Dielectric constant and dipole moment of hydrofluorocarbon refrigerant mixtures R404A, R407C, and R507

2000 ◽  
Vol 32 (6) ◽  
pp. 631-651 ◽  
Author(s):  
Filipe de Brito ◽  
Anelia Gurova ◽  
Carlos Nieto de Castro ◽  
Umesh Mardolcar
Keyword(s):  
Dielectric Constant ◽  
Dipole Moment ◽  
Refrigerant Mixtures

Temperaturabhängigkeit der statischen Dielektrizitätskonstante und des optischen Brechungsindexes von Flüssigkeiten

1975 ◽  
Vol 30 (3) ◽  
pp. 287-291 ◽  
Author(s):  
I. Gryczyński ◽  
A. Kawski
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Dipole Moment ◽  
Dipole Moments ◽  
Mixed Solvents ◽  
Temperature Changes ◽  
Temperature Dependences ◽  
Solvent Shifts ◽  
Pure And Mixed Solvents ◽  
Good Agreement

A variation of the temperature changes the static dielectric constant (ε) and the refractive index (n) of solvents and, in conjunction with the measurement of solvent shifts of absorption and fluorescence maxima, allows the investigation of dipole moment changes of solutes in the excited state. For this purpose, investigations of the temperature dependences of ε and n of some pure and mixed solvents of different polarities have been made. It is found that the excited dipole moments of indole, 1,2-dimethylindole, 2,3-dimethylindole and tryptophan obtained from the shifts of the fluorescence maxima in mixed solvents at high temperatures are in good agreement with those obtained in other ways.

Bromine Pentafluoride. The Electric Dipole Moment in the Vapor State and the Dielectric Constant of the Liquid1

1956 ◽  
Vol 78 (1) ◽  
pp. 44-45 ◽  
Author(s):  
Max T. Rogers ◽  
Richard D. Pruett ◽  
H. Bradford Thompson ◽  
John L. Speirs
Keyword(s):  
Dielectric Constant ◽  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Vapor State

Détermination de propriétés diélectriques de substances polaires: conditions d'applicabilité de l'équation d'Omini

1982 ◽  
Vol 60 (18) ◽  
pp. 2398-2402
Author(s):  
Léo Dégrève ◽  
Paulo Roberto Brossi Pelissari ◽  
Maria Marcia Murta
Keyword(s):  
Dielectric Constant ◽  
Dipole Moment ◽  
Nonpolar Solvents

An equation which allows for the determination of the dipole moment and polarizability of polar substances via the dielectric constant of solutions of the substance in nonpolar solvents is tested using different solute–solvent pairs. The results indicate that this equation provides good values of the dipole moment and of the polarizability if the solvent is correctly chosen. [Journal translation]

Dielectric Relaxation Studies of Ternary Mixture of Dimethyl Phthalate and Heptanol in Benzene Solution in the Microwave Region

2015 ◽  
Vol 70 (7) ◽  
pp. 507-512
Author(s):  
A. Mushtaq Ahmed Khan ◽  
M. Subramanian
Keyword(s):  
Dielectric Constant ◽  
Dipole Moment ◽  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Benzene Solution ◽  
Microwave Frequency ◽  
Viscous Force ◽  
Dimethyl Phthalate ◽  
Flow Process ◽  
Relaxation Studies

AbstractThe molecular structure and molecular forces in liquids and solutions, in particular, have been investigated by dielectric relaxation studies. The nature and strength of the molecular interactions have been established as the main cause for the chemical behaviour of compounds. The dielectric behaviour of dimethyl phthalate with heptanol in benzene solution has been studied at a microwave frequency of 9.36 GHz at different temperatures 303, 308, and 313 K. Different dielectric quantities such as dielectric constant (ε′), dielectric loss (ε″), static dielectric constant (ε0), and dielectric constant at optical frequency (ε∞) have been determined. The relaxation time τ has been calculated by both Higasi’s method and Cole–Cole method. The dielectric relaxation process can be treated as a rate process just like the viscous flow process. The complex system investigated shows the maximum relaxation time values at high temperatures by both Higasi’s method and Cole–Cole method. The molar free energies of activation of dipole moment (ΔFτ) and viscous force (ΔFη) have also been reported. The excess dipole moment is also determined. The excess dipole moment is a qualitative index for the presence of a hydrogen bond in the ternary system. The value of Δμ obtained in our study indicates the presence of hydrogen bonds between the components of the mixture. The system investigated shows that the relaxation time value increases with the increase in the concentration of solute.

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