Thermodynamic and thermophysical properties of the reference ionic liquid: 1-Hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide (including mixtures). Part 2. Critical evaluation and recommended property values (IUPAC Technical Report)

Abstract

This article is a product of IUPAC Project 2002-005-1-100 (Thermodynamics of ionic liquids, ionic liquid mixtures, and the development of standardized systems). Experimental results of thermodynamic, transport, and phase equilibrium studies made on a reference sample of the ionic liquid 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide are summarized, compared, and critically evaluated to provide recommended values with uncertainties for the properties measured. Properties measured included thermal properties (triple-point temperature, glass-transition temperature, enthalpy of fusion, heat capacities of condensed states), volumetric properties, speeds of sound, viscosities, electrolytic conductivities, relative permittivities, as well as properties for mixtures, such as gas solubilities (solubility pressures), solute activity coefficients at infinite dilution, and liquid-liquid equilibrium temperatures. Recommended values with uncertainties are provided for the properties studied experimentally. The effect of the presence of water on the property values is discussed.

Evidence of nanostructuration from the heat capacities of the 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid series

“…15 26 The relative atomic masses of the 11 elements have been presented as an interval, in the latest IUPAC technical report 2009. 27 Since the values reported in the IUPAC Commission in 2007 28 are within the presented interval, we choose to use the relative atomic masses recommended by the IUPAC report 2007 in this work.…”

Tris(2-ethylhexyl) trimellitate (TOTM) a potential reference fluid for high viscosity. Part I: Viscosity measurements at temperatures from (303 to 373) K and pressures up to 65 MPa, using a novel vibrating-wire instrument

“…In the meantime several kinds of liquids, like phthalates [7,21,27,28], sebacates [7,29], benzoates [21], squalane [6,9,21], perfluoropolyethers [5] and ionic liquids [30,31], have been suggested as possible candidates to be viscosity reference fluids at moderately high viscosity, as a replacement for DIDP.…”

“…However, a number of difficulties, mainly related to the experimental handling of the liquids, and the experimental procedures of the measurement techniques, have shown to be very difficult to achieve very accurate and even reproduce viscosity results of ionic liquid samples [33], due to the significant effects on viscosity caused by contaminations, mainly halides or water. It has been shown that contaminations of the order of hundreds or tens of parts per million can cause important effects on viscosity [30,31,33,34].…”

Thermodynamic and thermophysical properties of the reference ionic liquid: 1-Hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide (including mixtures). Part 1. Experimental methods and results (IUPAC Technical Report)

“…Mixture properties measured included gas solubility, solute activity coefficient at infinite dilution, excess volume, water solubility, and liquid-liquid equilibrium (LLE) temperatures. The critical evaluation of the data, along with recommended values including their combined expanded uncertainties, are published separately [2].…”

“…Measurements have been reported on samples other than the IUPAC sample, and those results are included in the critical evaluation [2], but are not discussed here except to comment on the suitability of the techniques.…”