Light scattering method Zimm plots

Kinetic Light-Scattering Method. Isochronous Interpolation. When high-activity samples of endocellulase are used, the reaction proceeds so quickly that, since the measurements of scattered intensity at different angles are not performed at the same extent of reaction, the extrapolations to zero angle and the subsequent calculations are erroneous. For this reason Kratochvil et al. (27) have proposed an isochronous interpolation method, whereby the Kc/Re values are plotted against sin21 (0/2) + kft. As in the double-extrapolation method of Zimm, the value of k may be chosen arbitrarily in order to space the experimental data. 

A graphical method, proposed by Zimm (thus tenned the Zinnn plot), can be used to perfomi this double extrapolation to detemiine the molecular weight, the radius of gyration and the second virial coefficient. An example of a Zinnn plot is shown in figure Bl.9.6 where the light scattering data from a solution of poly... 

Dynamic light scattering, coupled with modern computer programs and auxiliary equipment, automatically graphs Zimm plots and computes Mw, Rg, , Cl, and flow rates. New techniques have expanded the method to the semidilute and concentrated regimes (Barth and Sun, 1991). 

Fig. 2.—Typical Plot of Light-scattering Data by the Method of Zimm. (For description of the coordinates, see the text.)...

Because scattering varies with different angles from the main beam of light, the results must be extrapolated to zero concentration and zero angle of scattering. This is done simultaneously by a method developed by Zimm. A typical Zimm plot is illustrated in Fig. 1.9. 

Typical light-scattering data for polystyrene in butanone are plotted in Fig. 1.59 in a method which was suggested originally by Zimm [20,21]. The abscissa is... 

We also proposed a novel light scattering intensity analysis mefood, which is, valid up to about 50% hydrated micellar volume fraction. The new light scattering intensity analysis method significantly extends the concentration range of the traditional Zimm Plot (24). Its simplicity makes it useful also as a fingerprint to detect phase transitions. 

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