Abstract
Zero-shear viscosities η0 of aqueous solutions of sodium hyarulonate were compared with the fuzzy-cylinder model theory, a typical theory for semiflexible polymer solutions. Taking into account electrostatic contributions to the chain-stiffness and excluded-volume effect, the theory quantitatively describes the concentration dependence of η0 at molecular weights lower than 106. On the other hand, the theory predicts too strong concentration dependence of η0 at molecular weights higher than 106 at high polymer concentrations. These results indicate that the flexible-chain dynamics (e.g., reptation motion), neglected in the fuzzy-cylinder model theory, are not important in solution viscosity for lower molecular weight sodium hyarulonate, but become important with increasing the molecular weight.
