Thermophysical and Thermodynamic Properties of 1-Butyl-3-methylimidazolium Tetrafluoroborate and 1-Butyl-3-methylimidazolium Hexafluorophosphate over an Extended Pressure Range

The current study focuses on 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4], and 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6]. The objective is to study the influence of pressure as well as that of the anion on several properties of this type of ionic liquid. The speed of...

Full description

Saved in:
Bibliographic Details
Published in:Journal of chemical and engineering data 2005-05, Vol.50 (3), p.997-1008
Main Authors: Gomes de Azevedo, Ricardo, Esperança, José M. S. S, Najdanovic-Visak, Vesna, Visak, Zoran P, Guedes, Henrique J. R, Nunes da Ponte, Manuel, Rebelo, Luís P. N
Format: Article
Language:English
Subjects:
Chemical thermodynamics
Chemistry
Exact sciences and technology
General and physical chemistry
General. Theory
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The current study focuses on 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4], and 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6]. The objective is to study the influence of pressure as well as that of the anion on several properties of this type of ionic liquid. The speed of sound and densities in pure ionic liquids (ILs) as a function of temperature and pressure have been determined. Several other thermodynamic properties such as compressibilities, expansivities, and heat capacities have been obtained. To the best of our knowledge, this research comprises both the first speed of sound data and the first evaluation of heat capacities at high pressures for ILs. Speed of sound measurements have been carried out in broad ranges of temperature (283 < T/K < 323) and pressure (0.1 < p/MPa < 150), sometimes inside the metastable liquid region using a nonintrusive microcell. The T−P melting line of [bmim][PF6] has also been determined by an acoustic method. Density measurements have been performed for broad ranges of temperature (298 < T/K < 333) and pressure (0.1 < p/MPa < 60) using a vibrating tube densimeter. The pressure dependence of the heat capacities, which is generally mild, is found to be highly dependent on the curvature of the temperature dependence of the density.
ISSN:0021-9568
1520-5134
DOI:10.1021/je049534w