화학공학소재연구정보센터
Journal of Chemical Thermodynamics, Vol.54, 49-54, 2012
Influence of the anion on the surface tension of 1-ethyl-3-methylimidazolium-based ionic liquids
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.