Heat capacities at 298.15 K of the extended [C(n)C(1)im][Ntf(2)] ionic liquid series

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Marisa A A Rocha (Author) Other; Margarida Bastos (Author) FCUP; Joao A P Coutinho (Author) Other; Luis M N B F Santos (Author) FCUP

Journal

Title: Journal of Chemical Thermodynamics

Vol. 53

Pages: 140-143

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 59 Citations

Scopus - 60 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-002-5AW

DOI: 10.1016/j.jct.2012.04.025

Abstract (EN): High-precision heat capacities at 298.15 K of the [C(n)C(1)im][Ntf(2)] ionic liquid series were measured with an uncertainty of less than +/- 0.3%, using a drop heat capacity apparatus that was recently updated. The dependence of the c(p)(o) values on the alkyl side chain length for the extended ionic liquid series [C(n)C(1)im][Ntf(2)] (with n = 2 to 8, 10, and 12) displays a trend shift at [C(6)C(1)im][Ntf(2)], which is taken as an evidence for percolation limit. Above this limit there is an increase in the methylene group contribution to the molar heat capacity which is in agreement with the higher molar absolute entropies change observed from the (liquid + vapor) equilibrium results. The obtained experimental results support the model that the ionic liquids tend to be segregated into a polar network and non-polar domains, being followed by an increase of the entropy contribution of the non-polar domains.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4