ON THE CORRELATION BETWEEN THE VISCOSITY OF PARTIALLY HYDROLYZED POLYACRYLAMIDE SOLUTION AND THE DIFFUSION-COEFFICIENT IN THE SEMIDILUTE CONCENTRATION REGIME

The solution viscosity of neutral polyacrylamide (PAM), the partially hydrolyzed polyacrylamide (70% HPAM), and polyacrylic acid (PAA) were measured concurrently with the apparent diffusion coefficient in the d ilute and semidilute concentration regimes. We identified the scaling relation eta - eta(s) = A/D in the semidilute regime, where eta is the solution viscosity, eta(s) is the solvent viscosity, D is the coeffic ient of the slow diffusion mode obtained from dynamic light scattering , and A is a prefactor found to have a unique value of similar to 1.0 x 10(-8) cP cm(2)/s. The scaling relation as well as the prefactor are independent of the the ionic strength, the solvent quality, the molec ular weight, the charge density, the polyelectrolyte, and salt concent rations. For the neutral PAM, the product [eta - eta(s)]D is proportio nal to the polyelectrolyte concentration c(p), consistent with Rouse t heory and previous experimental findings.