Faculty Publications
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Item Effective inhibition of mild steel corrosion by 6-bromo-(2,4-dimethoxyphenyl)methylidene]imidazo [1,2-a]pyridine-2-carbohydrazide in 0.5 M HCl: Insights from experimental and computational study(Elsevier B.V., 2021) Vranda Shenoy, K.; Venugopal, P.P.; Reena Kumari, P.D.; Chakraborty, D.A new inhibitor, 6-bromo-(2,4-dimethoxyphenyl)methylidene]imidazo [1,2-a]pyridine-2-carbohydrazide (DMPIP) was evaluated as a corrosion inhibitor for Mild Steel (MS) in 0.5 M HCl solution at 303–323 K using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. Both the techniques confirmed an increase in inhibition efficiency with the concentration of DMPIP but decrease with temperature. The highest inhibitive action (96.7%) was registered at 303 K for 500 ppm of DMPIP concentration. Polarization study revealed mixed inhibition action by DMPIP. Nyquist plot obtained for MS using EIS technique showed two capacitive loops on addition of inhibitor to HCl solution confirmed the inhibitory action of DMPIP via adsorption at the metal/solution interface. The surface morphology analysis was carried out by SEM, EDX and FTIR techniques. The adsorption process was demonstrated using Langmuir's adsorption isotherm model. The thermodynamic parameters (?Goads, ?Hoads) indicated that the adsorption was spontaneous and done by physisorption. Further, quantum chemical studies using Density Functional Theory (DFT) elucidated that the formation of Fe-DMPIP complex presumably due to the interaction of protonated form of DMPIP with the empty d orbitals of the iron atom. © 2021 Elsevier B.V.Item Exploring the potential role of quercetin in corrosion inhibition of aluminium alloy 6063 in hydrochloric acid solution by experimental and theoretical studies(Taylor and Francis Ltd., 2022) Kumari, D.; Venugopal, P.P.; Reena Kumari, P.D.; Chakraborty, D.Quercetin was evaluated as corrosion inhibitor for AA6063 in 0.5 M HCl solution by employing weight-loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), Atomic Force Microscopy (AFM), X-Ray photoelectron spectroscopy (XPS) techniques allied to quantum chemical studies. Electrochemical results substantiate that the inhibition efficacy of quercetin increases proportionally with the concentration of the inhibitor. The effect of temperature on the corrosion behavior of the alloy was studied in the range of 30–60 °C. Potentiodynamic polarization study confirms the mixed type of inhibition by quercetin with preferential control of the cathodic reaction. The adsorption of quercetin on alloy surface was explained through the Langmuir adsorption isotherm model. ΔG°ads values and its variation with the temperature ensured spontaneous adsorption through chemisorption and the process was endothermic. Further, quantum chemical parameters calculated from Density Functional Theory (DFT) method for quercetin, proved a perfect correlation between structure and corrosion inhibition efficiency. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
