Collect. Czech. Chem. Commun. 1981, 46, 3018-3026

A simple and exact method for calculating diffusion coefficients from the data of polarization interferometer. Extension to the case of polymers with narrow distribution of molecular weight

Bedřich Porscha and Lars-Olof Sundelöfb

a Institute of Macromolecular Chemistry, Czechoslovak Academy of Sciences, 162 06 Prague 6, Czechoslovakia
b Institute of Inorganic and Physical Chemistry, Faculty of Pharmacy, BMC, Uppsala, Sweden


The simple equation derived previously for calculating the diffusion coefficient and the zero-time correction from the data of the polarization interferometer is shown to be valid not only in the case of binary systems but also for the diffusion of polymer solutes with moderately broad molecular weight distribution and results in a diffusion coefficient, which is an average value of a well-defined type. In addition, it is shown experimentally that the equation is applicable with sufficient accuracy also to the evaluation of diffusion coefficients of polymers having a polydispersity index as high as Mw/Mn = 2.