Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (10): 2107-2113.doi: 10.3866/PKU.WHXB201304172


Ionic Association in Binary Ionic Liquids by Conductivity

NING Hui, HOU Min-Qiang, YANG De-Zhong, KANG Xin-Chen, HAN Bu-Xing   

  1. Institute of Chemistry, Chinese Academy of Sciences, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Beijing National Laboratory for Molecular Sciences, Beijing 100190, P. R. China
  • Received:2013-02-15 Revised:2013-04-16 Published:2013-09-26
  • Contact: HAN Bu-Xing
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20903109, 21073207).


In this study, the conductivity of 13 ionic liquids (ILs) and 25 related binary mixtures were determined at temperatures ranging from 293.15-323.15 K. The conductivity data of the pure ILs and their mixtures were fitted using the Vogel-Tammann-Fulcher (VTF) equation. The ionic association in the ILs and IL mixtures was discussed using the parameters of the VTF equation. It was demonstrated that at the same temperature, the ILs with short side chain cations, low charge density anions, and weak hydrogen bonding force between cations and anions usually exhibited high conductivity. Anions had a more obvious effect on conductivity than cations. The ionic association in the mixtures was affected not only by the species but also by the composition of the mixture.

Key words: Ionic liquid, Binary mixture, Conductivity, Ionic association, VTF equation