Browsing by Author "Hemapriya V"

Now showing 1 - 13 of 13

ANTI-CORROSION PROPERTIES OF BENZOTHIAZOLE DERIVATIVES FOR MILD STEEL IN 1M H2SO4 SOLUTION
(Chemical Science Review and Letters, 2014) Hemapriya V; Parameswari K; Chitra S
The corrosion inhibition performance of benzothiazole derivatives namely, 2-phenylbenzothiazole(PBT), 2-(4- methoxy-phenyl)benzothiazole(MPB) and 2-(3,4,5- trimethoxy-phenyl)benzothiazole(TPB) on mild steel in 1M H2SO4 has been studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy. The experimental results showed that the inhibition efficiency increases with increase in inhibitor concentration but decreases with increasing temperature. The inhibition has been assumed to occur via adsorption of inhibitors on mild steel surface. This is supported by the results obtained from scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Adsorption of inhibitors on mild steel surface follows Langmuir adsorption isotherm. The activation energy and free energy of adsorption for the inhibition reaction support the mechanism of physical adsorption. Potentiodynamic polarization measurements indicate that the studied benzothiazole derivatives act as mixed inhibitors. Quantum chemical calculations have been performed and quantum chemical indices were calculated to supplement the experimental results.
ANTICORROSIVE POTENTIAL OF ETHANOL EXTRACT OF DELONIX ELATA FOR MILD STEEL IN 0.5 M H 2 SO 4 - A GREEN APPROACH
(Bulgarian Chemical Communications, 2019) Mahalakshmi D; Unnisa C.B.N; Hemapriya V; Subramaniam E.P
The phytochemical constituents of Delonix elata, characterized by gas chromatography-mass spectroscopy (GC-MS) and their inhibitive action on mild steel in 0.5 M H2SO4 medium, are discussed in the present study. The impedance and polarization techniques showed a similar trend as regards concentration and inhibition efficiency. The optimized concentration of D. elata (10 % v/v) resulted in high inhibition efficiency (85.96%). To confirm the adsorption of inhibitors on the mild steel surface, morphological studies of the latter were carried out by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and atomic force microscopy (AFM) techniques for both uninhibited and inhibited specimens. The electrochemical measurements and surface studies were well associated with each other.
ANTICORROSIVE POTENTIAL OF ETHANOL EXTRACT OF DELONIXELATA FOR MILD STEEL IN 0.5 M H2SO4 - A GREEN APPROACH
(Bulgarian Academy of Sciences, Union of Chemists in Bulgaria, 2019-03-18) Mahalakshmi D; Unnisa C B N; Hemapriya V; Subramaniam E P; Roopan S M; Chitra S; Chung, Ill-Min; Kim, S H; Prabakaran M
The phytochemical constituents of Delonixelata, characterized by gas chromatography-mass spectroscopy (GCMS) and their inhibitive action on mild steel in 0.5 M H2SO4 medium, are discussed in the present study. The impedance and polarization techniques showed a similar trend as regards concentration and inhibition efficiency. The optimized concentration of D. elata (10 % v/v) resulted in high inhibition efficiency (85.96%). To confirm the adsorption of inhibitors on the mild steel surface, morphological studies of the latter were carried out by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and atomic force microscopy (AFM) techniques for both uninhibited and inhibited specimens. The electrochemical measurements and surface studies were well associated with each other.
ASTER KORAIENSIS AS NONTOXIC CORROSION INHIBITOR FOR MILD STEEL IN SULFURIC ACID
(Elsevier, 2017-08-25) Prabakaran M; Kim, Seung-Hyun; Mugila N; Hemapriya V; Parameswari K; Chitra S; Chung, Ill-Min
Inhibition efficiency of Aster koraiensis leaf extract toward corrosion of mild steel in 1 M H2SO4 solution was investigated using weight loss, electrochemical, FT-IR, SEM, and EDX methods The individual phenolic compounds present in A. koraiensis extract were identified. Maximum efficiency of 90.53% was achieved at 2000 ppm of the extract. The corrosion kinetic parameters determined from the polarization curves indicated that the extract acted as a mixed-type inhibitor. Adsorption of the inhibitor on the mild steel surface obeyed the Langmuir isotherm. SEM investigations confirmed the formation of inhibition layer unto the metal surface by compounds present in the extract.
BIOSYNTHETIC GREENER MOVE TOWARDS NANOSIZED SILVER BY DIOSPYROS MONTANA LEAF EXTRACT AND THEIR ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES
(Blue Eyes Intelligence Engineering & Sciences Publication, 2020-01-04) Kanchana P; Arunadevi N; Hemapriya V; Shanmuga Sundari S; Prabha Devi B
Synthesis of nanomaterials by eco-friendly method is being exploited by chemists because of several advantages over other conventional techniques. The current investigation reports the green approach for Diospyros Montana(DM) silver nanosized particles which has high antimicrobial and antioxidant activities. The synthesized nanosized particles were investigated by several techniques such as IR, Ultra violet, X-Ray Diffraction, Transmission Electron Microscope and AFM studies. Crystalline size of the silver nanoparticle is in the range of 47.05 nm which was clear from the powder X-rd studies. The silver nanoparticls prepared were tested for their antimicrobial potential against E.coli, B.subtilis, C.albicans and A.flavus species and was found to reveal excellent activity because of its volume ratio and high surface.The DPPH assy was used to find scavenging activity of free radicals. In this work we report the silver nanoparticles by aqueous Diospyros Montana leaf extract and its potential for free radical scavenging.
