abstract
The air-liquid interfacial tensions of eight ionic liquids, from (298 to 343) K, are presented in this work. The studied ionic liquids are formed by the fixed 1-ethyl-3-methylimidazolium cation combined with the anions acetate, dicyanamide, dimethylphosphate, methylphosphonate, methanesulfonate, thiocyanate, tosylate, and trifluoromethanesulfonate. The selected ionic liquids allowed a comprehensive study through the influence of the anion nature on the surface tension and on their surface ordering. A slight dependence of the surface tension with the ionic liquid molar volume was identified. The surface thermodynamic functions are mainly controlled by the anion which constitutes a given ionic liquid. The hypothetical critical temperatures of all ionic liquids were estimated by means of the Eotvos and Guggenheim correlations and are presented. (C) 2012 Elsevier Ltd. All rights reserved.
keywords
ALKYL CHAIN-LENGTH; THERMODYNAMIC PROPERTIES; MOLECULAR SIMULATIONS; CARBON-DIOXIDE; TEMPERATURE; IMIDAZOLIUM; PRESSURE; DENSITY; SOLUBILITIES; INTERFACES
subject category
Thermodynamics; Chemistry
authors
Almeida, HFD; Teles, ARR; Lopes-da-Silva, JA; Freire, MG; Coutinho, JAP
our authors
Ana Rita Ribeiro Teles
Financial Officer
Mara Guadalupe Freire Martins
Coordinating ResearcherGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
acknowledgements
This work was funded by QREN SI-I&DT Project No 11551 from UE/FEDER through COMPETE program. The authors also acknowledge FCT- Fundacao para a Ciencia e a Tecnologia for the Pest-C/CTM/LA0011/2011 project and post-doctoral grant SFRH/BPD/41781/2007 of M.G. Freire.