Electric impedance of aqueous KCl and NaCl solutions: Salt concentration dependence on components of the equivalent electric circuit
| Autor: | H. Mukai, P. R. G. Fernandes, Lisandra Ferreira de Lima, Admilson Lopes Vieira, Cid Marcos Gonçalves Andrade |
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| Rok vydání: | 2017 |
| Předmět: |
Permittivity
Aqueous solution Constant phase element Chemistry Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics Electrical contacts 0104 chemical sciences Electronic Optical and Magnetic Materials Dielectric spectroscopy Electrical resistivity and conductivity Materials Chemistry Equivalent circuit Physical and Theoretical Chemistry 0210 nano-technology Electrical impedance Spectroscopy |
| Zdroj: | Journal of Molecular Liquids. 241:530-539 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2017.06.069 |
| Popis: | In this work, we report an investigation of electrical impedance behavior of dilute aqueous solutions of potassium chloride KCl(aq) and sodium chloride NaCl(aq) (0.1 to 0.7 mMol/L) in the frequencies ranging from 10.0 mHz to 10.0 MHz. The real and imaginary parts of the complex electrical impedance are obtained by using the Electrical Impedance Spectroscopy (EIS) technique. The amplitude of the AC applied voltage is 20.0 mV. The complex electrical impedance results of the solutions are modeled by using an equivalent electrical circuit with a good agreement with the experimental data. This proposed circuit is composed by three sections connected in series. The first one is composed by a parallel RC associated with bulk effects, the second section is composed by a capacitor in parallel to a constant phase element (CPE) associated with the electric double-layer and the last one section composed by a resistance in series with an inductor associated with resistances of the electrical contacts and with parasites inductances of the connected cables. The components of the equivalent circuit are investigated as a function of salt concentration. As additional results, the electrical conductivity and complex permittivity of the samples are calculated and the electrical properties of the solutions are investigated as a function of kind of cations. For both K+ and Na+ cations, the bulk effects are well described by Debye model. However, the electric double-layer shows a higher resistance associated with cation Na+ than that associated to cation K+. Even for very low concentrations of salt, for both salts, it was observed an inverse relationship between impedance and salt concentration. |
| Databáze: | OpenAIRE |
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