CORROSION BEHAVIOR OF MILD STEEL IN HYDROCHLORIC ACID SOLUTION IN PRESENCE OF NICOTINIC ACID DERIVATIVES
(International Journal of Current Research, 2014-01) Hemapriya V; Savithri K; Parameswari K; Chitra S
The inhibition effect of the synthesized organic inhibitor namely its benzylidine derivative investigated using weight loss, measurements. The inhibition efficiencies obtained from all methods employed are in good agreement with each other. The obtained results show that the compounds NAH and NABH are very good inhibitor solution. The inhibition efficiency increases with increase of inhibitor concentration. Changes in impedance parameters (R surface, leading to the formation of a protective film. Tafel polarization measurements showed that the inhibitors are mixed type. Adsorption of the inhibitor on the surface of the mild steel in 1M hydrochloric acid was found to obey Langmuir’s adsorpti energy of adsorption process were calculated and discussed
CORROSION INHIBITION BEHAVIOR OF BENZOTHIAZINE DERIVATIVE ON LOW CARBON STEEL IN ACID MEDIUM: ADSORPTION AND QUANTUM CHEMICAL INVESTIGATIONS
(World Scientific Publishing Co Pte Ltd, 2018-12-26) Hemapriya V; Chung, Ill-Min; Parameswari K; Chitra S; Kim, Seung-Hyun; Prabakaran M
The inhibitive performance of 2-[(5-phenyl-1,3,4-oxdiazol-2-yl)methyl]-2H-benzo[b] [1,4] thiazin-3-one (POBT) for low carbon steel corrosion in 1 M H2SO4 has been evaluated by non-electrochrmical, and electrochemical measurements. Efficiency of the inhibitor enhanced with inhibitor concentration and declined with rise in temperature. 92.39% inhibition efficiency was attained using 0.1mM of POBT. Anticorrosive effect of the inhibitor is owing to the adsorption of POBT molecules on the metal surface. Mono layer adsorption of inhibitor was favored by observing the best fit with Langmuir isotherm. Polarization measurements reveal that the inhibitor behaves as mixed type. Surface analysis by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) confirm the existence of a protective film of POBT on low carbon steel surface. Quantum chemical parameters obtained using density functional theory (DFT) method complements the above results.
DRY AND WET LAB ANALYSIS ON BENZOFUSED HETEROCYCLIC COMPOUNDS AS EFFECTIVE CORROSION INHIBITORS FOR MILD STEEL IN ACIDIC MEDIUM
(Elsevier, 2016-08-25) Hemapriya V; Prabakaran M; Parameswari K; Chitra S; Kim, Seung-Hyun; Chung, Ill-Min
The influence of two benzofused heterocyclic compounds, namely 2-phenylquinazolin-4(3H)-one(PQO) and 2-phenyl-4H-benzo[d]oxazin-4-one(POO) in controlling mild steel corrosion in 1 M H2SO4 solution was investigated using gravimetric and electrochemical methods. The experimental results revealed that both the inhibitors inhibit corrosion and their inhibition efficiency follows the order PQO > POO. A mixed mode of inhibition from polarization and a charge transfer mechanism from impedance study in the absence and presence of inhibitors were found. The passive film formed on the mild steel surface was characterized using SEM-EDX. Quantum chemical parameters derived using DFT performed at B3LYP/6-31G(d, p) level were used to correlate the molecular structure.
EXPERIMENTAL AND THEORETICAL STUDIES ON INHIBITION OF BENZOTHIAZINES AGAINST CORROSION OF MILD STEEL IN ACIDIC MEDIUM
(Emerald Publishing Limited, 2017-05-02) Hemapriya V; Prabakaran M; Parameswari K; Chitra S; Kim, Seung-Hyun; Chung, Ill-Min
Purpose The aim of this paper was to investigate the corrosion inhibition potential of two synthesized benzothiazines, namely, 3,4-dihydro-2-methoxycarbonylmethyl-3-oxo-2H-1,4-benzothiazine (1) and ethyl 3-oxo-3,4-dihydro-2H-1,4-benzothiazine-2-carboxylate (2) on mild steel corrosion in 1M H2SO4. Design/methodology/approach Corrosion inhibition efficiency (IE%) was studied by weight loss measurements, potentiodyanmic polarization method, alternating current (AC) impedance spectroscopy, fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy. Quantum chemical approach was used to complement the experimental results. Findings The results obtained show that the IE% increased with inhibitor concentration and follow the order 2 > 1, obeying Langmuir adsorption isotherm. The calculated quantum chemical indices were consistent with experimental results. Originality/value This paper provides information on the inhibitive properties of new set of benzothiazines on mild steel corrosion in 1M H2SO4.
