Browsing by Author "Kathirvel, Kalaiselvi"

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ANTICORROSIVE PROPERTY OF SPIRAEA CANTONIENSISIS EXTRACT AS AN ECO-FRIENDLY INHIBITOR ON MILD STEEL SURFACE IN ACID MEDIUM
(Taylor & Francis Online, 2019) Ill-Min, Chung; Kathirvel, Kalaiselvi; Asokan, Sasireka; Seung-Hyun, Kim; Mayakrishnan, Prabakaran
The inhibitive performance of methanolic extract of eco-friendly green inhibitor Spiraea cantoniensis (S. cantoniensis) on inhibiting corrosion of mild steel (MS) in 1 M HCl was studied by weight loss, AC-impedance, Fourier transform infrared spectroscopy (FT-IR), Raman, x-ray diffraction (XRD), ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and scanning electron microscopy (SEM) analysis. The results showed that the corrosion rate significantly decreased in the presence of the S. cantoniensis inhibitor with a gradual increase in inhibition efficiency at an increased inhibitor concentration. The temperature studies were conducted which included activation energy (Ea), change in enthalpy (ΔH°ads), change in entropy (ΔS°ads), change in free energy (ΔG°ads) and heat of adsorption (Qads). These calculations were helpful to determine the reaction mechanism and proved it as a physisorption type following the Langmuir adsorption isotherm. The analysis of the protective film using FT-IR, Raman, XRD, and SEM analysis clearly showed the potentiality of S. cantoniensis in blocking the MS surface to prevent corrosion by 1 M HCl. The solution analysis via AAS and UV-Vis showed the inhibitive effect of the inhibitor (S. cantoniensis) in both inhibitive and the uninhibitive solution exhibiting the adsorption of the phytochemical molecules on the MS surface.
CORROSION RESISTANCE OF MILD STEEL IN SULPHURIC ACID SOLUTION BY COREOPSIS TINCTORIA EXTRACT: ELECTROCHEMICAL AND SURFACE STUDIES
(2018-07-24) Kathirvel, Kalaiselvi; Ill-Min, Chung; Seung-Hyun, Kim; Mayakrishnan, Prabakaran
The purpose of this paper is to investigate the inhibitive performance of Coreopsis tinctoria (C. tinctoria) plant extract for the corrosion of mild steel in 0.5 M H2SO4.
ECOFRIENDLY GREEN INHIBITOR FROM HEMEROCALLIS FULVA AGAINST ALUMINUM CORROSION IN SULPHURIC ACID MEDIUM
(Taylor & Francis Online, 2020-01-15) Ill-Min, Chung; Ramalingam, Malathy; Seung-Hyun, Kim; Kathirvel, Kalaiselvi; Mayakrishnan, Prabakaran; Mayakrishnan, Gopiraman
This research work aims to identify a non-toxic, cheap, and effective greener inhibitor from Hemerocallis fulva (H. fulva) for corrosion of aluminum in a 1 M H2SO4 medium at different concentrations and temperatures. We investigated the inhibitive effect of H. fulva extract in a 1 M H2SO4 solution on aluminum using weight loss measurements with various concentrations and temperatures. Evaluations of the mechanism of corrosion inhibition by potentiodynamic polarization and AC-impedance analysis were also performed. The nature of the adsorption and morphology on the surface of aluminum were performed by atomic force microscopy (AFM) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) studies. The results suggested that the H. fulva extract can be used on aluminum as an efficient eco-friendly corrosion inhibitor in 1 M H2SO4 solution as identified using weight loss because the maximum corrosion inhibition efficiency η (%) was found to be 89% at 600 ppm at 303 ± 1 K. It was found that maximum η (%) was obtained at 303 ± 1 K compared to other temperatures (313, 323, and 333). The activation energy (Ea) was higher in the presence of inhibitor than in the absence of inhibitor, showing the temperature dependency of inhibition. The positive values of enthalpy of activation ΔH° and entropy of activation ΔS° reflect the endothermic and disordered nature of the reaction. Physical adsorption was proposed for the inhibition and the process followed the Langmuir adsorption isotherm. The negative value of ΔGoads indicates spontaneous adsorption. Polarization measurements clearly indicated that the H. fulva acts as a mixed inhibitor and the η (%) increases with inhibitor concentration. SEM-EDX, AFM, and XPS studies confirmed the formation of a protective layer over the surface of the aluminum specimen.
