Adsorption and Inhibitory Properties of Buchholzia coriacea Seed Extracts on Mild Steel Corrosion in Acidic Media

Abstract

However, due to increasing awareness of the toxic properties of most organic corrosion inhibitor compounds in current use, and the accompanying ecological and health risks, researchers are moving towards exploring more environmentally friendly inhibitor sources. [2][3][4][5][6] Available data, points towards plant extracts as the most acceptable candidate in this transition. Plants extracts are not only environmentally safe and available; they are equally effective under a wide range of corrosion environments having similar chemical composition with conventional corrosion inhibitors. [7][8][9][10][11][12][13][14] Despite the sustained interest in the use of organic extracts for corrosion protection, a major challenge has been that of deducing the detailed mechanisms of the inhibition process and determining the individual contributions of the many constituents to the total inhibiting effect of the extracts. The intricate chemical compositions of the extracts, makes it difficult to allocate the inhibition activity to any specific constituent. A novel approach developed by Oguzie and Co-Workers (2010) 15 involves evaluation of the elucidated molecular structures of the phytochemical constituents of the extracts by computer simulations of suitable models based on the Density Functional Theory (DFT). This enables theoretical assessment of corrosion inhibiting potential based on certain structure-activity relationships (SAR) to estimate basic quantum chemical/molecular descriptors identifiable with corrosion inhibition performance. Buchholzia coriacea, belonging to the family Capparidaceae is an evergreen, small to medium-sized tree growing up to 20 m tall commonly found in the rain forest zones of Africa especially Cameroon, Central African Republic, Gabon, Congo, Angola, Ghana, Nigeria, among others. The fruits of Buchholzia coriacea are oval, resembling avocado pears, with a thick and woody endocarp, yellowish when ripe; containing a