Thermodynamic study of binary mixtures of toluene with ionic liquids, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide
Dorota Warmińska, Iwona Cichowska-Kopczyńska
Abstract
Densities, refractive indices and viscosities at 293.15, 298.15, 303.15, 308.15 and 313.15 K of binary mixtures of toluene with 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide have been measured over the miscible region at p = 0.1 MPa. From the experimental data, values of excess molar volume, excess thermal expansion, deviation in refractive index, deviation in viscosity and excess Gibbs energy of activation for viscous flow have been calculated. These properties have been fitted to the Redlich-Kister-type polynomial equation in order to analyse non-ideal behaviour of the studied mixtures. Moreover, partial and apparent molar volumes of toluene and ionic liquid in their binary systems have been calculated. Finally, the effects of temperature and cation of ionic liquid on the physicochemical properties were analysed and discussed in terms of intermolecular interactions occurring in the studied systems.