Dynamic and Electrophoretic Light Scattering of Poly(dimethyldiallylammonium chloride) in Salt-Free Solutions

SYNOPSIS Dynamic and electrophoretic light scattering were used to study the diffusion and electrophoretic mobility of poly(dimethyldiallylammonium chloride) as a function of polymer molecular weight in salt-free solutions. Two relaxation modes characterized as fast diffusion (D,) and slow diffusion (D,) were obtained from dynamic light scattering. Although the slow diffusion coefficient D, strongly depends on molecular weight (M,), the fast diffusion coefficient D, was found to be independent of M, over the range in the study. The fast diffusion was considered as the diffusion of a part of the polymer chain; the slow diffusion was interpreted by multichain diffusion. Electrophoretic light scattering results in the saltfree solution show that the electrophoretic mobility of the polymer is independent of M,. 0 1996 John Wiley & Sons, Inc.