Jochen K. Lehmann

Excess Molar Volumes and Viscosities of Binary Mixtures of Methanol and the Ionic Liquid 4-Methyl-N-butylpyridinium Tetrafluoroborate at 25, 40, and 50°C

Experimental data of densities and viscosities are presented for the system 4-methyl-N-butylpyridinium tetrafluoroborate + methanol at 25, 40, and 50, 323.15 K and ambient pressure using a vibratage-tube densimeter and an Ubbelohde viscometer. Excess molar volumes VE and excess logarithm viscosities (ln η)E have been determined. VE is negative and (ln η)E positive over the entire mixture composition.

Enthalpies of Solution of Organic Solutes in the Ionic Liquids [Me3BuN][NTf2] and [EMIM][EtSO4]

Partial molar enthalpies of solution of 11 systems [Me3BuN][NTf2] + methanol, + ethanol, + 1-propanol, + 1-butanol, + benzene and [EMIM][EtSO4] + methanol, + ethanol, + 1-propanol, + 1-butanol, + CHCl3, + H2O have been measured at 298.15 K in the mole fraction range 1% to 25% of the solutes using a precision titration calorimeter (Thermal Activity Monitor 2277, Thermometrics). The experimental results have been extrapolated to infinite dilution of the solutes in the ionic liquids. The partial molar enthalpies of solution at infinite dilution Hi,∞E obtained by this method have been compared with values derived from the temperature dependence of the activity coefficients at infinite dilution γi,∞ which have been obtained by a gaschromatographic technique already published previously. Not for all systems studied agreement has been found within the experimental error limits of both methods indicating thermodynamic consistency of the results.