The object of this investigation of molecular diffusion in aqueous polymer solutions was to study the effect of solute concentration on the differential diffusion coefficient and also to study the effect of polymer concentration on the mean integral diffusion coefficient. For this purpose a microinterferometric method was used. Two non-ionic, water soluble polymers, Carboxymethylcellulose (CMC) and Carboxypolymethylene (Carbopol), were used in the study with D-Glucose as a solute.
The differential diffusion coefficient was found to increase with increases in solute concentration in all cases. For CMC, the integral diffusion coefficient at first decreased with increasing polymer concentration but became constant after a certain value of polymer concentration has been reached. For Carbopol, the integral diffusion coefficient decreased with increasing polymer concentration.
It appears that the Wilke-Chang correlation may approximately predict the differential diffusivity of the solute at very low solute concentrations in the polymeric solutions with a probable error of ± 10% --Abstract, page ii
