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Phase equilibria and modeling of ammonium ionic liquid, C2NTf2, solutions
Urszula Domańska1, Andrzej Marciniak, Marek Królikowski
1Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. ula@ch.pw.edu.pl
The Journal of Physical Chemistry. B
|January 9, 2008
Summary
A new ionic liquid, ethyl(2-hydroxyethyl)dimethylammonium bis(trifluomethylsulfonyl)imide (C2NTf2), was synthesized and characterized. Its phase equilibria with various solvents were measured and correlated, providing insights into its behavior in different mixtures.
Area of Science:
- Materials Science
- Physical Chemistry
- Chemical Engineering
Background:
- Ionic liquids (ILs) are versatile solvents with tunable properties.
- Quaternary ammonium ionic liquids are a significant class of ILs with diverse applications.
- Understanding the phase behavior of ILs is crucial for their practical implementation.
Purpose of the Study:
- To synthesize and characterize a novel quaternary ammonium ionic liquid, ethyl(2-hydroxyethyl)dimethylammonium bis(trifluomethylsulfonyl)imide (C2NTf2).
- To determine the thermophysical properties and phase equilibria of C2NTf2 with various organic solvents and water.
- To correlate the phase equilibrium data using the nonrandom two-liquid (NRTL) equation.
Main Methods:
- Synthesis of C2NTf2 from N,N-dimethylethanolamine.
- Characterization using Nuclear Magnetic Resonance (NMR) spectroscopy.
- Thermophysical property determination via Differential Scanning Calorimetry (DSC).
- Measurement of solid-liquid and liquid-liquid phase equilibria using a dynamic method.
- Correlation of phase equilibrium data with the NRTL equation.
Main Results:
- Successful synthesis and characterization of the novel C2NTf2 ionic liquid.
- Comprehensive data on melting point, phase transitions, glass transition, decomposition temperature, and water content.
- Extensive solid-liquid and liquid-liquid phase equilibrium data for C2NTf2 with water, alcohols, hydrocarbons, DMSO, and THF across a wide temperature range (230–430 K).
- Accurate correlation of phase equilibria using temperature-dependent NRTL parameters.
- Calculation of a negative partition coefficient (log P) for C2NTf2 in the octan-1-ol/water system.
Conclusions:
- The novel C2NTf2 ionic liquid exhibits distinct thermophysical properties.
- The measured phase equilibria provide valuable data for designing separation processes involving C2NTf2.
- The NRTL model effectively describes the phase behavior of C2NTf2 in binary mixtures.
- The calculated partition coefficient suggests specific solubility characteristics relevant to extraction applications.
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