The technique of dynamic light scattering from isorefractive ternary solutions was used to examine the tracer diffusion of linear and star polystyrenes in poly(vinylmethylether) solutions, and of linear polystyrenes in poly(vinylmethylether) gels. A hydrodynamic scaling model is unable to provide an adequate description of the relative solution mobilities of star and linear polymers of equal total molecular weight. In a gel with concentration equal to 0.235 g/cm3, it was found that the tracer diffusivity scales as M-2.9 for linear polymers, where M is the molecular weight, by contrast with the reptation prediction of M-2.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Non-Crystalline Solids|
|Issue number||PART 2|
|State||Published - Jun 2 1991|
Bibliographical noteFunding Information:
The main conclusions from these results are (i) the stronger retardation of star relative to linear polymers with increasing matrix concentration is not consistent with the hydrodynamic scaling model, but is consistent with a crossover to a reptation regime at higher concentrations, and (ii) diffusion through gels is not described by the basic reptation theory. This work was supported by the Donors of the Petroleum Research Fund, administered by the American Chemical Society. Dr M. Sawamoto provided several helpful suggestions with regard to the gel preparation.
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