Abstract

OKAFOR, Chizoba Sandra; ANADEBE, Valentine Chikaodili  and  ONUKWULI, Okechukwu Dominic. Experimental, Statistical Modelling and Molecular Dynamics Simulation Concept of Sapium ellipticum Leaf Extract as Corrosion Inhibitor for Carbon Steel in Acid Environment. S.Afr.j.chem. (Online) [online]. 2019, vol.72, pp.164-175. ISSN 1996-840X.  http://dx.doi.org/10.17159/0379-4350/2019/v72a22.

The inhibitive performance of Sapium ellipticum leaf extract as green corrosion inhibitor for carbon steel in varying concentrations in hydrochloric acid has been investigated. To determine the adsorption strength and phenomenon of inhibition, density functional theory was adopted to model the molecular structure of the extract. Also to evaluate the inhibition efficiency weight loss, electrochemical method and statistical modelling was employed. Optimum inhibition efficiency of 89 % was achieved from electrochemical study atconditions of 1.5 g L^-1 SE concentration, temperature of 303 K and 1M HCl, respectively. The electrochemical study signifies that the phenomenon of inhibition is under mixed control and the inhibition process is in accordance with Langmuir isotherm. Fourier transform infrared spectroscopy (FTIR) of the corrosion particles and surface examination (SEM) confirms the existence of the protective film on the metal surface through the adsorption of extract species.

Keywords : Acid corrosion; carbon steel; molecular simulation; statistical modelling; electrochemical study; Sapium ellipticum leaf.

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