Thermophysical properties of [C(N-1)C(1)im][PF6] ionic liquids

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Marisa A A Rocha (Author) Other; Filipe M S Ribeiro (Author) Other; Ana Lobo M C L Ferreira (Author) FCUP; Joao A P Coutinho (Author) Other; Luis M N B F Santos (Author) FCUP

Journal

Title: Journal of Molecular Liquids

Vol. 188

Pages: 196-202

ISSN: 0167-7322

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 60 Citations

Scopus - 63 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-006-JCT

DOI: 10.1016/j.molliq.2013.09.031

Abstract (EN): Densities, viscosities and refractive index, as a function of temperature, and isobaric thermal expansion coefficient, were determined for 1-alkyl-3-methylimidazolium hexafluorophosphate, [C(N - 1)C(1)im]PF6] (where N = 5 to 10) series of ionic liquids. The density presents a regular decrease along the ionic liquid series, with no detectable alkyl chain length dependence of the thermal expansion coefficient. Both the refractive index and viscosity show a trend shift along the series around the [C(6)C(1)im][PF6] that could be associated to the impact of the change in the nanostructuration of the ionic liquids. The experimental results are compared with the analogous [C(N - 1)C(1)im][NTf2] series and the effect of the anion is analyzed. The sphericity of the [PF6](-) anion is reflected in the lower pre-exponential VTF parameter, A(eta), and the higher viscosity of the [C(N - 1)C(1)im][PF6]. when compared with the [C(N - 1)C(1)im][NTf2] series, is ruled by the higher energy barriers, which are related with stronger electrostatic interaction due to the low charge dispersion of the [PF6](-),anion.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7