VLE and LLE of perfluoroalkane + alkane mixtures

Duce, Celia; Tiné, Maria Rosaria; Lepori, Luciano; Matteoli, Enrico

doi:10.1016/s0378-3812(01)00815-9

Cited by 53 publications

(70 citation statements)

References 26 publications

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“…The unlike interactions between FE − CE, FE − CM, FE − C4, FM − CE, FM − CM, FM − C4 pairs of groups are estimated from the experimental liquid-liquid phaseequilibrium data for the C 6 F 14 + C 6 H 14 , C 8 F 18 + C 6 H 14 , C 8 F 18 + C 9 H 20 , and C 8 F 18 + C 8 H 18 binary mixtures [67,70,[93][94][95][96][97][98][99][100][101][102]. The connecting groups (FH and FHE), which bridge the alkyl and the perfluoroalkyl chains, are introduced to account for the presence of the dipole moment between the two chemical moieties in an effective manner; the FH and FHE groups are characterized by dispersion energies which differ markedly from the values for the alkyl (CE, CM, C4) or perfluoroalkyl (FE, FM) groups.…”

Section: Saft-γ Cg Mie Force Fieldmentioning

confidence: 99%

SAFT-γ force field for the simulation of molecular fluids: 8. Hetero-segmented coarse-grained models of perfluoroalkylalkanes assessed with new vapour–liquid interfacial tension data

et al. 2016

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The air-liquid interfacial behaviour of linear perfluoroalkylalkanes (PFAAs) is reported through a combined experimental and computer simulation study. The surface tensions of seven liquid PFAAs (perfluorobutylethane, F 4 H 2 ; perfluorobutylpentane, F 4 H 5 ; perfluorobutylhexane, F 4 H 6 , perfluorobutyloctane, F 4 H 8 ; perfluorohexylethane, F 6 H 2 ; perfluorohexylhexane, F 6 H 6 ; and perfluorohexyloctane, F 6 H 8 ) are experimentally determined over a wide temperature range (276-350 K). The corresponding surface thermodynamic properties and the critical temperatures of the studied compounds are estimated from the temperature dependence of the surface tension. Experimental density and vapour pressure data are employed to parameterize a generic heteronuclear coarse-grained intermolecular potential of the SAFT-γ family for PFAAs. The resulting force field is used in direct molecular-dynamics simulations to predict the experimental tensions with quantitative agreement and to explore the conformations of the molecules in the interfacial region revealing a preferential alignment of the PFAA molecules towards the interface and an enrichment of the perfluoro groups at the outer interface region.

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Section: Saft-γ Cg Mie Force Fieldmentioning

confidence: 99%

SAFT-γ force field for the simulation of molecular fluids: 8. Hetero-segmented coarse-grained models of perfluoroalkylalkanes assessed with new vapour–liquid interfacial tension data

et al. 2016

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“…The mixture specimen containing 35.04 mol% C 6 F 14 was prepared using an analytical balance with a precision of ± 0.3 mg. Corrections were made to account for the evaporation of constituents in the mixing vessel (for these evaluations we used information about vapor-liquid equilibria for n-perfluorohexane, n-hexane, and their mixtures from the NIST Chemistry Web Book [9] and [2]). The specimen volume was about 65 cm 3 .…”

Section: Density Of the Constituents And The Homogeneous Solutionmentioning

confidence: 99%

“…The critical solution point of n-perfluorohexane-n-hexane mixtures is close to room temperature; thus, they are suitable candidates for study and, in particular, for testing of theoretical predictions concerning the behavior of matter in the critical region. Nevertheless, the behavior of the liquid-liquid coexistence curve near the critical point has not been sufficiently explored, and literature data are somewhat contradictory [1,2]. In this article are presented new data for the liquidliquid phase boundary of the C 6 F 14 -C 6 H 14 system, obtained by the γ -ray attenuation technique.…”

Section: Introductionmentioning

confidence: 99%

Liquid–Liquid Coexistence Curve of n-Perfluorohexane–n-Hexane System

2007

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The shape of the liquid-liquid phase boundary of the C 6 F 14 -C 6 H 14 system near the critical solution point has been determined by a γ -ray attenuation technique. According to the measurements, the critical solution temperature and composition are 295.69 ± 0.02 K and 36.1 ± 0.3 mol% C 6 F 14 , respectively. The critical exponent of the liquid-liquid coexistence curve is 0.322 ± 0.008. Midpoints of the coexistence curve exhibit a departure from the law of the rectilinear diameter.

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“…Structural factors, such as the rigidity of fluorinated chains (as opposed to the characteristic flexibility of hydrogenated chains) and the incompatibility of cross-sectional diameters of hydrogenated and fluorinated chains, may also contribute to the observed behavior. 1,2 In much of our previous work, we have been studying the combined presence of the mutually phobic segments (hydrogenated and perfluorinated) and some form of association, hoping to clarify how it can affect the structure of the liquid and induce organization. We have accomplished a systematic study of perfluoroalkylalkanes (PFAA).…”

Section: Introductionmentioning

confidence: 99%

Liquid Mixtures Involving Hydrogenated and Fluorinated Alcohols: Thermodynamics, Spectroscopy, and Simulation

Morgado¹,

García

Ilharco³

et al. 2016

J. Phys. Chem. B

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This article reports a combined thermodynamic, spectroscopic, and computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,2,3,3,4,4,4-heptafluoro-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra.

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VLE and LLE of perfluoroalkane + alkane mixtures

Cited by 53 publications

References 26 publications

SAFT-γ force field for the simulation of molecular fluids: 8. Hetero-segmented coarse-grained models of perfluoroalkylalkanes assessed with new vapour–liquid interfacial tension data

SAFT-γ force field for the simulation of molecular fluids: 8. Hetero-segmented coarse-grained models of perfluoroalkylalkanes assessed with new vapour–liquid interfacial tension data

Liquid–Liquid Coexistence Curve of n-Perfluorohexane–n-Hexane System

Liquid Mixtures Involving Hydrogenated and Fluorinated Alcohols: Thermodynamics, Spectroscopy, and Simulation

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