Jump to main content
Jump to site search

Issue 45, 2015
Previous Article Next Article

Solubility of n-butane and 2-methylpropane (isobutane) in 1-alkyl-3-methylimidazolium-based ionic liquids with linear and branched alkyl side-chains

Author affiliations

Abstract

The solubility of n-butane and 2-methylpropane (isobutane) in three ionic liquids – 1-(2-methylpropyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [(2mC3)C1im][Ntf2], 1-(3-methylbutyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [(3mC4)C1im][Ntf2] and 1-methyl-3-pentylimidazolium bis(trifluoromethylsulfonyl)imide [C5C1im][Ntf2] – has been measured at atmospheric pressure from 303 to 343 K. Isobutane is less soluble than n-butane in all the ionic liquids. Henry's constant values range from 13.8 × 105 Pa for n-butane in [C5C1im][Ntf2] at 303 K to 64.5 × 105 Pa for isobutane in [(2mC3)C1im][Ntf2] at 343 K. The difference in solubility between the two gases can be explained by a more negative enthalpy of solvation for n-butane. A structural analysis of the pure solvents and of the solutions of the gases, probed by molecular dynamics simulations, could explain the differences found in the systems: (i) the nonpolar domains of the ionic liquids accommodate better the long and more flexible n-butane solute; (ii) the small differences in solubility of each gas in the ionic liquids with the same number of carbon atoms in the alkyl side-chains are explained by the absence of large structural differences in the pure solvents. In all cases, the structural analysis of the four ionic liquids confirms that the studied gases can act as probes of the molecular structure of the ionic liquids, the simulations being always compatible with the experimental solubility data.

Graphical abstract: Solubility of n-butane and 2-methylpropane (isobutane) in 1-alkyl-3-methylimidazolium-based ionic liquids with linear and branched alkyl side-chains

Back to tab navigation

Supplementary files

Publication details

The article was received on 17 Sep 2015, accepted on 15 Oct 2015 and first published on 15 Oct 2015


Article type: Paper
DOI: 10.1039/C5CP05572E
Citation: Phys. Chem. Chem. Phys., 2015,17, 30328-30342
  •   Request permissions

    Solubility of n-butane and 2-methylpropane (isobutane) in 1-alkyl-3-methylimidazolium-based ionic liquids with linear and branched alkyl side-chains

    L. Pison, K. Shimizu, G. Tamas, J. N. C. Lopes, E. L. Quitevis and M. F. C. Gomes, Phys. Chem. Chem. Phys., 2015, 17, 30328
    DOI: 10.1039/C5CP05572E

Search articles by author

Spotlight

Advertisements