resumo
Experimental data for the density, viscosity, refractive index, and surface tension of four sulfonium- and ammonium-based ionic liquids (ILs) with the common bis(trifluoromethylsulfonyl)imide anion were measured in the temperature range between 288.15 and 353.15K and at atmospheric pressure. The ILs considered include butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [N-4111][NTf2], tributyl-methylammonium bis(trifluoromethylsulfonyl)imide, [N-4441][NTf2], diethylmethylsulfonium bis(trifluoromethylsulfonyl)imide, [S-221] [NTf2], and triethylsulfonium bis(trifluoromethylsulfonyl)imide, [S-222][NTf2]. Based on the gathered results and on data taken from literature, the impact of the cation isomerism and of the size of the aliphatic tails, as well as the effect resulting from the substitution of a nitrogen by a sulfur atom as the cation central atom, on the thermophysical properties of sulfonium- and ammonium-based Its is discussed here. Remarkably, more symmetric cations present a lower viscosity for the same, and sometimes even for higher, alkyl chain lengths at the cation. Additional derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperature for the investigated ILs were also estimated and are presented and discussed. (C) 2014 Elsevier B.V. All rights reserved.
palavras-chave
TEMPERATURE MOLTEN-SALTS; EXTENDED PRESSURE RANGE; SENSITIZED SOLAR-CELLS; SURFACE-TENSION MEASUREMENTS; THERMODYNAMIC PROPERTIES; PHYSICOCHEMICAL PROPERTIES; ELECTROCHEMICAL PROPERTIES; LOW-VISCOSITY; CARBON-DIOXIDE; BIS(TRIFLUOROMETHYLSULFONYL)IMIDE ANION
categoria
Thermodynamics; Chemistry; Engineering
autores
Bhattacharjee, A; Luis, A; Santos, JH; Lopes-da-Silva, JA; Freire, MG; Carvalho, PJ; Coutinho, JAP
nossos autores
Andreia Veríssimo Luís
Bolseiro de investigação
Arijit Bhattacharjee
Bolseiro de pós-Doutoramento
João Henrique Picado Madalena Santos
Estudante de doutoramento
Mara Guadalupe Freire Martins
Investigador Coordenador
Pedro J. Carvalho
Professor AuxiliarGrupos
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
Projectos
Igy Technology: A Purication Platform using Ionic-Liquid-Based Aqueous Biphasic Systems (IGYPURTECH)
agradecimentos
The authors acknowledge FEDER funds through the COMPETE operational program and Fundacao para a Ciencia e Tecnologia-FCT through the projects PTDC/QUI-QUI/121520/2010 and PEst-C/CTM/LA0011/2013. P.J.C. and A.B. also acknowledge FCT for their post-doctoral grants SFRH/BPD/82264/2011 and SFRH/BPD/77858/2011, respectively. M. G. Freire acknowledges the European Research Council (ERC) for the starting Grant ERC-2013-StG-337753.