Dr Vasily Artemov, Prokhorov General Physics Institute, Russia. Part of the Physical Seminar Series
Full title and abstract:- Space-time dynamics of charges in aqueous electrolyte solutions from broadband dielectric spectroscopy data V.G. Artemov Prokhorov General Physics Institute of Russian academy of sciences, Moscow, Russia Aqueous solutions serves as a medium for charge transport in a variety of biological and industrial systems. However, its properties on the atomic-molecular level are not fully understood. According to the Arrhenius model, the electric conductivity of aqueous solutions is realized by the ions of electrolyte. Water is considered to be a chemically inactive environmental media. This view being tested on the static conductivity of aqueous solutions turns out to be untenable for the dynamic conductivity in the GHz and THz regions. Here we discuss a conceptually new model of the atomic-molecular motion in aqueous electrolyte solutions in relation to the broadband dielectric spectrum. We propose a model that gives a self-consistent description of dielectric permittivity, dc-conductivity and microwave absorption simultaneously without considering solute ions [1]. Within the framework of the model, water has a high concentration of the intrinsic H3O+ and OH− ions [2]. This ions masked in the dc-conductivity of pure water by the electrophoretic effect. A local chemical interaction between the solute and the water intrinsic ions break down the electrophoretic effect and ‘activate’ the dc-conductivity [3]. Details of the model and its practical consequences will be discussed. [1] V.G. Artemov, A.A. Volkov, N.N. Sysoev, A.A. Volkov, Conductivity of aqueous HCl, NaOH and NaCl solutions: Is water just a substrate? // Eur. Phys. Lett., – 2015. – 109. – P. 26002. [2] A.A. Volkov, V.G. Artemov and A.V. Pronin, A Radically New Suggestion about the Electrodynamics of Water: Can the pH Index and the Debye Relaxation be of a Common Origin? // Eur. Phys. Lett., – 2014. – 106. – P. 46004. [3] A.A. Volkov, V.G. Artemov, A.A. Volkov (Jr.), N.N. Sysoev, Possible mechanism of molecular motion in liquid water from dielectric spectroscopy data // Journal of Molecular Liquids, – 2017. – 248. – P. 564-568.