Evaluation of Corrosion Mitigation Performance of 1-(3,4,5-Trimethoxyphenylmethylidene)-2-Naphthylamine (TMPNA) Schiff’s Base on Carbon Steel Using Electrochemical, Thermodynamic and Theoretical Approaches

Abstract

A novel Schiff base,1-(3,4,5-trimethoxyphenylmethylidene)-2-naphthylamine(TMPNA) has been synthesized using naphthylamine and 3,4,5-trimethoxybenzaldehyde.The effective corrosion resistance and inhibition effect of TMPNA was studied at different concentrations in water medium on carbon steel by electrochemical techniques. The protective behavior of the passive film formed by the inhibitor was characterized through electrochemical impedance spectroscopy with an increased charge transfer resistance of 954 Ω.cm2. The inhibition efficiency exhibited a gradual increase up to 92% with increase in schiff base concentration. Potentiodynamic polarization studies revealed that corrosion current decreased to 0.35 × 10−5A/cm2 with the addition of the inhibitor, TMPNA. Through various electrochemical studies such as impedance, polarization and electrochemical noise analysis (ENA), the concentration of TMPNA was optimized to 300 ppm at which the maximum corrosion resistance was observed. Inhibition efficiency was found to decrease with increase in temperature. Also, the increased activation energy (Ea) value of 27 kJ/mol confirmed that the inhibitor hindered the metal dissolution reaction. Adsorption of TMPNA on carbon steel/electrolyte interface was found to obey Langmuir adsorption isotherm. Scanning electron microscope (SEM) was used to evaluate the surface morphology. The Quantum chemical analysis (QCA) revealed that there was an electron transfer between TMPNA and the metal surface at − 6.340 eV. Molecular dynamic simulation study was carried out to investigate the adsorption of TMPNA on Fe (1 1 0) surface and adsorption energy value for the gaseous form was found to be − 4197 cal/mol.