Relative permittivity free volume

The term A is related to the solvent density and molecular weight and to the free volumes of the ions and the ion-pair [59]. Fjoi is the difference between the molar ion-pair solvation energy and the free ion solvation energy. The theory does not predict a simple linearity of In with lie. Actually solvent effects other than that due to the relative permittivity of the solvent are easily predicted, since the macroscopic e is only a rudimentary description of the real attenuation of the ionic interactions due... 

An increase in fractional free volume will reduce the number of polarisable groups per unit volume, and thereby reduce the relative permittivity of the polymer. Quantitatively, the effect may be estimated by means of the Clausius-Mossotti/Lorenz-Lorentz model for dielectric mixing (Bottcher, 1978) ... 

Here 6t is the volume fraction of the z th component, and e is its relative permittivity in pure form. For the case of a two-component mixture of free... 

Generally, we must conclude that control of free volume is just as important as selection of groups with low polarisability, in order to achieve polymer molecular structures with low relative permittivities. 

G. Hougham, G. Tesoro, A. Viehbeck, Influence of free volume change on the relative permittivity and refractive index in fluoropolyimides. Macromolecules 29 (10) (1996) 3453-3456. 

Hougham G, Tesoro G, Viehbeck A. Influence of Free Volume Change on the Relative Permittivity and Refractive Index in Fluoropolyimides. Macromolecules 1996 29 3453-3456. 

Dielectric analysis measures two fundamental characteristics of a material—permittivity e and conductivity o (or resistivity p)—as functions of time, temperature, and AC radial frequency (O. As was discussed above, permittivity and conductivity are two parameters characteristic of respective abilities of analyzed material to store electrical energy and transfer electric charge. Both of these parameters are related to molecular activity. For example, a "dielectric" is a material whose capacitive current (out of phase) exceeds its resistive (in phase) current. An "ideal dielectric" is an insulator with no free charges that is capable of storing electrical energy. The Debye Equation (Eq. 1-12) relates the relative permittivity e to a concept of material polarization density P [C/nP], or electrical dipole moment [C/m] per unit volume [m ], and the applied electric field V ... 

The external static electric field applied to a dielectric material induces fire polarisation P, that is the dipole moment per unit volume. For low fields P is prt rtional to the electric field E [1>3], P = 8o(8s - 1) E, where 8s is the relative dielectric permittivity or dielectric constant and 8o is the dielectric permittivity of free space. All these quantities concom the macroscopic volume of the dielectric medium. In order to relate them to the relevant microscopic param ers (for example dipole moment and polarisability) the local electric field Eioc acting on a molecule must be known. The relation between Eioc and E is the crucial problem of the physics of dielectrics and has not been solved in general. For isotropic fluids the Onsager theory is commonly used [4]. 

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