William Feld (Committee Member), David Grossie (Committee Member), Vladimir Katovic (Advisor)
Master of Science (MS)
Ionic liquids are of interest because of their electrochemical and thermal properties and their possible use as electrolytes in batteries. In this work five ionic liquids were synthesized. They consisted of a 1-alkyl-3-methylimidazolium (RMI+) cation, where the alkyl group was ethyl, propyl, butyl, pentyl, or hexyl, and a bis(tri-fluoromethylsulfonyl)imide (NTf2-)anion. The decomposition temperatures, melting points, conductivities, viscosities, densities, absorption and desorption of water, diffusion coefficients, and electrochemical properties were studied. It was found that these ionic liquids were thermally stable up to ~310 °C, and that EMINTf2 had a melting point at -18.26 °C. Conductivities decreased with increasing alkyl chain length on the imidazolium cation. The densities decreased with increasing chain length and with increasing temperature. Viscosities decreased with increasing temperature but increased with increasing alkyl chain length. Ionic liquids with longer alkyl chains absorbed less water from the atmosphere. The diffusion coefficient of ferrocene in ionic liquids decreased with increasing alkyl chain length. Electrochemical windows increased with increasing chain length, but decreased with an increase in water content. Comparisons of physicochemical and electrochemical properties of RMINTf2 ionic liquids were made with previously studied and analogous ionic liquids containing (RMI+) cation and the bis(pentafluoroethylsulfonyl)imide (Beti-) anion.
Department or Program
Department of Chemistry
Year Degree Awarded
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