Densities and viscosities of binary mixtures N,N-dimethyl-N-(3-sulfopropyl)cyclohexylammonium tosylate with water and methanol at TÂ =Â (303.15 to 328.15) K

Densities, ρ and viscosities, η of N,N-dimethyl-N-(3-sulfopropyl)cyclohexylammo-nium tosylate ([CyN1,1PrSO3H][Tos]) with water and methanol were measured, at temperatures from 303.15 K to 328.15 K with 5 K interval and 0.1013 MPa, as a function of [CyN1,1PrSO3H][Tos] molality (or mass fraction). The isobaric thermal expansion coefficient, molecular volume, standard molar entropy, and lattice energy of the pure IL were obtained based on the density data of pure IL. The apparent molar volume, Vφ, infinite dilution apparent molar expansibility, Eφ∞ and energy barrier, E were calculated from the experimental data. The Redlich-Mayer equation was used to evaluate infinite dilution apparent molar volume, Vφ∞. In addition, viscosities can be described satisfactorily by Vogel-Fulcher-Tammann (VFT) equation. The Vφ∞ values of the IL in water are higher than those in methanol, which suggests that the ion-solvent interactions for [CyN1,1PrSO3H][Tos] + water binary system are stronger than those for [CyN1,1PrSO3H][Tos] + methanol. And the energy barrier values decrease with the drop of IL mass fraction in both systems, indicating that the viscosity changes of binary mixtures are more sensitive to the temperature at high composition of the IL.