Search

The influence of levetiracetam (LV) on the inhibition of copper corrosion in 0.5 M HNO3 solutions was studied using electrochemical techniques (potentiodynamic polarization and electrochemical impedance spectroscopy), weight loss as well as thermodynamic calculations to explore the adsorption mechanism of LV. The inhibition efficiency (IE%) was found to increase with increasing the concentration of the inhibitor and with decreasing the temperature. The maximum inhibition efficiency of 94.99% was observed in the presence of 300 ppm LV. The inhibition action of the compound LV was explained in terms of adsorption on the copper surface. The adsorption process follows Langmuir isotherm. Kinetic as well as thermodynamic parameters (activation energy, enthalpy of activation, entropy of activation and free energy of adsorption) were calculated and discussed. Electrochemical impedance spectroscopic technique (EIS) exhibit one capacitive loop indicating that, the corrosion reaction is controlled by the charge transfer process. Polarization measurements showed that the inhibitor is of mixed type. DFT calculations of LV were also studied to determine interactions with the copper surface. Further, the surface analysis via scanning electron microscope (SEM) and atomic force microscope (AFM) shows a significant improvement on the surface morphology of the copper plate. Results obtained from the different methods are in good agreement. The investigation revealed the possible application of LV drug as an environmentally friendly inhibitor for corrosion prevention under specific conditions.

The adsorption effect of esomeprazole (ESP) and lansoprazole (LP) on corrosion behavior of copper in 1 M HNO3 solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The experimental results indicate that both ESP and LP inhibited the corrosion of copper in nitric acid solution and the inhibition efficiency increased as the concentration of the compounds increased. EIS measurements confirmed that the charge transfer resistance increases on increasing the inhibitor concentration. Polarization measurements showed that the inhibitors are of mixed type. From the weight loss measurements, the inhibition efficiency of the inhibitors was found to vary with concentration, immersion time, and temperature. The adsorption of inhibitors on the copper surface follows Langmuir isotherm. The surface morphology was examined by scanning electron microscope and atomic force microscope. Further, the computational calculations are perfor...

The inhibition performance of atenolol on mild steel in 1 M hydrochloric acid solution was studied by weight loss and electrochemical methods. The results show the inhibition efficiency was found to increase with increasing the concentration of the inhibitor from 50 to 300 ppm. The maximum inhibition efficiency 93.8% was observed in the presence of 300 ppm inhibitor (in case of potentiodynamic polarization). The inhibition action of atenolol was explained in terms of adsorption on the mild steel surface. The adsorption process follows Langmuir isotherm via physical adsorption. Electrochemical Impedance spectroscopic technique (EIS) exhibits one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. Polarization measurements showed that the inhibitor is of a mixed type. The results obtained from the different methods are in good agreement. The surface morphologies of mild steel were examined by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM). Further, the computational calculations are performed to find a relation between their electronic and structural properties.

The effect of Sodium 2-oxo-3-(3-oxo-1-phenylbutyl)-2H-chromen-4-olate against the corrosion of mild steel in 1 M HCl solution was investigated using weight loss and electrochemical methods. The results show that inhibition efficiency increases with increased inhibitor concentration from 50 ppm to 300 ppm. The adsorption of inhibitor obeyed Langmuir adsorption isotherm model and the thermodynamic parameters are also calculated. Polarization measurements showed that the used inhibitor is mixed type. The surface morphologies were examined by scanning electron microscope and atomic force microscope. It confirms the formation of a compact protective film of inhibitor on the metal surface thereby inhibiting the corrosion. FT-IR spectroscopy could be involved in determining the interaction of inhibitor with the metal surface. Further, the computational calculations are performed to find a relation between their electronic and structural properties. Computational and experimental results are in good agreement.

The effect of commercially available pharmaceutically active compound amikacin disulfate (AMK) against the corrosion of copper in 1 M HNO3 solution was investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), and weight loss techniques. The results show that inhibition efficiency (IE %) increases with increasing inhibitor concentration from 0.1 to 1.0 mM. Increasing the temperature increased the corrosion rate, and results decreased the inhibition efficiency. The adsorption of inhibitor obeyed Langmuir adsorption isotherm model via physisorption mechanism. EIS technique exhibits one capacitive loop, indicating that the corrosion reaction is controlled by charge transfer process. Polarization measurements showed that the AMK is mixed-type inhibitor. The surface morphologies were studied by scanning electron microscopy and atomic force microscopic techniques. The corrosion mechanism were explained by Fourier transform infrared spectroscopy.

The effect of newly synthesized 6-hydroxy-5,7-diphenyl-1,3-diazaadamantane (HDDA) and 5,7-diphenyl-1,3-diazaadamantan-6-one (DDA) against the corrosion of copper in 1 M HNO3 solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. These measurements show that the inhibition efficiency (IE %) obtained by these compounds increased by increasing their concentrations, and maximum IE % to 90.84 % for HDDA and 89.87 % for DDA were found at 300 ppm. Data obtained from EIS studies were analyzed by an equivalent circuit model. EIS plots indicated that the inhibitor performance depends on the adsorption of the molecules on the metal surface. Polarization measurements showed that both HDDA and DDA are mixed-type but predominantly cathodic in 1 M HNO3 solution. The adsorption of inhibitors on the copper surface from the nitric acid follows the Langmuir adsorption isotherm with a negative value of free energy, and these values indicated that adsorption of both HDDA and DDA molecules adsorbs physically on the copper surface. The surface morphology was examined by scanning electron microscope and atomic force microscope. Further, theoretical calculations were carried out and relationships between computed parameters and experimental IE % were discussed. All the results confirmed that e HDDA showed better efficiency in 1 M HNO3 compared to DDA.

