Authors : Olawale Olamide, Adediran Adeolu and Talabi Segun Isaac
Abstract: The inhibition potential of Vernonia Amygdalina Stem Extract (VASE) on the corrosion of mild Carbon Steel (CS) immersed in 0.1M H2SO4 solution containing varied concentration of the inhibitor was reported. Corrosion rate measurements, inhibition efficiency, FT-IR spectroscopy and Scanning Electron Microscopic analysis (SEM) were used to assess the inhibitory properties of the extract. The highest inhibition efficiency of 97% was attained when 0.8 g L–1 of VASE was added to the acidic medium. The inhibitive ability of the extract was adjudged to be due to the presence of alkanoids, sapponins, tannins, flavonoids and phytate as indicated by the functional groups detected with FTIR analysis. The surface morphology of the corroded samples as revealed by SEM showed the formation of protective oxide layer. Furthermore, the adsorption process between the inhibitor molecules and metal surface obeyed Langmuir isotherm model and indicate a physisorption mechanism. Consequently, the extract is recommended as a safe, cheap and efficient corrosion inhibitor for mild carbon steel in acidic environment.
Olawale Olamide, Adediran Adeolu and Talabi Segun Isaac, 2020. Corrosion Inhibitory Properties of Vernonia Amygadlina Stem Extract in 0.1 M H2SO4 Solution. Journal of Engineering and Applied Sciences, 15: 3089-3094.