abstract
Experimental measurements of the surface tension of six imidazolium-, pyridinium-, pyrrolidinium-, and phosphonium-based ionic liquids (ILs) with NTf(2) as the common anion and their dependence with the temperatures of (293 to 353) K at atmospheric pressure are presented. The set of selected ILs was chosen to investigate the influence of the length and position of the cation alkyl chain and the cation family on the surface tension of the ILs based on the NTf(2) anion. The surface thermodynamic functions such as surface entropy and enthalpy were derived from the temperature dependence of the surface tension, and their values indicate the importance of the surface ordering in ILs. The use of the Guggenheim and Eotvos correlations for the estimation of the critical temperatures of ILs is discussed, and a quantitative structure-property relationship (QSPR) correlation, previously extended for ILs, is here extended for the studied cations.
keywords
PHYSICAL-PROPERTIES; THERMODYNAMIC PROPERTIES; TEMPERATURE; MIXTURES; EICOSANE; WATER; TETRAFLUOROBORATE; TETRACOSANE; SOLUBILITY; DENSITIES
subject category
Thermodynamics; Chemistry; Engineering
authors
Carvalho, PJ; Neves, CMSS; Coutinho, JAP
our authors
Catarina Maia Seco Seiça Neves
Assistant Researcher
Pedro J. Carvalho
Assistant Professoracknowledgements
Received for review March 31, 2010. Accepted April 23, 2010. The authors are thankful for financial support from Fundacao para a Ciencia e a Tecnologia (Project PTDC/EQU-FTT/102166/2008) and Ph.D. Grant (SFRH/BD/41562/2007) of P.J.C.