VISCOMETRIC BEHAVIOR OF DILUTE POLYELECTROLYTES - ROLE OF ELECTROSTATIC INTERACTIONS

This paper deals with the investigation of the electroviscous effects on sodium hyaluronate aqueous solutions. Dilution of a polyelectrolyte in water or low salt concentration solvent gives a reduced viscosity passing through a maximum whose position corresponds to a polymer conc entration directly related to the ionic concentration. Independently o f the molecular weight when isoionic dilution is performed, the confor mation is preserved and the intrinsic viscosity corresponding to the a dopted ionic concentration is obtained as soon as the concentration ra nge corresponds to the dilute domain. At end the model previously prop osed to take into account the role of the electrostatic interactions o n the conformation is adopted to interpret, with a good agreement, the data of intrinsic viscosity versus ionic concentration.