Viscosity of Methylbenzene in [Bmim][BF<sub>4</sub>] and [Bmim][PF<sub>6</sub>] Ionic Liquids

To well know the properties of ionic liquid mixtures, the viscosity of the binary mixtures containing the methylbenzene and imidazole ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] or 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim][PF6]) were measured. Within the temperature range from 298.15 K to 308.15 K, the viscosity of the four binary systems decreased sharply as the increase of temperature. The viscosity decreased slowly in the temperature range from 308.15 K to 338.15 K. The viscosity also decreased with decreasing of the mole fraction of ionic liquid. The viscosity of methylbenzene in the imidazole ionic liquids was in sequence: [Bmim][BF4] < [Bmim][PF6]. The experimental viscosity values had been correlated using the binary parameters of Vogel-Fulcher-Tamman equation.