Ionic Conductivities of Binary Mixtures Containing Pyridinium-Based Ionic Liquids and Alkanols

Abstract

In this study, we have determined ionic conductivities of six binary systems composed of an ionic liquid (1-butylpyridinium tetrafluoroborate, 1-butyl-3methylpyridinium tetrafluoroborate, or 1-butyl-4methylpyridinium tetrafluoroborate) and a short chain alkanol (methanol or ethanol) at four temperatures, T = (293.15, 303.15, 313.15, and 323.15) K. The ionic conductivity data have been correlated using both an empirical equation and the Vogel–Tamman–Fulcher equation. We also have compared the behavior of different mixtures, paying special attention to the influence of methyl group in the pyridine ring and the effect of both alkanols in the mixtures. Ionic conductivities of all the mixtures are bigger than those of the pure components and present a maximum at small mole fractions of the ionic liquid. Moreover, conductivity values are bigger for the binary mixtures containing methanol instead or ethanol. Finally, the relationship between viscosity and ionic conductivity from Waldeńs rule has provided a measurement of the ionicity of the mixtures.