Dilute solution behavior of a cationic polyelectrolyte

Dilute solution behavior of a cationic polyelectrolyte was studied with respect to acetic acid concentration using chitosan. The reduced viscosity, ηsp/C, of chitsan solutions increases with a decrease in the polymer concentration. For a given polyelectrolyte concentration, the specific viscosity is higher at lower acid (acetic) concentration, indicating the expansion of the polyelectrolyte chain due to electrostatic repulsion as a result of the interactions between chitosan and the solvent. The relationship between intrinsic viscosity [η]∞ and acetic acid concentration suggests no conformational transition of the chitosan molecules and possible formation of intramolecular hydrogen bonds during the shrinking of the hydrodynamic domain of the polyions.