Browsing by Author "Chauhan, D S"

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MACROCYCLIC COMPOUNDS AS GREEN CORROSION INHIBITORS FOR ALUMINIUM: ELECTROCHEMICAL, SURFACE AND QUANTUM CHEMICAL STUDIES
(International Journal of Corrosion and Scale Inhibition, 2018-09-28) Ansari, K R; Ramkumar, S; Chauhan, D S; Salman, Md; Nalini, D; Srivastava, V; Quraishi, M A
In the present work, two macrocyclic compounds namely 5,6,11,12-tetramethyl1,2,4,7,8,10 hexaazacyclododeca-4,6,10,12-tetraene-3,9-dithione (TMCD) and 5,6,11,12- tetraphenyl-1,2,4,7,8,10-hexaazacyclododeca-4,6,10,12-tetraene-3,9-dithione (TMPD) have been synthesized and for the first time reported as inhibitors against the corrosion of aluminium in 1 M hydrochloric acid. The synthesized compounds were characterized using 1H NMR and 13C NMR. The corrosion inhibition behaviour of TMCD and TMPD was studied using gravimetric measurements, electrochemical impedance spectroscopy and potentiodynamic polarization studies. The surface analysis was carried out using AFM and SEM. Theoretical studies on the adsorption behaviour of inhibitor were carried out using the Density Functional Theory method. A detailed study of the effect of temperature and the influence of immersion time is presented using weight loss technique. Potentiodynamic polarization study proves that the corrosion inhibition efficiencies of TMCD and TMPD at 400 mg L –1 concentration are 97.30% and 89.71% respectively. Both the inhibitors behaved as mixed type but exhibit cathodic predominance. The results of EIS-Nyquist plots show inductive behavior at low frequency characteristic of the electrochemical behaviour of aluminium. The increase in polarization resistance with concentration suggests the adsorption and corrosion inhibition behaviour for both TMCD and TMPD. The AFM studies reveal a considerable decrease in surface roughness in the presence of inhibitors compared to blank sample and the SEM images show a highly smooth surface of the metal sample in the presence of inhibitors. The Fukui functions, global softness and Mulliken charges reveal that the sites for electrophilic attack are the hetero atoms. The frontier molecular orbital energies, the molecular orbital energy gap and the other quantum chemical parameters corroborated the experimental observations and suggested a better performance of TMCD compared to TMPD molecule.
TRIAZOLES AS POTENTIAL CORROSION INHIBITORS: RECENT DEVELOPMENTS AND FUTURE PERSPECTIVES
(Scopus, 2023-01-01) Ramkumar, S; Nalini, D; Chauhan, D S; Quraishi, M A
Industries are continuously searching for solutions to reduce the losses caused by the massive issue of corrosion, which consumes company earnings. Prevention is the best defense against corrosion. Customized solutions using various corrosion inhibitors are one of the best methods of corrosion prevention. Organic compounds rich in heteroatoms and electron-rich cores, serve as barriers that prevent corrosion by forming an adsorbed layer. Triazoles stand out as a significant five-member nitrogen heterocycle among nitrogen-containing heterocyclic compounds with outstanding uses. Five-membered triazole come in two different structural varieties: 1,2,3-triazole and 1,2,4-triazole. Both 1,2,3- and 1,2,4-triazoles may support a wide range of substituents (electrophiles and nucleophiles) around the core structures due to their structural features, which allows for the development of numerous unique compounds. The excellent corrosion protection action of triazole derivatives can be attributed to the presence of electron-withdrawing and electron-donating substituents that allow an improved protection performance compared to that of the parent triazole molecule. Computational studies have provided evidence that the triazole- based molecules undergo donor-acceptor type interactions with metallic substrates. Triazoles are used in a variety of commercial applications, including physiologically active compounds, agrochemicals, corrosion inhibitors, dyes, and optical brighteners. This paper deals with the review on recent developments on triazole as corrosion inhibitors and their application as corrosion inhibitors and their recent trends in the field of corrosion of different metals in a variety of corrosive environments. © 2023 by Nova Science Publishers, Inc.
TRIAZOLES AS POTENTIAL CORROSION INHIBITORS: RECENT DEVELOPMENTS AND FUTURE PERSPECTIVES
(Elsevier, 2023) Ramkumar, S; Nalini, D; Chauhan, D S; Quraishi, M A
Industries are continuously searching for solutions to reduce the losses caused by the massive issue of corrosion, which consumes company earnings. Prevention is the best defense against corrosion. Customized solutions using various corrosion inhibitors are one of the best methods of corrosion prevention. Organic compounds rich in heteroatoms and electron-rich cores, serve as barriers that prevent corrosion by forming an adsorbed layer. Triazoles stand out as a significant five-member nitrogen heterocycle among nitrogen-containing heterocyclic compounds with outstanding uses. Five-membered triazole come in two different structural varieties: 1,2,3-triazole and 1,2,4-triazole. Both 1,2,3- and 1,2,4-triazoles may support a wide range of substituents (electrophiles and nucleophiles) around the core structures due to their structural features, which allows for the development of numerous unique compounds. The excellent corrosion protection action of triazole derivatives can be attributed to the presence of electron-withdrawing and electron-donating substituents that allow an improved protection performance compared to that of the parent triazole molecule. Computational studies have provided evidence that the triazole- based molecules undergo donor-acceptor type interactions with metallic substrates. Triazoles are used in a variety of commercial applications, including physiologically active compounds, agrochemicals, corrosion inhibitors, dyes, and optical brighteners. This paper deals with the review on recent developments on triazole as corrosion inhibitors and their application as corrosion inhibitors and their recent trends in the field of corrosion of different metals in a variety of corrosive environments.