The change at the polymers dielectric specifications are a measure for electronic, ionic and molecular polarizability
. These features are being associated with the physical and chemical structure of the polymers.
As was done for the other polymers, the reflectance spectra were normalized to a common reference value (5% at 2200 [cm.sup.-1]) and transformed into molecular polarizability spectra that were then used to calculate dichroic ratios.
The software was slightly modified in-house to allow calculation of the imaginary molecular polarizability function [Phi] from the n and k spectra.
The enhancement is in part attributed to an exceptional increase in the local electromagnetic field (the "electromagnetic mechanism") and to an increase in the molecular polarizability
(the "chemical" or "charge transfer mechanism").[3,4] This enhancement is exploited in the study of electrode processes.
[alpha]-polarizability is molecular polarizability
which reflects molecular cubage and interaction between agent and molecule.
In solutions and melts, where the stresses originate from entropy elasticity, this coefficient scales with the anisotropy of the molecular polarizability of the polymer chain, [DELTA][alpha] (14, 15), as expressed in Eq 2.
For the stress-optical behavior in the glass state at small strains the relation to the molecular polarizability is less well understood, although a correlation to [DELTA][alpha] has been suggested (17, 18).
where [DELTA]C is the change of nuclear coordinate, [alpha] the molecular polarizability
(taken as 10[[Angstrom].sup.3]), and [[alpha].sub.1] the dipole polarizability of the coated sphere.
Thus, 12 theoretical parameters were computed and selected to characterize the processes: the logarithm of octanol/water partition coefficient (log[K.sub.ow]), average molecular polarizability
([alpha]), molecular volume (V), dipole moment ([mu]), energy of the highest occupied molecular orbital ([E.sub.HOMO]), energy of the lowest unoccupied molecular orbital ([E.sub.LUMO]), formal charge on hydroxyl hydrogen atoms ([q.sub.O[H.bar]]), formal charge on hydroxyl oxygen atoms ([q.sub.[O.bar]H]), formal charge on ether oxygen atoms (qo), electrophilicity index ([omega]), harmonic oscillator model of aromaticity index ([I.sub.A]), and the number of bromine atoms ([MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII]) [see also Supplemental Material, Table S1 (doi:10.1289/ehp.090l457)].
where [DELTA][alpha] is anisotropy of molecular polarizability
, [mu] is the resultant dipole moment of the molecule, N is the molecular number density, [DELTA][alpha] is dielectric anisotropy, F is parameter depending on reaction field factor, and [beta] is the angle between the molecular axis and the direction of the off axis.
It is also pointed out to be a measure of the degree of electron localization, molecular polarizability
, and resonance energy .