Molecular weight determining from light

The molecular weight obtained by application of Eq. (4.94) to a polydis-perse polymer will be some average over the molecular weight distribution characteristic of the polymer. It can be easily shown tl the molecular weight determined from light scattering measurement is Mw... 

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... 

Figure 3.11. The association of asi-casein B at different values of pH and ionic strength. Molecular weights determined at 20°C using the light-scattering technique. (From Schmidt 1982. Reprinted with permission of Elsevier Applied Science Publishers, Ltd.)...

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