BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Dielectric properties of 1,1,1-trifluoroethane (HFC-143a) in the liquid phase

Participants in the publication
Anélia N. Gurova (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Ana P.C. Ribeiro (Author)
Carlos A. Nieto de Castro (Author)
Dep. Química e Bioquímica
CQE
Umesh V. Mardolcar (Author)
INSTITUTO SUPERIOR TÉCNICO

Summary
The relative permittivity (?r) data of 1,1,1-trifluoroethane (HFC-143a), (CAS N# 420-46-2), a hydrofluorocarbon (HFC) developed as a refrigerant that has zero ozone depletion potential, is reported. The relative permittivity of HFC-143a in the liquid phase was measured using a direct capacitance method at temperatures from T = 218 to 294 K and at pressures up to P = 15 MPa, for a frequency of 10 kHz. The uncertainty of the ?r measurements is estimated to be better than ±1.2 × 10−2. A complete set of tables of experimental data as a function of temperature, pressure and density, is presented that covers the dielectric property needs for most engineering applications. To study the dependence of ?r on density and temperature on a molecular basis, the theory developed by Vedam et al. and adapted by Diguet was applied to analyse the data. The Kirkwood modification of the Onsager equation was used to obtain the value of its dipole moment in the liquid phase (μ*). The apparent dipole moment obtained was μ* = 3.293 D. The effective dipole in the liquid state predicted by the Kirkwood–Frölich theory is 2.530 D. The measured values are compared with density functional and density functional self-consistent calculations (SCIPCM) of the electronic distribution and of the dipole moment of HFC-143a. Finally, the values of the isobaric thermal expansion and isothermal compressibility were estimated from the reported measurements.


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
Fluid Phase Equilibria

Publication Identifiers

Publisher
Elsevier BV



Document Identifiers
DOI - https://doi.org/10.1016/j.fluid.2008.09.022
URL - http://dx.doi.org/10.1016/j.fluid.2008.09.022

Tags
dipole moment 1 1 1-Trifluoroethane HFC-143a relative permittivity refrigerant liquid

Download