Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with ethanol at T=(293.15-313.15)K

In this study, density, speed of sound and viscosity of binary mixtures of ionic liquids+ethanol have been measured as a function of composition at T=(293.15-313.15)K and atmospheric pressure. The ionic liquids studied were: {n-butylammonium acetate (N4Ace), n-butylammonium propanoate (N4Pro), n-butylammonium hexanoate (N4Hex), and n-butylammonium decanoate (N4Dec)}. Excess molar volume, VmE</mml:msubsup>, deviation in isentropic compressibility, S, deviation in viscosity, , and excess Gibbs energy of activation of viscous flow, GE, were obtained from experimental results and correlated with the Redlich-Kister polynomial equation. Ionic liquids were synthesized and characterized using H-1-NMR, C-13-NMR and FTIR spectroscopy techniques. For all systems studied, the values of VmE, <mml:msub>S and were negative over the entire composition range, whereas GE values were positive over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.