Effect of components of solanum trilobatum-L extract as corrosion inhibitor for mild steel in acid and neutral medium

The secondary metabolites of Solanum trilobatum-L was extracted from its leaves and their components were separated by column chromatography as Fraction-A and Fraction-B. The functional groups of the extracts were identified by FT-IR spectroscopy. The inhibition efficiency of the extract and its fractions were tested for mild steel in 1 M HCl and 3% NaCl by potentiodynamic polarization and electrochemical impedance spectroscopic techniques. Plant extracts act as mixed type inhibitors in all experimental conditions, and Fraction-A has more inhibition efficiency (I.E) than crude extract and Fraction-B. The protective layer of adsorbed extract constituents were confirmed by morphological study. The surface coverage and time constant for adsorption of extract molecules were calculated using R-ct and C-dl values.