Dyachenko Denis Igorevich, Postgraduate student, assistant, sub-department of forensic and physical materials, Volgograd State University (100 Universitetsky avenue, Volgograd, Russia), firstname.lastname@example.org
Fomichev Valery Tarasovich, Professor, head of sub-department of general and applied chemistry, Volgograd State University of Architecture and Construction (1 Akademicheskaya street, Volgograd, Russia), email@example.com
Background. Ionic liquids can serve as an environmentally safe alternative to highly toxic and costly solvents in electrochemistry. In this paper the authors analyze a number of physical and electrochemical characteristics of ionic liquids based on choline chloride.
Materials and methods. The research was conducted on the basis of ionic liquids with choline chloride, urea, ethylene glycol and glycerol. The authors defined their physical characteristics such as refractive index, viscosity, density and pH value. To study electrochemical characteristics the researchers applied the method of cyclic voltammetry. Calculation of activation energy of conductivity was based on the temperature dependence of the electrical conductivity of solutions and application of the model Vogel – Fulcher – Tamman to study ionic liquids.
Results. This paper presents investigations of a series of physical characteristics of ionic liquids based on choline chloride, such as refractive index, viscosity, density and pH value. The authors analyzed stationary cyclic voltammetric curves of the ionic liquids studied at various temperatures. On the basis of the temperature dependence of conductivity and models of Vogel – Fulcher – Tamman at the temperature range 298 ÷ 323 K the researchers performed calculations of activation energy of conductivity of ionic liquids based on choline chloride.
Conclusions. The studies explain the non-linear nature of the temperature dependence of the solutions’ electrical conductivity. The applicability of the model Vogel – Fulcher – Tamman for ionic liquids containing small, symmetrical cations with low molecular weight are presented. On the basis of the analysis of stationary circular current-voltage curves the authors have confirmed an assumption of the diffusion stage slowness.
choline chloride, eutectic mixture, ionic liquids, electrolytes for “green” chemistry, model Vogel – Fulcher – Tamman
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