INHIBITING EFFECTS OF BENZOTHIAZOLE AMINE SCHIFF BASES ON THE CORROSION OF MILD STEEL IN ACID ENVIRONMENT
(International Journal of Recent Scientific Research, 2014-08) Hemapriya V; Parameswari K; Chitra S
The corrosion inhibition of mild steel in 1M H2SO4 solution by Benzothiazol-2-yl- benzylidene amine (BBA) & 2-(Benzothiazol-2-yliminomethyl)-phenol (BIP) has been studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy. The experimental results showed that the inhibition efficiency increases with increasing inhibitor concentration but decreases with increasing temperature. The adsorption of inhibitors on the mild steel surface obeyed the Langmuir adsorption isotherm. Potentiodynamic polarization curves revealed that the compounds act as mixed type inhibitors. The impedance measurements showed a change in the charge transfer resistance and double layer capacitance indicating adsorption of inhibitors on the mild steel surface. Surface analysis of mild steel has been carried out using scanning electron microscopy (SEM) with EDX and Fourier transform infrared (FT-IR) spectroscopy. Quantumchemical calculations have been performed and several quantum chemical indices were calculated in order to complement the experimental results
THE INHIBITION EFFECT OF THIAZINE COMPOUNDS TOWARDS THE CORROSION OF MILD STEEL IN SULPHURIC ACID MEDIA
(Rasayan Journal of Chemistry, 2012-12) Hemapriya V; Parameswari K; Bharathy G
The inhibition effect of thiazines (AT, CBT & NBT) on mild steel corrosion in 1M sulphuric acid (H2SO4) was investigated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The result showed that corrosion rate was significantly decreased in presence of the inhibitors. The inhibiting action increases with the concentration of thiazine compounds to attain 99 % at 0.5mM of (AT). The increase in temperature leads to a decrease in the inhibition efficiency of the compounds in the temperature range 308-353K. Adsorption of thiazines on the mild steel surface in 1M H2SO4 obeyed the Langmuir adsorption isotherm. EIS measurements showed an increase in charge transfer resistance (Rct) with concentration. Potentiodynamic polarization study showed that the inhibitors act as mixed type, controlling both the anodic and cathodic reactions. Surface analysis by SEM confirmed the formation of adsorbed protective layer of the inhibitor on the steel surface.
INHIBITION EFFECTS AND THEORETICAL STUDIES OF PYRAZOLIDINE-DIONES AS CORROSION INHIBITORS FOR MILD STEEL IN 1M H2SO4 SOLUTION
(INPRESSCO, 2014-12-01) Hemapriya V; Saranya P; Parameswari K; Chitra S
Corrosion inhibition of mild steel in the presence of different concentrations of 1-phenylpyrazolidine-3,5dione(PPD)and4-(4-benzylidine)-1-phenylpyrazolidine-3,5-dione(BPP) in 1M H2SO4 solution has been studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy. The effect of temperature on the corrosion behavior of mild steel has been examined in the temperature range of 303–333 K. The inhibition efficiency increases with increasing inhibitor concentration but decreases with increasing temperature. The activation energy and free energy of adsorption for the inhibition reaction support the mechanism of physisorption. The adsorption of inhibitors on mild steel surface is endothermic, spontaneous and consistent with the Langmuir adsorption isotherm. Potentiodynamic polarization measurements indicate that PPD & BPP act as mixed inhibitors. Surface analysis of mild steel has been carried out using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy which reveals the adsorption of inhibitors on mild steel surface. Quantum chemical calculations have been performed at B3LYP/6-31G(d,p) level to calculate the electronic properties of the molecules inorder to complement the experimental results. The optimized structures, position of HOMO and LUMO of the molecules are obtained.
LINEAR POLYESTERS AS EFFECTIVE CORROSION INHIBITORS FOR STEEL REBARS IN CHLORIDE INDUCED ALKALINE MEDIUM – AN ELECTROCHEMICAL APPROACH
(Elsevier, 2018-03-20) NusrathUnnisa C; Nirmala Devi G; Hemapriya V; Chitra S; Chung, Ill-Min; Kim, Seung-Hyun; Prabakaran M
As a motto of framing the strategies to minimise the deterioration in steel reinforced concrete structures as well as the fact that the work carried out with polymers are rare and scanty, polyesters namely Poly (Glycerol azealate) (PGAZ) and 4-(1-(4-methoxy phenyl) cyclo hexyl)phenyl 9-oxodecanoate (MPOD) were synthesised and evaluated for rebar corrosion in simulated concrete pore solution (SCP) for the first time at selected concentrations of 10, 100, 1000 ppm levels with an aid of electrochemical impedance and potentiodynamicpolarisation techniques. Nyquist plots favoured increased Rct values suggesting the formation of barrier. Tafel plots represented cathodic inhibition. The experimental datas were best fitted with Langmuir adsorption isotherm facilitating monolayer adsorption. Both the methods employed were in good agreement with each other favouring maximum inhibition efficiency of 71.81% for MPOD and minimum of 57.64% for PGAZ primarily due the difference in aromatic sites as revealed in mechanism.