New pyridinium bromide mono-cationic surfactant as corrosion inhibitor for carbon steel during chemical cleaning: Experimental and theoretical studies

New pyridinium bromide mono-cationic surfactant namely: 1-dodecyl-3-(hydroxymethyl) pyridin-1-ium bromide (DHPB) was prepared, H-1 NMR and FTIR spectroscopy are used to confirm its chemical structure. The surface-active characteristics of DHPB were determined via surface tension measurements. The efficiency of the DHPB as corrosion inhibitors for carbon steel (CS) in 2 M HCl solution evaluated by chemical and electrochemical techniques. The high inhibition efficiencies for CS in the acidic medium have been improved by raising DHPB concentration and with raising the temperature. Quantum chemical calculations (QM) and molecular dynamics simulation (MD) show the effect of the chemical structure of the DHPB on its inhibition efficiency. Moreover, the surface morphology of CS in 2 M HCl solution before and after DHPB addition using scanning electron microscope (SEM) and atomic force microscopy (AFM) confirms the protection of CS surface via the protective layer of adsorbed DHPB. (C) 2019 Elsevier B.V. All rights reserved.