Surface tensions of imidazolium based ionic liquids: Anion, cation, temperature and water effect

authors	Freire, MG; Carvalho, PJ; Fernandes, AM; Marrucho, IM; Queimada, AJ; Coutinho, JAP
nationality	International
journal	JOURNAL OF COLLOID AND INTERFACE SCIENCE
author keywords	surface tension; ionic liquids; lmidazolium based ionic liquids; temperature dependence; water content; effective ionic concentration; molar conductivity; critical temperature
keywords	PHYSICOCHEMICAL PROPERTIES; PHYSICAL-PROPERTIES; ALKYL CHAIN; THERMODYNAMIC PROPERTIES; HYDROGEN-BONDS; MIXTURES; INTERFACE; PRESSURE; EICOSANE; BINARY
abstract	This work addresses the experimental measurements of the surface tension of eight imidazolium based ionic liquids (lLs) and their dependence with the temperature (288-353 K) and water content. The set of selected ionic liquids was chosen to provide a comprehensive Study of the influence of the cation alkyl chain length, the number of cation substitutions and the anion on the properties under study. The influence of water content in the surface tension was studied for several lLs as a function of the temperature as well as a function of water mole fraction, for the most hydrophobic IL investigated, [omim][PF(6)], and one of the more hygroscopic IL, [bmim][PF(6)]. The surface thermodynamic functions such as surface entropy and enthalpy were derived from the temperature dependence of the Surface tension values. (c) 2007 Elsevier Inc. All rights reserved.
publisher	ACADEMIC PRESS INC ELSEVIER SCIENCE
issn	0021-9797
year published	2007
volume	314
issue	2
beginning page	621
ending page	630
digital object identifier (doi)	10.1016/j.jcis.2007.06.003
web of science category	Chemistry, Physical
subject category	Chemistry
unique article identifier	WOS:000249312800034