Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

To address the molecular interactions between ionic liquids (ILs) such as trimethylammonium acetate [(CH3)3NH][CH3COO] (TMAA), trimethylammonium hydrogen sulfate [(CH3)3NH][HSO4] (TMAS), trimethylammonium dihydrogen phosphate [(CH3)3NH][H2PO4] (TMAP) and triethylammonium dihydrogen phosphate [(CH3CH2)3NH][H2PO4] (TEAP) with N-methyl-2-pyrrolidone (NMP), density (rho), ultrasonic sound velocity (u), viscosity (mu) measurements have been performed across the entire concentration range and the wide temperature range from 298.15 to 313.15 K in steps of 5 K under ambient pressure. Further, on the basis of the measured properties, excess volumes (VE), isentropic compressibility deviations (Aes) and viscosity deviations (Ac) were obtained for all these systems under the same experimental conditions. The results are correlated by the Redlich.Kister type equation. The results are also analyzed on anion dependent phenomena and temperature influence on measured and derived properties of ILs with NMP mixtures. A qualitative analysis of molecular interactions between ILs and NMP is discussed in terms of the ion-dipole, ionpair interactions, and hydrogen bonding.