PREDICTION OF VAPOR PRESSURE OF [C6MIM][NTF2] AND [C8MIM][NTF2] USING CPA EQUATION OF STATE.

Associating systems are one of non-ideal systems for which specific equations are required to take into account the association effects. The Cubic Plus Association (CPA) equation of state (EoS) has been proposed to combine a cubic EoS expression with an association term, derived from the Wertheim theory as applied in the Statistical Associating Fluid Theory (SAFT) for taking into account the hydrogen bond interactions. In this study 2B association scheme for ionic liquids 1- hexyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([C6mim][NTf2]) and 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([C8mim][NTf2]) is used. The pure component parameters are obtained by fitting the predictions of the model to experimental vapor pressure and liquid density data. Two sets of parameters provide a good description of experimental vapor pressures.