Electrochemical, surface analysis, computational and anticorrosive studies of novel di-imine Schiff base on X65 steel surface

Ahmed Nasser; M A Migahed; N M El Basiony; H M Abd-El-Bary; Tarek A Mohamed

doi:10.1038/s41598-023-37321-8

Electrochemical, surface analysis, computational and anticorrosive studies of novel di-imine Schiff base on X65 steel surface

Sci Rep. 2023 Jun 28;13(1):10457. doi: 10.1038/s41598-023-37321-8.

Authors

Ahmed Nasser^{1

2}, M A Migahed², N M El Basiony^{3

4}, H M Abd-El-Bary⁵, Tarek A Mohamed⁶

Affiliations

¹ The Higher Institute of Engineering, New Elmarg, El-Qalyubia, Egypt.
² Egyptian Petroleum Research Institute, Nasr City, 11727, Cairo, Egypt.
³ Egyptian Petroleum Research Institute, Nasr City, 11727, Cairo, Egypt. [email protected].
⁴ School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea. [email protected].
⁵ Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City, 11884, Cairo, Egypt.
⁶ Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City, 11884, Cairo, Egypt. [email protected].

Abstract

The inhibitory effect of di-imine-SB namely ((N¹Z, N⁴E)-N¹, N⁴-bis (4 (dimethylamino) benzylidene) butane 1,4-diamine) on X65-steel in 1 M HCl has been investigated experimentally and theoretically. The electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and weight loss outcomes display the anticorrosion properties of "di-imine- SB". The inhibitory efficiency exceeds 90% at the optimal concentration of 1 × 10^-3 M "di-imine- SB". The metal surface was examined further using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The effectiveness of the di-imine-SB is returned into its adsorption on X65-steel surface and found in agreement with Langmuir adsorption isotherm. According to the standard Gibbs free energy of adsorption [Formula: see text], di-imine-SB adsorption tends to be chemical rather than physical, it increases the activation energy ([Formula: see text]) of metal dissolution reaction and makes it hard to occur. The PDP data suggested anodic and cathodic type of the di-imine-SB inhibitor. Meanwhile, increasing the resistance of X65-steel to 301 Ω cm² after adding 1 mM of di-imine-SB confirms its protective effect. Whereas, the positive value of the fraction of electron transference (ΔN, 0.746), confirms the affinity of di-imine-SB to share electrons to the partially filed 3d-orbital of Fe forming strong protective film over X65-steel surface. Aided by Monte Carlo (MC) simulation, the calculated adsorption energy (E_ads) suggests excessive adsorption affinity of di-imine-SB on metal surface over the corrosive chlorides and hydronium ions. A good correlation between the theoretical hypothesis and the experimental inhibition efficiency has been achieved. The comparative study showed the superior of the di-imine-SB as potential corrosion inhibitor compared with those reported before. Finally, global reactivity descriptors; electron affinity (A), ionization potential (I), electronegativity (χ), dipole moment (µ), global hardness ([Formula: see text]), electrophilicity index and, Fukui indices were also calculated and found well correlated to the reactivity of di-imine-SB.