Dielectric constant refractive index

These expressions appear more applieable to nonpolar solvents or mixtures than to polar solvents. The nature of the solvation process (and the radii and so forth of the solvated reactants) may stay approximately constant in the first situation but almost certainly will not in the seeond. The function (E>op A ) features in the reorganisation term Xq which is used for estimating rate constants for redox reactions (Eqn. 5.23). is the optical dielectric constant and Dj the static dielectric constant (= refractive index ). 

The physical properties of solvents greatly influence the choice of solvent for a particular application. The solvent should be liquid under the temperature and pressure conditions at which it is employed. Its thermodynamic properties, such as the density and vapor pressure, temperature and pressure coefficients, as well as the heat capacity and surface tension, and transport properties, such as viscosity, diffusion coefficient, and thermal conductivity, also need to be considered. Electrical, optical, and magnetic properties, such as the dipole moment, dielectric constant, refractive index, magnetic susceptibility, and electrical conductance are relevant, too. Furthermore, molecular... 

The availability of experimental dipole moment (Section Ill-a), dielectric constant, refractive index and density data for NMA has made possible the calculation of values of the correlation factor (g) using the following equation of Kirkwood97 and Frohlich98) ... 

Dipole moment Cohesive pressure Dielectric constant Refractive index Melting point and boiling point Donor numbers Acceptor numbers E, a, and 7t ... 

Tab. 1.2. Relative static dielectric constant, refractive index (measured at the frequency of sodium D lines) and dipole moment for a few/ molecules.

These difficulties have been avoided by Frohlich whose Reasoning is very similar to Kirkwood s but who has chosen his model in such a manner that he need consider no boundary effect. He has treated the deformation polarization as a macroscopic phenomenon. Molecules are replaced by a set of nondeformable point dipoles, having a moment p and placed in a continuous medirnn of dielectric constant= refractive index), accounting for deformation effects. The moment of a spherical molecule is given by... 

The optical detection of vapors was based on the changes in optical properties of thin films, such as dielectric constant, refractive index, and so forth, when they were exposed to the VOCs. In the solid thin films, there are n-n interactions between the analytes and phthalocyanines/porphyrins. Interactions with VOCs can induce a change of these interactions, leading to broad, splitting, and shift of absorbance bands in their UV-vis spectra. UV-vis spectra of phthalocyanines are typically represented... 

Temp., °C Density, gcm Viscosity, cP Surface tension, dyncm Vapour pressure, mmHg Dielectric constant Refractive index ... 

Following classical EM theory, prior to nineteenth century, individually Gustav Mie and J. C. Maxwell Garnett first showed the theoretical background behind the novel optical property of nanoparticles, that is, SPR, which also depends on the dielectric constant, refractive index, and their individual shape and size. The theories that help modem science to predict the optical property of noble metals are elaborated in the following sections. 

PbO Although it does not form network structures, it can connect Si04 tetrahedrons. It is used for glass with a large dielectric constant, refractive index and specific resistance. As it is easily deoxidized, heat treatment in an atmosphere containing oxygen is necessary. 

Figure 1.3 Dielectric constant, refractive index and reflectivity from the Drude model [Hcop = 10 eV, KT = 0.1 eV).

Figure 1.5 Dielectric constant, refractive index and reflectivity of silver...

In the simplest approaches no solvent structure is required at all, as the relevant properties of the solvent are specified by empirical parameters. Such methods can be quantitatively predictive but as they lack a molecular basis, they provide no insight or understanding of solvation at the miscroscopic level. An approach with a more solid physical basis, which is still computationally inexpensive, treats the solvent as a continuous uniform dielectric material, parametrized by its dielectric constant, refractive index, and the shape of the cavity occupied by the solute molecule. The interaction with the solute polarizes the dielectric which implicitly accounts for the solvent structure. In the most sophisticated approaches the solvent molecules and the resulting intermolecular interactions are treated explicitly. 

The combination of low optical losses over the entire WOC and high thermal, chemical, and mechanical stabilify must therefore be attained by the perfluorination of polyimides. In addition, perfluorination should deorease the dielectric constant, refractive index, and water absorption. These diaracteristics are desirable for optical and opto-electronic applications. This sftufy reports the first synthesis and the properties of perfluorinated polyimides. 

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