Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Origin of Capacity Fading in Nano-Sized Co3O4 Electrodes: Electrochemical Impedance Spectroscopy Study
Electrochemical impedance spectroscopy (EIS) has been applied to study the water uptake for four primer paint films J1 - J4 on carbon steel surfaces exposed to seawater. Based on the Brasher-Kingsbury equation, the water uptake was estimated from CC values calculated by both EIS data treatments: one from the high frequency Nyquist semicircle and the other by using Fit and Simulation software.
The electrophoretic deposition (EPD) method was adopted for a fabrication of nanocomposite layers composed of ZnO particles covered by the polythiopene shell in a reduced state. This composite was prepared by oxidative polymerization of thiophene monomer with iron (III) chloride as a catalyst in the presence of ZnO particles. After polymerization, polythiophene in oxidized form was reduced by the extraction in methanol. Electrochemical properties of the obtained composite were measured by cyclic voltammetry and electrochemical impedance spectroscopy.
The conducting polymer poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-3-acetic acid-1,4- naphthoquinone) with electroactive quinone group was investigated by Electrochemical Impedance Spectroscopy (EIS) in aqueous medium. The evaluations of parameters of equivalent circuit in term of applied potential were considered. The simulated EIS data presented a good agreement with the results obtained by other electrochemical methods.
Corrosion is expensive and can be hazardous. It is costly to replace and repair
equipment, structures, and other industrial items that have been damaged as a result
of corrosion. In order to understand the mechanisms of corrosion, solve the corrosion
problems, and improve the corrosion resistance of materials, the use of modern
evaluation and protection techniques is essential. Therefore no significant progress can
be achieved in this area without the use of modern evaluation methods combined with
This study is focused on the synthesis of a polyindole doped by indole-3 butyric acid (PI-IBA). IR analyze indicated that the linkage positions of indole involves the position 2 and 3 of the monomer and the insertion of IBA in the polymer backbone. Polyindole IBA doped was incorporated into epoxy resin for protection anticorrosion of carbon steel. The electrochemical impedance measurements show a significantly improvement of protective properties in presence of PI-IBA in comparison with pure epoxy and epoxy containing polyindole coating.
Polyaniline has been electrochemically formed on stainless steel in sulphuric acid 0.5 N with and without KClO3. The CV spectrum style and the peak characteristic parameters, as peak potential Ep, peak current Jp, peak charges quantity Qp, then have been analyzed under a consideration of the effect of KClO3. The resistance of the PANi films was studied using electrochemical impedance measurement. It has been found that KClO3 has affected the PANi morphology much more than the CV spectrum.
Corrosion inhibition of organic clay nanofil5 in NaCl 0.1 M solution was studied by polarization curves and electrochemical impedance spectroscopy. The clay concentrations studied were between 1 g/l and 5 g/l. The clay nanofil5 plays both anodic and cathodic corrosion inhibition. The corrosion inhibition of clay nanofil5 depends on the concentration. The results obtained by two methods were in good agreement and showed that the highest inhibition efficiency was obtained with the nanofil5 concentration of 3 g/l.
Effect of sodium nitrite on the carbon steel corrosion inhibition in the aerated neutral (pH 7) and alkaline (pH 11) water solutions at temperatures from 30o C to 140o C has been investigated by mass loss, potentiodynamic polarization and electrochemical impedance spectroscopy methods. Sodium nitrite was added in concentrations: 200, 350, 500, 750, 1000, 1500 and 2000 ppm by mass.
An ion-selective electrode (ISE) is an example of an electrochemical sensor utilizing the principle of potentiometry, or measurement of the cell potential (i.e., ISE against a standard reference electrode) at near-zero current. Under these conditions, the boundary potential at the ISE–solution interface is governed by the laws of electrochemical thermodynamics or is compliant with the famous Nernst equation.
Chemical structure of -aminonaphthalene (ANa) allows to deal with its electrochemical polymerisation, analogously as for aniline. To determine the oxidation potentials of ANa, the polymerisation has been realised on Pt electrode using cyclic polarisation. It was found that in sulphuric acid 0.5 M the first oxidation starts at 620 mV/SCE with the peak potential at 760 mV, and the second oxidation at 890 mV/SCE with the peak potential at 1230 mV. The PANa film development decreases the current peaks meaning a reduction of polymerisation rate.