resumo
This paper reports the thermal, thermodynamic, thermophysical and surface properties of eight ionic liquids with fluorinated alkyl side chain lengths equal or greater than four carbon atoms. Melting and decomposition temperatures were determined together with experimental densities, surface tensions, refractive indices, dynamic viscosities and ionic conductivities in a temperature interval ranging from (293.15 to 353.15) K. The surface properties of these fluorinated ionic liquids were discussed and several thermodynamic functions, as well as critical temperatures, were estimated. Coefficients of isobaric thermal expansion, molecular volumes and free volume effects were calculated from experimental values of density and refractive index and compared with previous data. Finally, Walden plots were used to evaluate the ionicity of the investigated ionic liquids. (C) 2016 Elsevier Ltd. All rights reserved.
palavras-chave
PHYSICAL-PROPERTIES; ALKYL SUBSTITUENTS; REFRACTIVE-INDEX; CHAIN-LENGTH; SIDE-CHAINS; TEMPERATURE; ANION; TENSION; WATER; CYTOTOXICITY
categoria
Thermodynamics; Chemistry
autores
Vieira, NSM; Luis, A; Reis, PM; Carvalho, PJ; Lopes-da-Silva, JA; Esperanca, JMSS; Araujo, JMM; Rebelo, LPN; Freire, MG; Pereiro, AB
nossos autores
Andreia Veríssimo Luís
Bolseiro de investigação
Mara Guadalupe Freire Martins
Investigador Coordenador
Pedro J. Carvalho
Professor AuxiliarGrupos
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
Projectos
Development of New Oxygen Therapeutics using Fluorinated Ionic Liquids (PTDC/EQU-FTT/118800/2010)
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
Igy Technology: A Purication Platform using Ionic-Liquid-Based Aqueous Biphasic Systems (IGYPURTECH)
agradecimentos
The authors wish to thank M. M. Pineiro from University of Vigo for his contribution to this work and Fundacao para a Ciencia e a Tecnologia (FCT/MCTES - Ministerio da Ciencia, Tecnologia e Ensino Superior, Portugal) for financial support through Grants SFRH/BD/100563/2014 and SFRH/BPD/82264/2011, (N.S.M.V. and P.J.C), contracts under Investigator FCT 2014 (A.B.P. and J.M.M.A.) and 2012 (J.M.S.S.E), and through projects PTDC/EQU-FTT/118800/2010, PTDC/CTM-NAN/121274/2010, IF/00210/2014/CP1244/CT0003, UID/Multi/04551/2013 and UID/CTM/50011/2013. M.G. Freire acknowledges the European Research Council (ERC) for the Starting Grant ERC-2013-StG-337753. The NMR spectrometers are part of The National NMR Facility, supported by FCT/MEC (RECI/BBB-BQB/0230/2012).