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

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

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

Revista

Título: Journal of Chemical Thermodynamics

Vol. 53

Páginas: 140-143

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 59 Citações

Scopus - 60 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 4