Author: P. Karuppasamy, S. Meena, C. Shanmuga Sundari, N. Edayadulla, K. Gayathri

DOI: http://doi.org/10.31788/RJC.2026.1919613

This study explored the corrosion inhibition potential of a novel reduced Schiff base compound, such as N, N′- bis(2-hydroxy-3,5-dinitrobenzyl)-1,4-phenylenediamine (BNSPDA), on mild steel (MS) in a 3 MNaCl by weight loss, adsorption isotherm, FE-SEM, EDX, AFM, PDP, and EIS studies. Inhibition efficiency increases with risinginhibitor concentrations but decreases with temperature. Maximum inhibition efficacy reached 65.89 %. TheLangmuir adsorption model was found to be the best fit. Polarization data indicated mixed-type inhibition, whileEIS revealed a diffusion-controlled mechanism. The -∆H* and -∆S * values supported the exothermic process andconfirmed active adsorption. Additionally, -∆Gº value reinforced spontaneous adsorption. These findings pave theway for promising mechanisms and future applications in corrosion science.

Keywords: Mild Steel; N, N′-bis(2-hydroxy-3,5-dinitrobenzyl)-1,4-phenylenediamine; Adsorption Isotherm; Thermodynamic Parameters; Electrochemical Study