Related Experiment Video
Updated: Mar 19, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Comparing two tetraalkylammonium ionic liquids. II. Phase transitions
Thamires A Lima1, Vitor H Paschoal1, Luiz F O Faria1
1Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970 São Paulo, SP, Brazil.
Phase transitions in two ionic liquids were studied. Both exhibit glass transitions under high pressure, with structural changes observed during thermal events and conformational shifts in molecular structures.
Area of Science:
- Materials Science
- Physical Chemistry
- Condensed Matter Physics
Background:
- Ionic liquids (ILs) are salts that are liquid at ambient temperatures.
- Understanding their phase transitions is crucial for applications in various fields.
- Bis(trifluoromethanesulfonyl)imide-based ILs are widely studied due to their unique properties.
Purpose of the Study:
- To investigate the phase transitions of n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide ([N1114][NTf2]) and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide ([N1444][NTf2]).
- To explore the influence of temperature and high pressure on the structural behavior of these ILs.
Main Methods:
- Differential scanning calorimetry (DSC) for thermal analysis.
- X-ray diffraction (XRD) for structural characterization.
- Raman spectroscopy (including high-pressure studies with a diamond anvil cell) for molecular-level insights.
Main Results:
- [N1444][NTf2] shows a glass transition at low temperatures.
- [N1114][NTf2] exhibits temperature-dependent crystallization behavior.
- Both ILs undergo glass transitions under elevated pressure.
- XRD and Raman spectroscopy revealed structural ordering/disordering during phase transitions (crystallization, glass transition, melting).
- High-frequency Raman spectra indicated conformational changes in cation and anion structures.
Conclusions:
- The study provides a comprehensive understanding of phase transitions in [N1114][NTf2] and [N1444][NTf2] under varying conditions.
- Pressure significantly influences the glass transition behavior of these ionic liquids.
- Molecular-level conformational changes accompany macroscopic phase transitions, offering insights into IL behavior.
More Related Videos
11:04Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
06:26Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Related Concept Videos
Phase Diagrams of Ternary Systems
Phase Transitions
Phase Transitions
Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
When dissolved in liquid ammonia, an alkali metal, such as sodium,...
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Phase Transitions: Melting and Freezing