Adsorption and inhibition analysis of aconitine and tubocurarine alkaloids as eco-friendly inhibitors of pitting corrosion in ASTM – A47 low carbon steel in HCl acid environmen

Abstract

The research on the adsorption and inhibition analysis of aconitine alkaloid (ACA) and tubocurarine alkaloid (TBA) as eco-friendly inhibitors of pitting corrosion in ASTM – A47 low carbon steel in HCl acid was carried out under the following experimental and analytical methods: gravimetric method, electrochemical impedance spectroscopy, potentiodynamic polarization, and scanning electron microscopy method. Results revealed good inhibitors as inhibition efficiencies were recorded at 98.8% and 91.2% for tubocurarine and aconitine alkaloids, respectively. Electrochemical data strongly supported the efficacy of both inhibitors as earlier presented by the chemical methods as trend in values of charge transfer resistance, double layer capacitance, etc. Were in accordance with standards for a good inhibitor. The inhibitors were seen to be spontaneous, stabled, endothermic and physically adsorbed. Adsorption of the inhibitors on metal surface obeyed Langmuir, El-Awady, Freundlich, and Temkin adsorption isotherm. A monolayer physical adsorption was defined for the system.

Keywords

• tubocurarine
• aconitine
• alkaloids
• corrosion
• polarization
• adsorption
• impedance