title: Fluorination effects on the thermodynamic, thermophysical and surface properties of ionic liquids.
abstract: 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.
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: N S M
authors.initials: NSM
authors.lastname: Vieira
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Luís
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: P M
authors.initials: PM
authors.lastname: Reis
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: P J
authors.initials: PJ
authors.lastname: Carvalho
authors.affiliation: QOPNA Unit, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: J A
authors.initials: JA
authors.lastname: Lopes-da-Silva
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: J M S S
authors.initials: JMSS
authors.lastname: Esperança
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: J M M
authors.initials: JMM
authors.lastname: Araújo
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: L P N
authors.initials: LPN
authors.lastname: Rebelo
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: M G
authors.initials: MG
authors.lastname: Freire
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: A B
authors.initials: AB
authors.lastname: Pereiro
keywords: Fluorinated ionic liquids; Physical and Thermal properties; Surface tension; Thermodynamic functions; Walden plot