Faculty Publications
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Item The inhibition of corrosion of mild steel in 0.01-0.1 N HCl solutions by N-cyclohexyl-N?-phenyl thiourea (CPTU) has been studied using potentiodynamic polarization technique. Results obtained reveal that CPTU performs excellently as anodic inhibitor for mild steel in HCl solution. The inhibitor functions through adsorption following Temkins' adsorption isotherm. The influence of parameters like temperature, hydrochloric acid concentration and inhibitor concentration on the corrosion of mild steel has also been studied.(Inhibition of corrosion of mild steel in hydrochloric acid by N-cyclohexyl-N?- phenyl thiourea) Shetty, S.D.; Shetty, P.; Nayak, H.V.S.2005Item The inhibition efficiency of Glycyl Glycine (GG) on the corrosion behaviour of Al-SiC(p) composite in 0.01, 0.1 and 1.0 N HCl solution has been investigated in the temperature range 30°-50°C using polarization techniques. The results indicate that GG acts as an anodic inhibitor and is chemisorbed following Temkin's model. The inhibitor efficiency increases with increase in inhibitor concentration and also with increase in temperature for a given inhibitor concentration. © 2006 SAEST.(Glycyl glycine as corrosion inhibitor for aluminium silicon carbide composite in hydrochloric acid) Rao, S.A.; Padmalatha; Nayak, J.; Nityananda Shetty, A.N.2006Item The inhibiting effect of N-furfuryl-N?-phenyl thiourea (FPTU) on the corrosion of mild steel in aqueous solutions of 0.05 and 0.1MHCl, as well as 0.025 and 0.05 M H2SO4 has been demonstrated using the potentiodynamic polarization technique. The polarization data showed that FPTU acts as an efficient anodic inhibitor for mild steel in both acid solutions. Avery high inhibition efficiency was evidenced in both acid solutions and it was found to vary with the concentration of the inhibitor and temperature. The obtained kinetic parameters of adsorption revealed spontaneous adsorption and a strong interaction of FPTU with the mild steel surface.(Serbian Chemical Society, The inhibition action of N-furfuryl-N?-phenyl thiourea on the corrosion of mild steel in acid media) Shetty, S.D.; Shetty, P.; Nayak, H.V.S.2006Item Corrosion inhibition of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy in a mixture of sulphuric acid and hydrochloric acid by 4-(N,N-dimethyl amino) benzaldehyde thiosemicarbazone(2011) Geetha, G.M.; Nayak, J.; Nityananda Shetty, A.N.The corrosion inhibition characteristics of 4-(N,N-dimethylamino) benzaldehyde thiosemicarbazone (DMABT) on the corrosion behavior of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy were studied at different temperatures in acid mixture medium containing varying concentrations of hydrochloric acid and sulphuric acid using Tafel extrapolation technique and ac impedance spectroscopy (EIS). The effect of inhibitor concentration, temperature and concentration of the acid mixture media on the inhibitor action was investigated. It was found that inhibition efficiencies increase with the increase in inhibitor concentration, but decrease with the increase in temperature and with the increase in concentration of the acid media. Thermodynamic parameters for dissolution process were determined. The adsorption of DMABT on both the composite and base alloy was found to be through physisorption obeying Freundlich adsorption isotherm. © 2010 Elsevier B.V. All rights reserved.Item The corrosion inhibition of maraging steel under weld aged condition by 1(2E)-1-(4-Aminophenyl)-3-(2-Thienyl)prop-2-en-1-one in 1.5 M hydrochloric acid medium(Springer New York LLC barbara.b.bertram@gsk.com, 2012) Sanatkumar, B.S.; Nayak, J.; Nityananda Shetty, A.N.The influence of 1(2E)-1-(4-Aminophenyl)- 3-(2-Thienyl)prop-2-en-1-one (ATPI) on the corrosion behavior of weld aged maraging steel in 1.5 M hydrochloric acid was studied by potentiodynamic polarization method and AC impedance (EIS) technique at different temperatures. The results showed that the inhibition efficiency of ATPI increased with the increase in the concentration of inhibitor and decreased with