Schiff Base Complexes as Corrosion Inhibitors: Experimental and Theoretical Investigations

• Author(s): Dr. N. Y. Badannavar
• Paper ID: 1704373
• Page: 1025-1036
• Published Date: 30-04-2023
• Published In: Iconic Research And Engineering Journals
• Publisher: IRE Journals
• e-ISSN: 2456-8880
• Volume/Issue: Volume 6 Issue 10 April-2023

Abstract

This study explores the potential of Schiff base-metal complexes as corrosion inhibitors for mild steel in acidic environments through a combination of experimental and theoretical approaches, where Schiff bases derived from salicylaldehyde and aromatic amines were synthesized and complexed with transition metals such as Cu(II), Zn(II), and Ni(II), followed by their characterization using FT-IR, UV-Vis spectroscopy, and elemental analysis to confirm their structure and purity, and their anticorrosive efficacy was evaluated using weight-loss measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) in 1M HCl solution, revealing inhibition efficiencies exceeding 90% at optimal concentrations for certain complexes, which was attributed to the formation of a protective layer on the metal surface as evidenced by surface analysis using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), while quantum chemical calculations employing density functional theory (DFT) provided insights into the electronic structure and adsorption behavior of the complexes, with key parameters such as HOMO-LUMO energy gap, dipole moment, and Fukui indices correlating with experimental inhibition efficiencies, and molecular dynamics simulations further elucidated the adsorption mechanisms by modeling the interaction of the complexes with the steel surface, demonstrating that strong adsorption was driven by ?-electron interactions and the presence of heteroatoms in the Schiff base ligands, which facilitated electron donation to the metal surface, and additionally, the thermodynamic parameters obtained from adsorption isotherms suggested that the adsorption process was spontaneous and endothermic, indicating physisorption with contributions from chemisorption for highly efficient complexes, and the study concludes that Schiff base-metal complexes are effective, environmentally friendly corrosion inhibitors with potential for industrial applications, while also highlighting the importance of combining experimental and computational methods to achieve a comprehensive understanding of the corrosion inhibition mechanisms and guiding the rational design of more efficient inhibitors tailored for specific environments and metal substrates.

Keywords

Schiff Base Complexes, Corrosion Inhibition, Electrochemical Impedance Spectroscopy (EIS), Density Functional Theory (DFT), Adsorption Mechanism, Mild Steel in Acidic Media

Citations

IRE Journals:
Dr. N. Y. Badannavar "Schiff Base Complexes as Corrosion Inhibitors: Experimental and Theoretical Investigations" Iconic Research And Engineering Journals Volume 6 Issue 10 2023 Page 1025-1036

IEEE:
Dr. N. Y. Badannavar "Schiff Base Complexes as Corrosion Inhibitors: Experimental and Theoretical Investigations" Iconic Research And Engineering Journals, 6(10)