9. Dielectric Properties of Ionic Liquids: Achievements So Far and Challenges Remaining

  1. Natalia V. Plechkova and
  2. Kenneth R. Seddon
  1. Hermann Weingärtner

Published Online: 14 MAR 2014

DOI: 10.1002/9781118839706.ch9

Ionic Liquids Further UnCOILed: Critical Expert Overviews

Ionic Liquids Further UnCOILed: Critical Expert Overviews

How to Cite

Weingärtner, H. (2014) Dielectric Properties of Ionic Liquids: Achievements So Far and Challenges Remaining, in Ionic Liquids Further UnCOILed: Critical Expert Overviews (eds N. V. Plechkova and K. R. Seddon), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118839706.ch9

Editor Information

  1. The Queen's University of Belfast

Author Information

  1. Physical Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Bochum, Germany

Publication History

  1. Published Online: 14 MAR 2014
  2. Published Print: 20 MAR 2014

ISBN Information

Print ISBN: 9781118438633

Online ISBN: 9781118839706

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Keywords:

  • dielectric dispersion curve;
  • electrically conducting systems;
  • ionic liquids;
  • microwave spectra;
  • solvation dynamics;
  • static dielectric constants;
  • terahertz spectra;
  • volatile organic compounds (VOCs)

Summary

The static dielectric constant of an ionic liquid is not measurable by conventional methods because the samples are largely short-circuited by their intrinsic electrical conductance. It is, however, possible to determine this quantity by recording the frequency-dependent dielectric dispersion curve in the microwave regime, followed by extrapolation to quasi-static conditions. This review compiles the information on static dielectric constants available from such experiments, and discusses trends in the cation and anion dependence. The results classify most aprotic ionic liquids as moderately polar solvents with dielectric constants of the order of ϵ = 10–12; protic ionic liquids, however, exhibit much higher values.