Light-scattering 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... 

Figure 10.8 Light-scattering data plotted to give slope-intercept values which can be interpreted in terms of M and B. (a) Polystyrene in methyl ethyl ketone. [From B. A. Brice, M. Halwer, and R. Speiser,/. Opt. Soc. Am. 40 768 (1950), used with permission.] (b) Polystyrene in cyclohexane at temperatures indicated. Units of ordinates are given in Example 10.4. [Reprinted with permission from W. R. Krigbaum and D. K. Carpenter,7. Phys. Chem. 59 1166 (1955), copyright 1955 by the American Chemical Society.]...

Figure 10.12 Light-scattering data in the limit of C2 = 0 plotted according to Eq. (10.89) for cellulose nitrate in acetone. [Data from H. Benoit, A. M. Holtzer, and P. Doty,/. Phys. Chem. 58 635 (1954).]...

Which of the two models for the mode of ATP interaction with myosin do these data support Explain your answer by quantitative interpretation of the light-scattering data. 

Figure 5B. Correlation of right-angle light scatter measured by fluorometry and flow cytometry. The top panel shows flow-cytometric data of side scatter of fixed, stained cells during the time course of stimulation by 1-nM (solid line, solid circles) or 0.01-nH (dashed line, open circle) FLPEP. The bottom panel shows the corresponding right-angle light-scatter data acquired pseudo-simultaneously on live cells in the fluorometer. The flow-cytometric data have been averaged, but the fluorometry data are plotted for both duplicates from one donor. Reproduced with permission from Ref. 27. Copyright 1985 Rockefeller University Press.

Level 2 fit values for sample B8 were obtained from light scattering data. 

With a three-component system, such as a polymer in an aqueous salt solution, preferential adsorption of one component to the polymer can affect the analysis of light-scattering data.199 Such interactions can affect the SRI. Therefore, measurements of the SRI must be made at constant chemical potential. Constant chemical potential is achieved experimentally by dialyzing the solvent and polymer solution to equilibrium through a membrane permeable to the solvent but impermeable to the polymer.199... 

However, certain contradictions can be seen from the data of Tables 1 and 2. Indeed, the molecular weights determined for aqueous solutions of these p- and s-fraclions in the SEC experiments (Table 1) coincided well with the results of light scattering for DMSO solutions (Table 2) but why did the molecular weights differ so considerably from the light scattering data (Table 2) for the solutions of given copolymers in pure water, where, in... 

PMMA) film is quenched by permeation of methyl ethyl ketone (MEK), a good solvent for PMMA. A steady-state MEK concentration profile has been estimated from quenching data with existing sorption and light scattering data. The profile contains all the features of Case II diffusion the Fickian precursor, the solvent front, and the plateau region. However, the solvent front is not so steep as those observed in systems where penetrant diffusion is much slower. 

Equation 3.27 forms the basis for determination of Molecular weight from light scattering data. Like Osmotic pressure measurements, it is essential to consider the non-ideality of solutions and the concentration dependence. Following Debye, eq. 3.27 gets modified to... 

P. Chylek, V. Ramaswamy, A. Ashkin, and J. M. Dziedzic, Simultaneous determination of refractive index and size of spherical dielectric particles from light scattering data, Appl. Opt. 22, 2302-2307 (1983). 

If the particle is a sphere of known density p, light-scattering data can be used to obtain the radius, and then the mass is given by... 

The intrinsic viscosity of PVB is shown as a function of solvent composition for various MIBK/MeOH mixtures in Figure 6. Since [ij] increases with a (see Equation 8), the higher [ly] the better the solvent. Apparently, most mixtures of MIBK and MeOH are better solvents for PVB than either pure solvent. Based on Figure 6, PVB should have a weak selective adsorption of MIBK in a 1 1 solvent mixture and weak adsorption of MeOH in a 3 1 MIBK/MeOH solvent mix. These predictions are in accord with light scattering data discussed previously. The intrinsic viscosity data is also consistent with the second virial coefficient data in Table II in indicating that the 1 1 and 3 1 MIBK/MeOH mixtures are nearly equally good solvents for PVB, the 9 1 mix is a worse solvent, but still better than pure MeOH. 

Figure 3. KINSIM/FITSIM applied to analysis of actin polymerization, showing actual light scattering data points and kinetic simulations (solid lines).

Methods of Data Analysis 4.1 Light scattering data. 

Fig. 1.5.6 Polarization ratio of the scattered lighi against the angle for the unreacted titanium (IV) ethoxide, Ti(OEt)4, aerosol generated at 101°C, and the same aerosol reacted with water vapor at three distances (X) corresponding to 13, 39, and 340 ms reaction time. On the right-hand side are given calculated modal radii and refractive indices from the light scattering data. The bottom values are for the solid titania. (From Ref. 37.)...

Mori et al. s results for three PBLG samples in m-cresol. For every sample, Dr decreases monotonically with increasing c, in a way resembling the simulation results shown in Fig. 16b. These Dr data, as well as the dynamic light scattering data, will be compared with Eqs. (50)- (52) in Sect. 8 together with zero-shear viscosity data. 

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