Reinforcement of low‐carbon steel against corrosion in acidic condition by some Schiff bases: Experimental and theoretical studies

Abstract

Interface of low‐carbon steel with acid solution in the presence of Schiff bases, 2‐((2‐hydroxybenzylidene)amino)benzoic acid (1), 2‐(((1H‐pyrrol‐2‐yl)methylene)amino)phenol (2), and Bis‐((1H‐indol‐3‐yl)methylene)cyclohexane‐1,2‐diamine (3) has been studied using different strategies includes; traditional weight loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), adsorption studies, and quantum chemical calculations. Inhibition efficiency (IE) of all the three Schiff bases on corrosion of low‐carbon steel in 1 M hydrochloric acid increases with increasing the concentration of Schiff bases. The inhibition properties of these Schiff bases are discussed by means of blocking the steel surface through adsorption. Scanning electron microscopy (SEM)‐energy dispersive X‐ray spectroscopy (EDX), atomic force microscopy (AFM), and X‐ray diffraction (XRD) studies of the steel surfaces confirmed the presence of adsorbed film. Theoretical calculations using density functional theory (DFT) are also performed to verify the experimental results.

Electrochemical and theoretical assessment of the effect of two biocides on the corrosion of petroleum steel in sulfur‐polluted Black Sea water

“…The electronic properties of the biocides, effects of the frontier molecular orbital energies, the differences between lowest unoccupied molecular orbital (LUMO), and highest occupied molecular orbital (HOMO) energies (Δ E = E LUMO − E HOMO ) were investigated. Following Koopmans’ theorem, different intrinsic molecular quantities like electronegativity ( χ , a measure of the power of a group of atoms to attract electrons towards itself), global hardness ( η , a parameter related to the resistance of an atom to a charge transfer), and global softness ( σ , which shows the reactivity of the inhibitor molecules in terms of charge transfer), electrophilicity ( ω , a descriptor of reactivity that allows a quantitative classification of the global electrophilic nature of a molecule within a relative scale and is effectively the power of a system to soak up electrons), and so forth, which are supposed to influence the overall reaction between two interacting systems, have been calculated …”

Synthesis, characterization and corrosion inhibition behavior of 2-aminofluorene bis-Schiff bases in circulating cooling water

“…There are many kinds of inhibitors, such as imidazolines, 9 Mannich bases, 10,11 quaternary ammonium salts, 12,13 acetylene alcohols, pyridines, 14 and Schiff bases. 15,16 These inhibitors contain heteroatoms (N, S, O) or electron-rich chemical bonds (p bonds). [17][18][19][20] The bis-Schiff base compounds contain N, O, and S heteroatoms and unsaturated C]N bonds, which can form strong and stable corrosion-inhibiting adsorption lms on metal surfaces, exhibiting excellent inhibition effects.…”