Dynamic Light Scattering Experiment

Dynamic light-scattering experiments or the analysis of some physicochemical properties have shown that finite amounts of formamide, A-methylformamide, AA-dimethyl-formamide, ethylene glycol, glycerol, acetonitrile, methanol, and 1,2 propanediol can be entrapped within the micellar core of AOT-reversed micelles [33-36], The encapsulation of formamide and A-methylformamide nanoclusters in AOT-reversed micelles involves a significant breakage of the H-bond network characterizing their structure in the pure state. Moreover, from solvation dynamics measurements it was deduced that the intramicellar formamide is nearly completely immobilized [34,35],... 

Additional insights into the dynamics and structure of bimodal elastomers have been obtained by dynamic light-scattering experiments [129], neutron scattering experiments [130] and calculations [131], dual cross-linking system experiments [132], non-affine swelling [133], and the computer simulations already mentioned. 

The incorporation of non-Gaussian effects in the Rouse theory can only be accomplished in an approximate way. For instance, the optimized Rouse-Zimm local dynamics approach has been applied by Guenza et al. [55] for linear and star chains. They were able to obtain correlation times and results related to dynamic light scattering experiments as the dynamic structure factor and its first cumulant [88]. A similar approach has also been applied by Ganazzoli et al. [87] for viscosity calculations. They obtained the generalized ZK results for ratio g already discussed. 

Antibiotic Mg complex induced alteration in the ultrastructural changes in the native and HI depleted chromatin were monitored by thermal melting analysis, polyacrylamide gel mobility assay, dynamic light scattering experiments and transmission electron microscopic studies. Micrococcal nuclease digestion is the biochemical probe to assess the accessibility of the antibiotic Mg + complexes to nucleosomal DNA. 

We have identified three diffusion coefficients. These are the self-translational diffusion coefficient D, cooperative diffusion coefficient Dc, and the coupled diffussion coefficient fly. fl is the cooperative diffusion coefficient in the absence of any electrostatic coupling between polyelectrolyte and other ions in the system, fly is the cooperative diffusion coefficient accounting for the coupling between various ions. For neutral polymers, fly and Dc are identical. Furthermore, we identify fly as the fast diffusion coefficient as measured in dynamic light scattering experiments. The fourth diffusion coefficient is the slow diffusion coefficient fl discussed in the Introduction. A satisfactory theory of flj is not yet available. 

Therefore we expect Df, identified as the fast diffusion coefficient measured in dynamic light-scattering experiments, in infinitely dilute polyelectrolyte solutions to be very high at low salt concentrations and to decrease to self-diffusion coefficient D KRg 1) as the salt concentration is increased. The above result for KRg 1 limit is analogous to the Nernst-Hartley equation reported in Ref. 33. The theory described here accounts for stmctural correlations inside poly electrolyte chains. 

In a dynamic light scattering experiment, the measured intensity-intensity time-correlation function g<2)(tc), where tc is the delay time, is related to the normalized electric field correlation function g(1)frc), representative of the motion of the particles, by the Siegert relation [18] ... 

Table 1. Droplet diameter measured by Dynamic Light Scattering experiments at 90° and distribution limits extracted from a multi-exponential analysis (10% brine in pure span 80)...

While complete ring closure is indicated by mass spectral and NMR analysis, characterization of 5 by X-ray and neutron scattering [133], and by dynamic light scattering experiments [134] suggested this polymer has... 

Preliminary dynamic light scattering experiments for ionomers in THF show that the measured correlation function deviates from a single-exponential function. This may be due to the polydlsperslty of molecular aggregates of ionomers, since the aggregation occurs randomly. 

It was checked by dynamic light scattering experiments, that in our water medium, boehmite partieles have a monodisperse size, which hydrodynamic radius is centered around 20 nm [5]. Therefore, we have chosen boehmite geometrical surface to describe our systems. 

Figure 2.17 Intensity Z versus time t for a typical dynamic light scattering experiment. The signal fluctuates due to density fluctuations in the sample [80].

Dynamic light scattering experiments were conducted for sulfonated PS ionomers in DMF [87]. CONTIN analysis of the decay rate generally indicates the existence of two decay modes. Both modes have a q2 dependence and therefore are diffusive processes. This is similar to that observed for salt-free polyelectrolytes in aqueous solution [76-79],... 

In dynamic light scattering experiments the motion of a particle with constant velocity results in a Doppler shift in the frequency spectrum. In a heterodyne experiment (mixing of a small portion of the unscattered light with the scattered one on the photomultiplier) this shift Aw can be directly determined from the power spectrum [98], providing the electrophoretic mobility by the simple relation... 

VII. Dynamic Light-Scattering Experiments from Free Films.376... 

VII. DYNAMIC LIGHT-SCATTERING EXPERIMENTS FROM FREE FILMS... 

Bulk Solution Properties and Equilibrium Thicknesses (Aj) and Results of Dynamic Light-Scattering Experiments for the Two Systems Described in Text... 

Describe how viscosity and dynamic light scattering experiments might give information about molecular size... 

The assumption of no interaetion between the rotating molecules is not correet in a dense dipolar liquid where the moleeules may possess a dipole moment in addition to being polarizable. In sueh a situation, dynamic light-scattering experiments measure the eolleetive property. The polarizability can be expanded in terms of spherieal harmonies and, for a moleeule of ellipsoidal or cylindrieal symmetry, the only terms that appear are Y2m. So the dynamic quantity is T2m(k,0 and the eorrelation funetions, C2m(k, t), are defined as... 

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