Self-diffusion and sedimentation of dextran in concentrated solutions

Frictional coefficients for dextran in water have been evaluated from (i) self-diffusion coefficients determined by pulsed-field-gradient NMR, and (ii) sedimentation coefficients in concentrated solutions. The results show that these frictional coefficients are only equal at infinite dilution and that f_s increases more rapidly than f_D^* as the concentration increases.