The speed of sound, and derived thermodynamic properties of liquid trifluoromethane (HFC23) fromT=(258 to 303)K at pressures up to 65MPa

Pires, P.F.; Guedes, Henrique J. R.

doi:10.1006/jcht.1998.0464

Cited by 10 publications

(14 citation statements)

References 9 publications

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“…A new high-pressure acoustic cell was built in order to measure the speed of propagation of ultrasonic waves in ionic liquids. The cell shape was based on one previously built 16,17 with the total volume of the system reduced to one that would be workable for IL. Figure 1 shows both a diagram and a photograph of the speed of sound cell.…”

Section: Methodsmentioning

confidence: 99%

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C₃mim][NTf₂] and [C₅mim][NTf₂]

et al. 2006

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The current study focuses on 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [C 3 mim][NTf 2 ], and 1-pentyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [C 5 mim][NTf 2 ]. The objective is to study the influence of pressure as well as that of the cation's alkyl chain length on several properties of this type of ionic liquids. Speed of propagation of ultrasound waves and densities in pure ionic liquids as a function of temperature and pressure have been determined. Other thermodynamic properties such as compressibilities and expansivities have been obtained. Speed of sound measurements have been carried out in broad ranges of temperature (298 < T/K < 338) and pressure (0.1 < p/MPa < 200). A novel high-pressure ultrasonic cell was designed and built to allow for precise speed of sound measurements in liquids. The uncertainty of the speed of sound measurements is 0.05 %. A detailed description of the cell is presented. Density measurements have been performed over a broad range of temperature (298 < T/K < 333) and pressure (0.1 < p/MPa < 60) using a vibrating-tube densimeter. The density overall uncertainty is 0.02 %.

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Section: Methodsmentioning

confidence: 99%

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C₃mim][NTf₂] and [C₅mim][NTf₂]

et al. 2006

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“…Although the properties of these fluorocarbons are interesting, only very limited structural information is available so far. HCF 3 is discussed as replacement for chlorinated hydrocarbons as refrigerant since it it has no ozone damaging effect, it has a shorter atmospheric lifetime and, hence, a lower global warming potential and it presents no toxological risk [6,7]. HCF 3 is discussed for extraction applications [8] and it has been shown, that the enatioselectivity of asymmetric catalysis can be controlled by the density of the fluoroform solvent [9].…”

Section: Introductionmentioning

confidence: 99%

The structure of fluid trifluoromethane and methylfluoride

Neuefeind

Fischer²,

Schröer³

2000

J. Phys.: Condens. Matter

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We present hard X-ray and neutron diffraction measurements on the polar fluorocarbons HCF 3 and H 3 CF under supercritical conditions and for a range of molecular densities spanning about a factor of ten. The Levesque-Weiss-Reatto inversion scheme has been used to deduce the site-site potentials underlying the measured partial pair distribution functions. The orientational correlations between adjacent fluorocarbon molecules -which are characterized by quite large dipole moments but no tendency to form hydrogen bonds -are small compared to a highly polar system like fluid hydrogen chloride. In fact, the orientational correlations in HCF 3 and H 3 CF are found to be nearly as small as those of fluid CF 4 , a fluorocarbon with no dipole moment.PACS: 61.20.Qg, 61.20.Ja, 61.25.Em IntroductionThe understanding of dielectric properties resulting from orientational correlations [1,2], as well as the determination of orientational correlations from diffraction experiments [3,4], are long standing problems in the physics of molecular fluids. The simple fluorocarbons HCF 3 and H 3 CF are very interesting model substances in this context, as they posses rather large dipole moments (1.65 · 3.336 · 10 −30 Cm), in the case of trifluoromethane -the same as that of the water molecule) but no tendency to form hydrogen bonds [5]. The investigation of the structure of the simple fluorocarbons H 3 CF and HCF 3 thus enables the study of the structural effect of the molecular dipole alone.Although the properties of these fluorocarbons are interesting, only very limited structural information is available so far. HCF 3 is discussed as replacement for chlorinated hydrocarbons as refrigerant since it it has no ozone damaging effect, it has a shorter atmospheric lifetime and, hence, a lower global warming potential and it presents no toxological risk [6,7]. HCF 3 is discussed for extraction applications [8] and it has been shown, that the enatioselectivity of asymmetric catalysis can be controlled by the density of the fluoroform solvent [9]. The crystal structure of HCF 3 has been determined by a neutron powder diffraction experiment [10] and the molecular geometry by a gas phase electron diffraction

