inhibitor in the acidic environment than in alkaline environment. The inhibition efficiency increased with increase in inhibitor concentration but decreased with increase in HClor NaOH corrodent concentration. The inhibiting effect of the Gmelina arborea extract could be attributed to the presence of some phytochemical constituents in the extract which may be adsorbed on the surface of the aluminium. Quantitative structure activity relationship (QSAR) of the four isolates obtained from the bulk Gmelina arborea extract proves the inhibition efficacy of the compounds through the process of back donation. Adsorption and/or binding energy data calculated from molecular dynamic simulations shows all the compounds to obey the mechanism of physical mechanism. Fukui indices showed oxygen atoms present in the phytochemical substituents as the active sites for nucleophilic and electrophilic attacks. Quantum chemical parameters and molecular dynamic simulations confirmed the spontaneity and adsorption stability of the molecules on aluminium surface respectively
