Depolarized dynamic light scattering

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).

Significantly smaller values of the hydrodynamic radius in the range a = 10.0 0.3 A were recently obtained for 8-, 12- and 20-bp synthetic DNAs by depolarized dynamic light scattering(225) (DDLS) and for 12- and 36-bp synthetic DNAs by FPA.(2 6) The origin of the difference in hydrodynamic radius between these short synthetic DNAs, which contain 83—100% GC, and the restriction fragments studied previously is not yet known, but is currently under investigation. 

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... 

The same plot constructed with the Dr/Dr0 data from depolarized dynamic light scattering is shown in Fig. 27b. The data points of Kubota and Chu [131] for dimethylformamide solutions come closer to the theoretical curve than those... 

Depolarized Dynamic Light Scattering and Dielectric Relaxation are related to the the multimolecular orientation correlation function... 

In a depolarized dynamic light scattering (DDLS) experiment in the VH configuration, we observe the cross-polarized component of the scattering field produced by a vertically polarized incident beam with respect to the scattering plane. In this case, the purely translational... 

DDLS depolarized dynamic light scattering FEG-SEM field emission gun scanning electron microscopy SANS small angle neutron scattering... 

Viscosity measurements of solutions of low-molecular weight PBO in chlorosulfonic acid and other solvents yielded a Mark-Houwink exponent of 1.85, which is very close to the value expected for a rodlike polymer [45]. Depolarized dynamic light scattering of PBT solutions in chlorosulfonic acid resulted in a persistence length of 64 nm, which is one of the highest persistence lengths known when compared with those of other rigid-rod polymers [58]. 

Badaire S, Poulin P, Maugrey M and Zakri C (2004) In situ measurements of nanotubes dimensions in suspensions by depolarized dynamic light scattering, Langmuir 20 10367-10370. 

At first, an overview of the experimental methods which are suitable to characterize the CNT aggregation state in general, and thus are suitable to monitor CNT debundling in aqueous medium and in presence of surfactant, will be reviewed. Three main streams will be presented (i) "direct imaging of the CNT dispersions by m icroscopic techniques (ii] spectroscopic techniques, such as Raman spectroscopy, which exploit the difference in electronic properties between bundled and individualized CNTs and (iii] depolarized dynamic light scattering which is commonly used to characterize colloidal systems. 

Depolarized dynamic light scattering is based on the analysis of time fluctuations in the scattered light intensity due to Brownian motion of optically anisotropic particles suspended in a liquid medium. ... 

Stepanek P, Ahndal K and Lodge T P (1997) Polarized and depolarized dynamic light scattering from a block copolymer melt, J Polym Sci Part B Polym Phys Ed 35 1643-1648. 

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