HIGHLY EFFICIENT LIGULARIA FISCHERI GREEN EXTRACT FOR THE PROTECTION AGAINST CORROSION OF MILD STEEL IN ACIDIC MEDIUM: ELECTROCHEMICAL AND SPECTROSCOPIC INVESTIGATIONS
(Elsevier, 2016-02) Mayakrishnan, Prabakaran; Seung-Hyun, Kim; Kathirvel, Kalaiselvi; Venkatesan, Hemapriya; Ill-Min, Chung
A methanol extract of Ligularia fischeri was studied for its inhibitive effect on the corrosion of mild steel in a 1 M hydrochloric acid medium, using the metrics of weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The corrosion rate of mild steel and Ligularia fischeri's inhibition efficiencies were calculated. The inhibition efficiency [η (%)] was observed to increase with increasing concentrations of Ligularia fischeri. A maximum inhibition efficiency of 92% was achieved using 500 ppm of the inhibitor. The weight loss experiments were performed at different temperatures to understand the thermodynamic mechanism of inhibition. A mixed inhibition mechanism was proposed for the effects of Ligularia fischeri extract, as revealed by the potentiodynamic polarization technique. A solution analysis by atomic absorption spectroscopy (AAS) for mild steel showed decreased dissolution of iron in the presence of Ligularia fischeri. The adsorption mechanism and surface morphology of the mild steel, both with and without the inhibitor, were studied using UV–visible, Fourier transform infrared (FT-IR), Raman, wide-angle X-ray diffraction (WAXD), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS), and atomic force microscopy (AFM).
HIGHLY EFFICIENT LIGULARIA FISCHERI GREEN EXTRACT FOR THE PROTECTION AGAINST CORROSION OF MILD STEEL IN ACIDIC MEDIUM: ELECTROCHEMICAL AND SPECTROSCOPIC INVESTIGATIONS
(Elsevier, 2016-02) Mayakrishnan, Prabakaran; Seung-Hyun, Kim; Kathirvel, Kalaiselvi; Venkatesan, Hemapriya; Ill-Min, Chung
A methanol extract of Ligularia fischeri was studied for its inhibitive effect on the corrosion of mild steel in a 1 M hydrochloric acid medium, using the metrics of weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The corrosion rate of mild steel and Ligularia fischeri's inhibition efficiencies were calculated. The inhibition efficiency [η (%)] was observed to increase with increasing concentrations of Ligularia fischeri. A maximum inhibition efficiency of 92% was achieved using 500 ppm of the inhibitor. The weight loss experiments were performed at different temperatures to understand the thermodynamic mechanism of inhibition. A mixed inhibition mechanism was proposed for the effects of Ligularia fischeri extract, as revealed by the potentiodynamic polarization technique. A solution analysis by atomic absorption spectroscopy (AAS) for mild steel showed decreased dissolution of iron in the presence of Ligularia fischeri. The adsorption mechanism and surface morphology of the mild steel, both with and without the inhibitor, were studied using UV–visible, Fourier transform infrared (FT-IR), Raman, wide-angle X-ray diffraction (WAXD), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS), and atomic force microscopy (AFM).
INHIBITION BEHAVIOR OF TRAGIA INVOLUCRATA L. PHENOLIC COMPOUNDS AGAINST ACIDIC MEDIUM CORROSION IN LOW CARBON STEEL SURFACE
(Elsevier, 2019-03) Ill-Min, Chung; Seung-Hyun, Kim; Venkatesan, Hemapriya; Kathirvel, Kalaiselvi; Mayakrishnan, Prabakaran
The antioxidant and anticorrosive effect of Tragia involucrate L. (T. involucrate L.) was evaluated to aid in finding new compounds which can be used for various purposes. The total phenolic (TPC) and flavonoid content (TFC), antioxidant activity (DPPH, reducing potential and phosphomolybdenum), and electrochemical measurements, Fourier transform infrared (FT-IR), UV–visible (UV–vis) spectral analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM–EDX) and atomic force microscopy (AFM) were done to analyze the potency and also the inhibition efficiency of T. involucrate L. against 1 mol·L−1 HCl on low carbon steel. The TPC (145.21 mg GAE·g−1), TFC (52.32 mg QCE·g−1) and antioxidant activities were found to be significant. The electrochemical studies performed by AC impedance measurements showed significant changes in impedance spectra without causing any change in Nyquist plots. An increase in charge transfer resistance (Rct) values, a blockage in active sites exhibiting cathodic and anodic inhibition shows the action of inhibitor on low carbon steel. This was later confirmed by FT-IR and UV–vis which showed variation in absorption band at 270 nm and 273 nm (before immersion) and 208 and 281 nm (after immersion). The same was tested again by SEM–EDX through altered strength of iron and oxygen bands and using AFM by analyzing the change in average roughness values of low carbon steel before (61.65 nm) and after (97.87 nm) exposure to blank acid without inhibitor, while it was shifted to 81.58 nm in acid with inhibitor. All these results showed strong evidence adding values to T. involucrate L. plant extract in inhibiting corrosion on low carbon steel and by promoting antioxidant importance of the extract which helps in scavenging free radicals.
