Journal of Physical Chemistry B, Vol.118, No.22, 5971-5982, 2014
Thermophysical Properties of Aqueous Solution of Ammonium-Based Ionic Liquids
Experimental densities (rho), ultrasonic sound velocities (u), viscosities (eta), and refractive indices (eta(D)) of binary mixtures of ammonium-based ionic liquids (ILs) such as diethylammonium acetate (DEAA) [(CH3CH2)(2)NH][CH3COO], triethylammonium acetate (TEAA) [(CH3CH2)(3)NH][CH3COO], diethylammonium hydrogen sulfate (DEAS) [(CH3CH2)(2)NH][HSO4], triethylammonium hydrogen sulfate (TEAS) [(CH3CH2)(3)NH][HSO4], trimethylammonium acetate (TMAA) [(CH3)(3)NH][CH3COO], and trimethylammonium hydrogen sulfate (TMAS) [(CH3)(3)NH][HSO4] with water are reported over the wide composition range at 25 degrees C under atmospheric pressure. The excess molar volumes (V-E), deviation in isentropic compressibilities (Delta K-s), deviation in viscosities (Delta eta) and deviation in refractive indices (Delta(nD)) are calculated from experimental values and are correlated by Redlich-Kister polynomial equations. The V-E and Delta K-s values for the aforesaid systems are negative over the entire composition range while the Delta eta and Delta(nD) values are positive under the same experimental conditions. The intermolecular interactions and structural effects were analyzed on the basis of measured and derived properties. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions and hydrogen bonding between ILs and water. Furthermore, the hydrogen bonding features between ILs with water were analyzed by using a molecular modeling program with the help of HyperChem7.