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“…The vapor phase data for R-22 measured with a spherical resonator were adopted from He et al, while the vapor phase data for R-23 measured with an annular resonator originates from Jarvis et al . The speed of sound data measured in the liquid phase of R-22 with an ultrasonic interferometer were adopted from Takagi and Teranishi, and the data for the liquid phase of R-23 measured with the pulse-echo method come from Pires and Guedesa . The interaction coefficients of the evaluated models were set to unity due to the lack of experimental data for vapor liquid equilibrium of the investigated mixtures.…”

Section: Evaluation Of the Resultsmentioning

confidence: 99%

“…36 The speed of sound data measured in the liquid phase of R-22 with an ultrasonic interferometer were adopted from Takagi and Teranishi, 40 and the data for the liquid phase of R-23 measured with the pulseecho method come from Pires and Guedesa. 41 The interaction coefficients of the evaluated models were set to unity due to the lack of experimental data for vapor liquid equilibrium of the investigated mixtures. The calculations of speed of sound in mixtures were thus carried out in a predictive manner.…”

Section: Evaluation Of the Resultsmentioning

confidence: 99%

Speed of Sound Data in Pure Refrigerants R-116 and R-218 and Their Mixtures: Experiment and Modeling

Martin

Vacek

2016

J. Chem. Eng. Data

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We present our latest research on speed of sound in mixtures of fluorocarbons that are used as unconventional refrigerants in various applications within high-technology electronics installations, in particle detectors, and elsewhere in the electronics industry. A new automated apparatus for speed of sound measurements has been prepared, and the experimental data that were gathered were compared to three equations of state. Actual speed of sound measurements were carried out in two fluorocarbons, R-218 (C 3 F 8 ) and R-116 (C 2 F 6 ), their mutual mixture, and mixtures of C 3 F 8 with nitrogen. In total, more than 600 data points along 15 isotherms from 250 to 324 K and pressures up to 0.5 MPa were obtained. The range of the obtained speed of sound was from 102.5 to 144.8 m•s −1 . The sPC-SAFT, SAFT-BACK, and one cubic equation of state were evaluated in terms of speed of sound prediction accuracy in both liquid and vapor phases using our own data and data adopted from literature.

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The speed of sound, and derived thermodynamic properties of liquid trifluoromethane (HFC23) fromT=(258 to 303)K at pressures up to 65MPa

Cited by 10 publications

References 9 publications

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C₃mim][NTf₂] and [C₅mim][NTf₂]

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C₃mim][NTf₂] and [C₅mim][NTf₂]

The structure of fluid trifluoromethane and methylfluoride

Speed of Sound Data in Pure Refrigerants R-116 and R-218 and Their Mixtures: Experiment and Modeling

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The speed of sound, and derived thermodynamic properties of liquid trifluoromethane (HFC23) fromT=(258 to 303)K at pressures up to 65MPa

Cited by 10 publications

References 9 publications

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C3mim][NTf2] and [C5mim][NTf2]

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C3mim][NTf2] and [C5mim][NTf2]

The structure of fluid trifluoromethane and methylfluoride

Speed of Sound Data in Pure Refrigerants R-116 and R-218 and Their Mixtures: Experiment and Modeling

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Product

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Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C₃mim][NTf₂] and [C₅mim][NTf₂]

Density, Speed of Sound, and Derived Thermodynamic Properties of Ionic Liquids over an Extended Pressure Range. 4. [C₃mim][NTf₂] and [C₅mim][NTf₂]