The effect of a pharmaceutically active compound esomeprazole (IUPAC name: [S]-5-methoxy-2-[(4-methoxy-3,5-dimethylpyridin-2-yl)methylsulfinyl]-3H-benzoimidazole) on the corrosion of mild steel in 0.5 M HCl solution has been investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, adsorption isotherm, and scanning electron microscope (SEM). Inhibition efficiencies of esomeprazole increased as the concentration of esomeprazole increases, but decreased with increases in temperature, immersion period, and acid concentration. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the metal surface. The Langmuir adsorption isotherm was found to be the best isotherm that described the adsorption characteristics of the inhibitor. Also, the activation and thermodynamic parameters of dissolution and adsorption were calculated and discussed. Further, the SEM analysis confirms the formation of an adsorbed protective film on the mild steel surface. Based on all these results, esomeprazole is found to inhibit the corrosion of mild steel in 0.5 M HCl solution, and a plausible mechanism of corrosion inhibition is proposed.

The inhibition of the corrosion of mild steel in 1 M H2SO4 solution by the pharmaceutically active compound esomeprazole (ESP) has been investigated by using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy measurements. The effect of temperature on the corrosion behavior with the addition of different concentrations of ESP was studied in the temperature range of 30–60°C. Results obtained revealed that the inhibition efficiency increased with the increase in concentration of the inhibitor but decreased with the increase in temperature. The addition of KI increased the inhibition of ESP to a considerable extent. The experimental results suggest that the presence of iodide ions in the solution stabilized the adsorption of the ESP molecule on the mild steel surface, thereby improving the inhibition efficiency. Polarization curves indicated that the ESP belonged to a mixed-type inhibitor. Adsorption of the inhibitor on the mild steel surface is found to obey the Langmuir adsorption isotherm. Some thermodynamic functions of dissolution and adsorption processes were also determined. Surface analysis via scanning electron microscope (SEM) and atomic force microscope (AFM) shows a significant improvement in the surface morphology of the mild steel plate.

The inhibiting action against the corrosion of mild steel by ondansetron hydrochloride (ODSH) drug was studied, using various studies such as weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization measurement, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), FT-IR spectroscopy and reactivity of molecule is studied using quantum chemical calculation. The result shows that ondansetron hydrochloride (ODSH) gives better inhibition on mild steel. The value of activation energy (Ea) and various thermodynamic parameters such as adsorption equilibrium constant (Kads), free energy of adsorption (ΔG0ads), adsorption enthalpy (ΔHads) and adsorption entropy (ΔSads) was calculated and discussed. The adsorption of ODSH on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurement reveals that ODSH acts as a mixed-type inhibitor. Electrochemical impedance spectroscopy (EIS) spectra exhibit one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. SEM, EDX, AFM, FT-IR conforms to the protective film formation. Quantum chemical calculation was calculated and discussed, and it supports the results.

Aromatic polyamides and polythioamides with pendent chlorobenzylidine rings were synthesized through direct polycondenzation of 2-(p-chlorobenzalimino) terephthalic acid with the diamines 4,4′-oxidianiline (1a), 4,4′-methylenediamide (1b), 4,4′-diaminodiphenyl sulfone (1c), and thioamines 4,4′-(bisthiourea) diphenyl ether (3a), 4,4′-(bisthiourea) diphenyl methane (3b), 4,4′-(bisthiourea) diphenyl sulfone (3c), respectively, in DMF using P(OPh)3/pyridine. The polymers were precipitated using water as nonsolvent. FTIR and 1H-NMR spectroscopic analysis was used to characterize the monomers and polymers. Representative polyamides and polythioamides were used for the removal of heavy metal ions such as Pb(II), Cd(II), Cu(II), and Cr(III) from aqueous solutions. The effects of pH, contact time, and initial concentration on the uptake of metal ions have been investigated. The adsorption capacities under competitive conditions were in the order Pb (II) > Cu (II) > Cr (III) > Cd (II). The adsorbed ions were eluted by treatment with 2N HCl, and the activities of the polymers are retained after fourth regeneration. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The influence of levetiracetam (LV) on the inhibition of copper corrosion in 0.5 M HNO 3 solutions was studied using electrochemical techniques (potentiodynamic polarization and electrochemical impedance spectroscopy), weight loss as well as thermodynamic calculations to explore the adsorption mechanism of LV. The inhibition efficiency (IE%) was found to increase with increasing the concentration of the inhibitor and with decreasing the temperature. The maximum inhibition efficiency of 94.99% was observed in the presence of 300 ppm LV. The inhibition action of the compound LV was explained in terms of adsorption on the copper surface. The adsorption process follows Langmuir isotherm. Kinetic as well as thermodynamic parameters (activation energy, enthalpy of activation, entropy of activation and free energy of adsorption) were calculated and discussed. Electrochemical impedance spectroscopic technique (EIS) exhibit one capacitive loop indicating that, the corrosion reaction is controlled by the charge transfer process. Polarization measurements showed that the inhibitor is of mixed type. DFT calculations of LV were also studied to determine interactions with the copper surface. Further, the surface analysis via scanning electron microscope (SEM) and atomic force microscope (AFM) shows a significant improvement on the surface morphology of the copper plate. Results obtained from the different methods are in good agreement. The investigation revealed the possible application of LV drug as an environmentally friendly inhibitor for corrosion prevention under specific conditions.