resumo
In this work, the solubility of water in several tetradecyltrihexylphosphonium-based ionic liquids at 298.15 K. and densities and viscosities of both pure and water-saturated ionic liquids in a broad temperature range were measured. The selected ionic liquids comprise the common tetradecyltrihexylphosphonium cation combined with the following anions: bromide, chloride, bis(trifluoromethylsulfonyl)imide, decanoate, methanesulfonate, dicyanamide and bis(2,4,4-trimethylpentyl)phosphinate. The isobaric thermal expansion coefficients for pure and water-saturated ionic liquids were determined based on the density dependence with temperature. Taking into account that the excess molar volumes of the current hydrophobic water-saturated ionic liquids are negligible, the solubility of water was additionally estimated from the gathered density data and compared with the experimental solubilities obtained. Moreover, the experimental densities were compared with those predicted by the Gardas and Coutinho model while viscosity data were correlated using the Vogel-Tammann-Fulcher method. (c) 2011 Elsevier Ltd. All rights reserved.
palavras-chave
HIGH-PRESSURE DENSITIES; PHYSICAL-PROPERTIES; MUTUAL SOLUBILITIES; CHEMICAL-INDUSTRY; SURFACE TENSIONS; CARBON-DIOXIDE; PHOSPHONIUM; TEMPERATURE; IMIDAZOLIUM; AMMONIUM
categoria
Thermodynamics; Chemistry
autores
Neves, CMSS; Carvalho, PJ; Freire, MG; Coutinho, JAP
nossos autores
Catarina Maia Seco Seiça Neves
Investigador Auxiliar
Mara Guadalupe Freire Martins
Investigador Coordenador
Pedro J. Carvalho
Professor AuxiliarGrupos
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
The authors are thankful for financial support from Fundacao para a Ciencia e a Tecnologia through the Projects PTDC/QUI/72903/2008 and PTDC/EQU-FTT/102166/2008, Ph.D Grants SFRH/BD/70641/2010 and SFRH/BD/41562/2007 of Catarina M.S.S. Neves and Pedro J. Carvalho, respectively, and post-doctoral Grant SFRH/BPD/41781/2007 of Mara G. Freire. The authors also acknowledge Cytec Industries for providing all phosphonium-based ionic liquids used in this work.