Search for content and authors

Thermodynamic Phase Behavior of Ionic Liquids

Urszula M. Domańska-Żelazna 

Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, Warszawa 00-664, Poland


The solid-liquid and liquid-liquid phase equilibria of ionic liquids (ILs) basing on alkyl-(2-hydroxyethyl)-dimethyl-ammoniumcation [Cn] and different anions [Br-, or N(CN)2-, or PF6-, or BF4-, or N(CF3SO2)2-] [1] and 1-alkoxymethyl- 3-methyl-imidazolium, ([CnH2n+1OCH2mim]) or 1,3-dialkoxymethyl-imidazolium ([(CnH2n+1OCH2)2im]) cations with different anions {BF4-, N(CF3SO2)2-} [2] have been measured. The determination of the IL - solvent interaction of these salts and alkyl-methyl-imidazolium cations with {[CH3SO4-], or [OcSO4-], or [MDEGSO4-], or [TOS-]} anions via the solubility measurements, or excess molar volumes or activity coefficients at infinite dilution measurements have been performed. The influence of high pressure up to 600MPa on IL's SLE has been also investigated. These salts mainly exhibit simple eutectic systems with immiscibility in the liquid phase with upper critical solution temperatures (UCST).

The SLE and LLE curves were correlated by means of the different GEx models utilizing parameters derived from the SLE or LLE. The root-mean-square deviations of the solubility temperatures for all calculated data depend on the particular system and the equation used. The (liquid + liquid) phase equilibria was predicted for many systems with COSMO-RS model.

Due to the fascinating physico-chemical properties of these ionic liquids, they seem to be significant in development of new technologies.


[1] U. Domańska, R. Bogel-Łukasik, J. Phys. Chem. B 2005, 109, 12124.

[2] U. Domańska, A. Marciniak, J. Chem. Thermodyn. 2005, 37, 577.


Legal notice
  • Legal notice:

Presentation: oral at 18th Conference on Physical Organic Chemistry, Symposium 1, by Urszula M. Domańska-Żelazna
See On-line Journal of 18th Conference on Physical Organic Chemistry

Submitted: 2006-05-22 12:52
Revised:   2009-06-07 00:44