the increase in temperature. ATPI acts as a mixed type inhibitor without affecting the mechanism of the hydrogen evolution reaction or iron dissolution. The adsorption of ATPI on a weld aged maraging steel surface obeys the Langmuir adsorption isotherm equation. Both activation and thermodynamic parameters were calculated and discussed. ATPI inhibits the corrosion through both physisorption and chemisorption on the alloy surface. The surface morphology of the weld aged maraging steel specimens in the presence and the absence of the inhibitors was studied by the respective SEM images. © ACA and OCCA 2011.Item Inhibition effect of adsorption layer of 1-phenyl-4-(4-nitrophenyl) thiosemicarbazide on the corrosion of 18 Ni 250-grade welded maraging steel in 1.0 M hydrochloric acid medium(Kluwer Academic Publishers, 2015) Kumar, P.; Nityananda Shetty, A.N.The thiosemicarbazide derivative, 1-phenyl-4-(4-nitrophenyl)thiosemicarbazide (PNPT), was synthesized and its inhibiting action on the corrosion of welded maraging steel in 1.0 M hydrochloric acid was investigated by electrochemical methods of potentiodynamic (Tafel) polarization and electrochemical impedance spectroscopy. The inhibitor, PNPT, acted essentially as a mixed-type inhibitor with predominant cathodic action. The inhibition efficiency increased with the increase in inhibitor concentration. An inhibition efficiency of about 86 % was exhibited at 30 °C, which decreased with the increase in the temperature. The adsorption of the inhibitor layer formed was through predominant physical adsorption process. © 2014 Springer Science+Business Media Dordrecht.Item Electrochemical investigation of the corrosion inhibition mechanism of Tectona grandis leaf extract for SS304 stainless steel in hydrochloric acid(Walter de Gruyter GmbH info@degruyter.com, 2017) Kadapparambil, S.; Yadav, K.; Ramachandran, M.; Noyel Victoria, N.V.The use of Tectona grandis leaf extract as a green corrosion inhibitor for stainless steel 304 (SS304) in 2 m hydrochloric acid was investigated using electrochemical techniques. Potentiodynamic polarization studies with different inhibitor concentrations showed that the inhibitor is of mixed type, which works by affecting both cathodic and anodic reactions. Adsorption analysis using the potentiodynamic polarization and electrochemical impedance spectroscopy runs result in standard free energy of adsorption values between -20 kJ mol-1 and -40 kJ mol-1, indicating a comprehensive adsorption, which is a mixture of both physisorption and chemisorptions processes. Fourier transform infrared spectroscopy studies show the appearance of new peaks and shift in peak positions at some locations with the use of an inhibitor, which indicates the interaction between the inhibitor molecules and metal surface. Contact angle analysis indicates the formation of hydrophobic film on the metal surface. © 2017 Walter de Gruyter GmbH, Berlin/Boston.Item 2-(4-(Diethylamino)-2-hydroxybenzyledene) Hydrazinecarboamide as Corrosion Inhibitor on AA2024-T3 Aluminium Alloy in 0.5 M Hydrochloric Acid Solution(Pleiades Publishing compmg@maik.ru, 2018) Prakashaiah, B.G.; Nityananda Shetty, A.; Amitharani, B.E.A new compound 2-(4-(diethylamino)-2-hydroxybenzyledene) hydrazinecarboamide (DHBHC) was prepared by the condensation of thiosemicarbazide and diethylaminosalicyaldehyde in ethanol–water mixture and its purity was confirmed with IR, H1 and C13 NMR. Anticorrosion properties of this new compound were studied on the aluminium alloy AA2024-T3 in 0.5M HCl solution at 303 K by potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss method. The inhibition efficiency of DHBHC was found to increase with an increase of its concentration. The inhibition efficiency obtained in this study was 96 ± 3% in the presence of 10 × 10?5 M of DHBHC. The surface morphology of the alloy was investigated both in the presence and in the absence of the inhibitor by field emission scanning electron microscopy, 3D profilometry and X-ray photoelectron spectroscopy. © 2018, Allerton Press, Inc.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.