Thermodynamic Properties of Tricyanomethanide-Based Ionic Liquids with Water: Experimental and Modelling

Measurement and Correlation of Density, Viscosity, and Surface Tension for Imidazolium Bromide Ionic Liquids [CnMIM]Br (n = 2, 3, 4) Aqueous Solutions

“…According to the working practice of absorption refrigeration or heat pump system, the cycle process of the working pairs mainly involves the transport, heat, and mass transfer and other physical processes, which are closely related to the density, viscosity, surface tension, and other basic physical properties of working pairs. So far, many research groups have carried out studies on the basic physical and chemical properties of binary or ternary systems composed of ionic liquids and other substances. − Królikowska et al synthesized four bromide-based ILs of [C 1 C 2 PIP]­Br, [C 1 C 4 PIP]­Br, [C 4 Py]­Br, and [N 2,2,2,4 ]Br and obtained the density, viscosity, and phase equilibrium data of their aqueous solutions with a differential scanning microcalorimetry technique. On the basis of experimental density data, the apparent molar volumes, limiting apparent molar volumes, limiting molar expansibilities, and isobaric thermal expansion coefficients were obtained.…”

Phase Equilibria, Thermodynamic Behavior, and Transport Properties of Aqueous Solutions of [BMPYR] Trifluoromethanesulfonate and [BMPYR] Tricyanomethanide

“…The data on IL density presented by us agree quite well with those from the literature, the differences being mostly within 0.0005 g·cm –3 and never exceeding 0.0010 g·cm –3 . The only outliers are the measurements of Gaciño et al for [BMPYR]­[OTF] using a high-pressure vibrating-tube instrument, which are about 0.0015 g·cm –3 higher, and those of Ayad et al , for [BMPYR]­[TCM] at near-ambient temperatures, which are almost 0.0020 g·cm –3 lower. Regarding the viscosity data, our measurement and all the literature data for [BMPYR]­[OTF] agree very well, within 5% and sometimes still better.…”

“…On the other hand, the values ln γ w ∞ in [BMPYR]­[TCM] of Liebert et al, being considerably lower, appear to be rather wrong. Furthermore, for the (water + [BMPYR]­[TCM]) system, Ayad et al . recently reported experimental vapor pressures at seven equidistant temperatures in the range T = (283.15 to 313.15) K. Unfortunately, their data turn out to be extremely scattered and spurious.…”

“…This is documented in Figure S12b, in which ∂ 2 ( G M / RT )/∂ x w 2 , the second derivative of the mixing Gibbs energy with respect to x w , as calculated from their model, is plotted at three temperatures. Ayad et al also determined the excess enthalpy and excess heat capacity for (water + [BMPYR]­[TCM]). Figure S13 compares their data with the predictions produced by our NRTL model.…”

“…Moreover, the data available originate from a number of rather particular studies dealing with individual properties, and those on phase equilibria are mostly isobaric, which hinders their exact thermodynamic treatment due to the convolution of the temperature and composition dependences. The only more comprehensive approach appeared in the recent study by Ayad et al who reported for (water + [BMPYR]­[TCM]) isothermal vapor–liquid equilibrium (VLE) data and data on three excess properties. Ironically, their VLE data are, however, of poor quality and misleading, as will be shown further below.…”