Measurement and Correlation for Vapor Pressure and Excess Enthalpy of the New Working Pairs：Water/Ethanol/Methanol + Ionic Liquids 1-Ethyl-3-Methylimidazolium Diethylphosphate

Three binary solutions composed of ionic liquid (IL), 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM] [DEP]), and selected refrigerants (water, ethanol or methanol) were proposed as new working pairs for absorption heat pumps or absorption refrigerators. The vapor–liquid equilibrium (VLE) data were measured by a static method at different temperatures and at different ILs mole factions and correlated by the None-Random Two Liquids (NRTL) activity coefficient models, and the average relative deviation were less than 3.3%. The solutions showed strong negative deviation from the Raoult's Law and were able to absorb vapor of water, ethanol or methanol. The excess enthalpies were measured and correlated at 298.15 K and atmospheric pressure. The results indicated that the mixing of [EMIM] [DEP] with water, ethanol or methanol were exothermal. The proposed solutions were proved to possess one of the fundamental features that a working pair must have in absorption cycle.

Viscosity of Mixtures of α-Tocopherol Acetate + Mesitylene

The paper presents results of the share viscosity measurements performed as a function of temperature and concentration for mixtures of α-tocopherol acetate (vitamine E acetate) and mesitylene, two liquids of essentially different viscosity (four order of magnitude difference at 280 K). The viscosity/ temperature dependence for pure α-tocopherol acetate as well as for the mixtures studied can be well described with the Vogel-Fulcher-Tammann equation. The viscosities of the mixtures exhibit a strong negative deviation from the rule of additive dependence on concentration and for increasing temperature the maximum value of the deviation shows an exponential decreasing.

Molar Volumes in Molten NaBr, RbBr, NaBr-TlBr and RbBr-TlBr

Densities in molten NaBr and RbBr and molar volumes in their binary mixtures with TlBr are reported. The pyknometric method again gave slightly higher densities (0.1 - 0.2%) than previous Archimedean methods. In the mixtures the excess volume is no greater than ±1% but its variation with composition and temperature broadly resembles that in the MX-TIX systems reported previously. A relationship is apparent between the overall trend in the molar volume with composition and temperature and the variation in the Tl-X overlap by nmr. Together with the stoichiometry, this suggests that in the region of strong negative deviation coordination is high and localized orbital overlap low between cations and anions.