Birefringence electrical

Tsvetkov, V. and Andreeva, L. Flow and Electric Birefringence in Rigid-Chain Polymer Solutions. Vol. 39, pp. 95-207. 

The addition of salts modifies the composition of the layer of charges at the micellar interface of ionic surfactants, reducing the static dielectric constant of the system [129,130]. Moreover, addition of an electrolyte (NaCl or CaCli) to water-containing AOT-reversed micelles leads to a marked decrease in the maximal solubihty of water, in the viscosity, and in the electrical birefringence relaxation time [131],... 

Tinland, B., Pernodet, N., and Weill, G., Field and pore size dependence of the electrophoretic mobility of DNA A combination of fluorescence recovery after photobleaching and electric birefringence measurements, Electrophoresis, 17, 1046, 1996. 

The physical properties (7-10) of our E-V copolymers are sensitive to their microstructures. Both solution (Kerr effect or electrical birefringence) and solid-state (crystallinity, glass-transitions, blend compatibility, etc.) properties depend on the detailed microstructures of E-V copolymers, such as comonomer and stereosequence distribution. I3C NMR analysis (2) of E-V copolymers yields microstructural information up to and including the comonomer triad level. However, properties such as crystallinity depend on E-V microstructure on a scale larger than comonomer triads. 

Figure 4.1. Time scales for rotational motions of long DNAs that contribute to the relaxation of the optical anisotropy r(t). Experimental methods used to study these motions in different time ranges are also indicated along with the authors and dates of some early work in each case. FPA, Fluorescence polarization anisotropy (Refs. 15, 18-20, and 87) TPD, transient photodichroism (Refs. 28 and 62) TEB, transient electric birefringence (Refs. 26 and 27) DDLS, depolarized dynamic light scattering (Ref. 116) TED, transient electric dichroism (Refs. 25, 115, and 130) Microscopy, time-resolved fluorescent microscopy (Ref. 176).

Dynamic Light Scattering and Transient Electric Birefringence Study of Poly(vinyI chloride) Micrc els... 

In this study, has been investigated by means of quasi-elastic light scattering and transient electric birefringence the effect of the quenching concentration on the structure of the PVC aggregates as well as the thermal stability of these aggregates. 

Table I. Transient electric birefringence parameters for PVC solutions at C = 10 g cm...

A (1.6). The filled symbols correspond to the Dq values calculated from the transient electric birefringence results (cf. text). 

We have also reported on the ordinate axis of Fig.3 the values of the translational diffusion coefficient calculated from radius values measured by transient electric birefringence, using ... 

Analysis of polyelectrolytes in the semi-dilute regime is even more complicated as a result of inter-molecular interactions. It has been established, via dynamic light-scattering and time-dependent electric birefringence measurements, that the behavior of polyelectrolytes is qualitatively different in dilute and semi-dilute regimes. The qualitative behavior of osmotic pressure has been described by a power-law relationship, but no theory approaching quantitative description is available. 

Data of Dr were obtained for low molecular weight poly (y-benzyl-L-gluta-mate) (PBLG) samples in isotropic solutions by two methods. Mori et al. [129] used dynamic electric birefringence, while Zero and Pecora [130] and Kubota and Chu [131] applied depolarized dynamic light scattering. Figure 18 shows... 

Fig. 18. Double logarithmic plot of Dr/Dr0 vs L3c from dynamic electric birefringence data [129]. Curves, eye guide...

Fig. 27a, b. Comparison of Eq. (50) with the Dr data for isotropic solutions of relatively short PBLG samples in the plot of Dr/Dr0 vs X a data from dynamic electric birefringence by Mori et al. [129] (the same data as shown in Fig. 18) b data from dynamic light scattering by Kubota and Chu [131] and Zero and Pecora [130], The solid curve, theoretical values predicted by Eq. (50)... 

The rotational diffusion constant in water at 25° and neutral pH as measured by electric birefringence (258) is 230 X 105 sec-1 or 0.73 X HT8 sec as a relaxation time. For a hydrodynamic ellipsoid of dimensions 66 X 22 A and a molecular weight of 14,000, the calculated relaxation tilde is 0.72 X 10-8 sec. However, the apparent asymmetry of the molecule from the X-ray structure corresponds to an axial ratio of no more than 2 1 rather than 3 1. 

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