Ionic liquids partial molar volumes

Marcus Y (2012a) The standard partial molar volumes of ions in solution. Part 5. Ionic volumes in water at 125-200 °C. J. Phys. Chem. B 117 http //dx.doi/10.1021/jp212518t Marcus Y (2012b) Are ionic Stokes radii of any use J. Solution Chem in the press Marcus Y, Hefter G (1999) On the pressure and electric field dependencies of the relative permittivity of liquids. J Sol Chem 28 575-591 Marcus Y, Hefter G (2006) Ion pairing. Chem Rev 106 4585-4621... 

J. Kumelan, D. Tuma, G. Maurer, Partial molar volumes of selected gases in some ionic liquids. Fluid Phase Equilibria, 275, 132-144 (2009). 

For (12), it is assumed that the volume of the micellar phase is proportional to the tenside concentration and that the partial molar volume v remains constant. It is also assumed that the ionic mobility of the micellar phase does not change on taking up a solute (Mmc = constant). In contrast to high-performance liquid chromatography (HPLC), substances which have an infinitely high kp value, that is, which are completely dissolved in the micellar phase, can be detected. In this case, the sample molecule migrates with the mobility of the micelle. 

Sastry NV, Vaghela NM, Macwan PM (2013) Densities, excess molar and partial molar volumes for water + 1-butyl- or, 1-hexyl- or, l-octyl-3-methylimid-azolium halide room temperature ionic liquids at T = (298.15 and 308.15) K. J Mol Liq 180 12—18... 

One important solute is water, which is completely miscible in imidazolium salts with short alkyl side chains and hydrophilic anions such as d, but is only partially miscible with ionic liquids with longer side chains and less hydrophilic anions. Extraction into an aqueous phase is important for product recovery from an ionic liquid medium. Hanke and Lynden-BeU [143] used simulation to investigate thermodynamic properties and local structure in mixtures of water with [MMIM]Q and [MMIM][PF6] liquids. They found that the excess energy of solvation was negative for the chloride and positive for the [PF ]" liquid, as shown in Fig. 4.2-12. There is a similar difference in the molar volumes of mixing shown in Fig. 4.2-13. This is consistent with the perception of the [PFe]" anion as being more hydrophobic than the chloride anion. 

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