2-Amino-3-methyl-3-(4-nitrophenyl)-5-(phenylthio)-3H-pyrrole-4-carbonitrile as effective corrosion inhibitor for mild steel in 1M HCl: Thermodynamical, electrochemical, surface and theoretical calculation
By Chandrabhan Verma and M.A. Quraishi
Published in Ain Shams Engineering Journal
2016
Abstract
Present work describes the corrosion inhibition efficiency of 2-amino-3-methyl-3-(4-nitrophenyl)-5-(phenylthio)-3H-pyrrole-4-carbonitrile (INH) on mild steel in 1M \HCl\ using weight loss, electrochemical, surface and molecular dynamics simulation methods. The weight loss results show that inhibition efficiency increasing with increasing \INH\ concentration and maximum value was obtained at 50 mg/L concentration. Adsorption of the \INH\ on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization study suggests that investigated \INH\ acts as mixed type inhibitor. \EIS\ study indicates that the \INH\ forms a protective surface film at metal/electrolyte interface. Both \SEM\ and \AFM\ studies show that surface smoothness increases due to formation of protective surface film by INH. The Monte Carlo simulation study suggests that \INH\ has strong tendency to adsorb on mild steel surface in 1M HCl. The weight loss, electrochemical, surface and molecular dynamics calculations are in good agreement.