Lorentz-Lorenz

The sPS has been exploited as sensitive material for fiber optic chemical sensors based on reflectance measurements and aimed to detection of chloroform and toluene in water and air environments48 50. The refractive index of sPS thin films is estimated to be about 1.578. The effect of the analyte sorption in the crystalline domain was modeled as an increase in the material density, which in turn leads to an increase in the refractive index according to the Lorentz-Lorenz law ... 

Lorentz-Lorenz equation, 19 380 Lorivox, molecular formula and structure, 5 92t... 

The refractive index is an important quantity for characterizing the structure of polymers. This is because it depends sensitively on the chemical composition, on the tacticity, and - for oligomeric samples - also on the molecular weight of a macromolecular substance. The refractive indices (determined using the sodium D line) of many polymers are collected in the literature. In order to characterize a molecule s constitution one requires knowledge of the mole refraction, Rg. For isotropic samples, it can be calculated in good approximation by the Lorentz-Lorenz equation ... 

Clausius-Mossotti equation). In this expression, V designates the mole volume and Ae, Be, Cf,... are the first, second, third,... virial dielectric coefficients. A similar expansion exists for the refractive index, n, which is related to the (frequency dependent) dielectric constant as n2 = e (Lorentz-Lorenz equation, [87]). The second virial dielectric coefficient Be may be considered the sum of an orientational and a polarization term, Be = B0r + Bpo, arising from binary interactions, while the second virial refractive coefficient is given by just the polarization term, B = Bpo at high enough frequencies, the orientational component falls off to small values and the difference Be — B may be considered a measurement of the interaction-induced dipole moments [73],... 

Lorentz-Lorenz equation). The A , B ,. .. differ from the Ae, BE,. .. by the absence of the permanent dipole terms. At sufficiently high frequencies, the molecules have not sufficient time to reorient themselves in response to the high-frequency electric field and the contributions of the... 

For white pigments, the hiding power can be expressed through the Lorentz-Lorenz equation (4) as a function of pigment, and medium, nm,... 

To calculate the molar refraction with the Lorentz-Lorenz eq. 4.1.1... 

The Lorentz-Lorenz equation [2] defines the molar refraction, RD, as a function of the refractive index, density, and molar mass ... 

Lorentz-Lorenz as -1—— -, was calculated and the values obtained are also included n2 + 2 d... 

It must be borne in mind that, for glass of a certain composition, the specific refraction according to Lorentz-Lorenz is independent of the temperature of treatment. The results discussed above suggest that this phenomenon may also be connected with polymerization and depolymerization of the glass in question. 

The molar refractivity R of the solvent is derived from the Lorentz-Lorenz expression, and at the D-... 

It should be noted that also the refractive index in eq. (17) will change under pressure. This change can be estimated by the Lorenz local-field model, where the refractive index n is related to the atomic polarizability a p and the density of the material p by the Lorentz-Lorenz relation ... 

In this subsection, the connection is made between the molecular polarizability, a, and the macroscopic dielectric constant, e, or refractive index, n. This relationship, referred to as the Lorentz-Lorenz equation, is derived by considering the immersion of a dielectric material within an electric field, and calculating the resulting polarization from both a macroscopic and molecular point of view. Figure 7.1 shows the two equivalent problems that are analyzed. 

The Lorentz-Lorenz equation can be used directly to model the birefringence of a solution of rigid rod molecules subject to an orienting, external field. Figure 7.2 shows a representative molecule, which is modeled as having a uniaxial polarizability of the form... 

The Lorentz-Lorenz equation can be used to express the components of the refractive index tensor in terms of the polarizability tensor. Recognizing that the birefringence normalized by the mean refractive index is normally very small, ( A/i / 1), it is assumed that Aa /a 1, where the mean polarizability is a = (al + 2oc2)/3 and the polarizability anisotropy is Aa = a1-a2. It is expected that the macroscopic refractive... 

The Onsager function is dependent on the refractive index of the solvent (n). For supercritical C02 the refractive index is dependent on the fluid density and can be calculated from the Lorentz-Lorenz refraction equation ... 

At low atomic densities N, the dielectric response of a medium can be written in the popular Clausius-Mossotti or Lorentz-Lorenz form as a function of N and a coefficient a that includes atomic or molecular polarizability ... 

The dilute limit emerges when a /z3 dilute limit, assume that the dielectric response of dense suspension follows the Lorentz-Lorenz or Clausius-Mossotti relation6 e = [(1 + 2Na/3)/(l - Na/3)] (This is the next approximate form when the number density N is too high to allow the linear relation e = 1 + Na.) Below what density N will this e be effectively linear in polarizability Expand... 

---