INHIBITION BEHAVIOR OF TRAGIA INVOLUCRATA L. PHENOLIC COMPOUNDS AGAINST ACIDIC MEDIUM CORROSION IN LOW CARBON STEEL SURFACE
(Elsevier, 2019-03) Ill-Min, Chung; Seung-Hyun, Kim; Venkatesan, Hemapriya; Kathirvel, Kalaiselvi; Mayakrishnan, Prabakaran
The antioxidant and anticorrosive effect of Tragia involucrate L. (T. involucrate L.) was evaluated to aid in finding new compounds which can be used for various purposes. The total phenolic (TPC) and flavonoid content (TFC), antioxidant activity (DPPH, reducing potential and phosphomolybdenum), and electrochemical measurements, Fourier transform infrared (FT-IR), UV–visible (UV–vis) spectral analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM–EDX) and atomic force microscopy (AFM) were done to analyze the potency and also the inhibition efficiency of T. involucrate L. against 1 mol·L−1 HCl on low carbon steel. The TPC (145.21 mg GAE·g−1), TFC (52.32 mg QCE·g−1) and antioxidant activities were found to be significant. The electrochemical studies performed by AC impedance measurements showed significant changes in impedance spectra without causing any change in Nyquist plots. An increase in charge transfer resistance (Rct) values, a blockage in active sites exhibiting cathodic and anodic inhibition shows the action of inhibitor on low carbon steel. This was later confirmed by FT-IR and UV–vis which showed variation in absorption band at 270 nm and 273 nm (before immersion) and 208 and 281 nm (after immersion). The same was tested again by SEM–EDX through altered strength of iron and oxygen bands and using AFM by analyzing the change in average roughness values of low carbon steel before (61.65 nm) and after (97.87 nm) exposure to blank acid without inhibitor, while it was shifted to 81.58 nm in acid with inhibitor. All these results showed strong evidence adding values to T. involucrate L. plant extract in inhibiting corrosion on low carbon steel and by promoting antioxidant importance of the extract which helps in scavenging free radicals.
POLYGONATUM ODARATUM EXTRACT AS AN ECO-FRIENDLY INHIBITOR FOR ALUMINUM CORROSION IN ACIDIC MEDIUM
(Taylor & Francis Online, 2018-04-16) Mayakrishnan, Prabakaran; Seung-Hyun, Kim; Asokan, Sasireka; Kathirvel, Kalaiselvi; Ill-Min, Chung
The corrosion of aluminum specimens in Polygonatum odaratum (P. odaratum) extract was studied using weight loss measurements, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy (SEM), and electron dispersive X-ray spectroscopy (EDX) techniques. The inhibition efficiency of the aluminum specimens in the presence of inhibitor from P. odaratum plant extract at 303–333 ± 1 K was evaluated with the weight loss technique. The results indicate the inhibition efficiency of P. odaratum plant extract increased with increased concentration of the inhibitor and decreased temperature in an acidic medium. The corrosion inhibition properties of the P. odaratum plant extract for aluminum specimen corrosion in 1 M HCl were analyzed using polarization studies and electrochemical impedance studies, which clearly showed a mixed-type inhibitor. UV-visible spectroscopy, Fourier transform infrared (FT-IR), SEM, and EDX revealed the surface morphology in the presence and absence of inhibitor on the metal surface. The results indicated the feasibility of using the P. odaratum plant extract as a corrosion inhibitor in acid environments.