EVALUATION OF 1-BUTYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYL)AMIDE IONIC LIQUID AS NOVEL ABSORBENT OF 2,2,2-TRIFLUOROETHANOL OR ETHANOL REFRIGERANTS

In this work the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [bmim][NTf2], was evaluated as a novel absorbent of two alcohols, used as possible refrigerants to replace classical absorbent-refrigerant pairs: one of the alcohols is fluorinated (2,2,2-trifluoroethanol, TFE) and the other not (ethanol, EtOH). Two thermophysical properties were measured: mixing enthalpies at 298.15 K and 323.15 K and densities in the (288.15 - 333.15 K) temperature range, at atmospheric pressure. Thermal expansion coefficients and excess molar volumes were calculated from density data. Mixing enthalpies in both systems are positive, being smaller for [bmim][NTf2] + TFE than for [bmirn][NTf2] + EtOH, a difference that can be explained by the stronger interactions of the fluorinated alcohol with the ionic liquid.