Studying the effect of two isomer forms thiazole and thiadiazine on the inhibition of acidic chloride-induced steel corrosion: Empirical and Computer simulation explorations
By El-Lateef, Hany M. Abd; Sayed, Abdelwahed R.; Shalabi, Kamal
Published in Journal of Molecular Liquids
2022
Abstract
Two isomeric forms thiadiazines (AZIN) and thiazoles (AZOL) are produced through a simple reaction of monohydrazone with α-haloketohydrazonoyl derivatives in the alkaline medium. The prepared materials were characterized through spectral information. The corrosion inhibition performance of AZIN and AZOL for the C-steel corrosion in a 15% hydrochloric acid solution was evaluated via Open circuit potential (EOCP) vs. time, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) techniques. The inhibition efficiencies of AZIN and AZOL at an optimum concentration (2.0 × 10-3 M) are 96.4% and 98.3% at 50 °C, respectively. The assessed values of the standard adsorption free energy (ΔGads0) revealed the typical behavior of physisorption and chemisorption of AZIN and AZOL on C-steel and followed the Langmuir isotherm model. Surface morphology studies by FTIR and FESEM analyses confirmed the adsorption of the AZIN and AZOL molecules on the C-steel interface. Density functional theory (DFT) calculations and Monte Carlo (MC) simulations exhibited that the efficiency of the AZIN and AZOL associates well with their structures and this protection was due to their adsorption on metal surfaces.