title: Excess enthalpies of mixing, effect of temperature and composition on the density, and viscosity and thermodynamic properties of binary systems of {ammonium-based ionic liquid + alkanediol}.
abstract: In the present work the excess enthalpies of butyltrimethylammonium bis(trifluoromethyl-sulfonyl)imide, [N1114][NTf2], with 1,2-propanediol, or 1,2-butanediol, or 2,3-butanediol have been measured at T = 298.15 K. Additionally, the density, ρ, and dynamic viscosity, η, for binary solutions containing ionic liquids (ILs) and alkanedioles, {butyltrimethylammonium bis(trifluoromethyl-sulfonyl)imide, [N1114][NTf2], + 1,2-propanediol, 1,2-butanediol, 2,3-butanediol} and {(2-hydroxyethyl)trimethylammonium bis(trifluoro-methylsulfonyl)imide, [N1112OH][NTf2], + 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol}, at wide temperature and composition ranges at ambient pressure have been investigated. From experimental values of the density, ρ, and dynamic viscosity, η, the excess molar volumes, V(E), and dynamic viscosity deviations, Δη, were calculated and correlated using the Redlich-Kister polynomial equation. The temperature dependence of density and viscosity for the tested binary systems was described by an empirical second-order polynomial and by the Vogel-Fucher-Tammann equation, respectively. The variation of density and viscosity as a function of composition has been described by the polynomial correlations. Comparison of the experimental results for the binary mixtures tested in this work allows us to determine the influence of alkanediol carbon chain length, the position of the hydroxyl group in the alcohol, and the influence of the structure of the cation of the ionic liquid on the presented properties.
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology , Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Domańska
authors.forename: Paulina
authors.initials: P
authors.lastname: Papis
authors.forename: Jerzy
authors.initials: J
authors.lastname: Szydłowski
authors.forename: Marta
authors.initials: M
authors.lastname: Królikowska
authors.forename: Marek
authors.initials: M
authors.lastname: Królikowski