Density and viscosity of three (2,2,2-trifluoroethanol+1-butyl-3-methylimidazolium) ionic liquid binary systems

Densities and viscosities were determined for binary mixtures of 2,2,2-trifluoroethanol (TFE) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) or 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([bmim][NTf2]) over the entire range of composition. The experimental measurements were carried out at temperatures ranging from 278.15 K to 333.15 K, at atmospheric pressure. The densities and viscosities of the pure ionic liquids and their mixtures with TFE were described successfully by an empirical third-order polynomial and by the Vogel-Fulcher-Tammann equation, respectively. In addition, excess molar volumes and viscosity deviations were determined from densities and viscosities of mixtures, respectively, and fitted by using the Redlich-Kister equation. (C) 2013 Elsevier Ltd. All rights reserved.