Longitudinal and shear flow birefringence in polyelectrolyte solutions

The dynamics of macromolecules in semidilute solutions of isotactic poly(2- vinylpyridine) in aqueous hydrochloric acid solutions of different concentr ations and bromoform was studied by the method of optical birefringence in longitudinal (elongation) and shear flows. The longitudinal hydrodynamic fi eld produces a stronger action upon macromolecular coils (up to their compl ete unfolding) than does the shear field. Contribution of the kinetic rigid ity of charged polymer chains to the dynamics of macromolecules in solution s in the hydrodynamic fields of both types was estimated. The deforming act ion of the flow upon macromolecules decreases with increasing polymer solut ion concentration, which is interpreted as evidence of the effect of unfold ed chains on the hydrodynamic field structure.