Single-chain dynamics general properties

4 being the solute volume fraction and O the osmotic pressure, in the sense that a calculation of either Ds or Dm from measurements of H Dm or Ds, respectively, gives reasonable agreement with experiment. Zettl, et al. also found that PCS on concentrated solutions shows a second, fast mode, whose nominal diffusion coefficient closely matches they advance a theoretical explanation. 

The objective here is to identify features characteristic of single-chain diffusion by an ideal polymer in solution, following which it becomes possible to identify specific chemical effects in particular series of measurements. As discussed below first, the functional forms of the concentration and molecular weight dependences of the self- and tracer diffusion coefficients are found. Second, having found that Ds almost always follows a particular functional form, correlations of the function s phenomenological parameters with other polymer properties are examined. Third, for papers in which diffusion coefficients were reported for a series of homologous polymers, a joint function of matrix concentration and matrix and probe molecular weights is found to describe Ds. Fourth, a few exceptional cases are considered. These cases show that power-law behavior can be identified when it is actually present. Finally, correlations between Ds, rj, and Cp are noted. In more detail  

The observation that Eqs. 8.1 and 8.2 describe experimental data very well does not prove that they are physically significant. Several different mathematical forms may describe the same results to within the actual experimental error. However, when the data are uniformly not described by a mathematical form, to well beyond 

Second, scaling parameters a and v are systematically correlated with the matrix and prohe molecular weights. In particular  

The value of a might plausibly alternatively be correlated with the polymer s size, a size estimator being provided by Do, which varies between systems in part because T and solvent viscosity are not always the same. A nominal chain hydrodynamic radius 

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General properties single-chain dynamics approximation by a generalized Stokes-Einstein equation... 

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