The polyelectrolyte complex formed from the polyanion and polycation was studied by turbidimetry

static and electrophoretic light scattering

and elementary analysis. Sodium salts of polyacrylate (PA) and heparin (Hep) were chosen as the polyanion

and hydrochloric salts of poly(vinyl amine) (PVA) and chitosan (Chts) as the polycation. Although these vinyl polymers and polysaccharides have remarkably different backbone chemical structures and linear charge densities

all the four combinations PA-PVA

PA-Chts

Hep-PVA

and Hep-Chts provide almost stoichiometric polyelectrolyte complexes which are slightly charged owing to the adsorption of the excess polyelectrolyte component onto the neutral complex. The charges stabilize the complex colloids in aqueous solution of a non-stoichiometric mixture

and the aggregation number of the complex colloids increases with approaching to the stoichiometric mixing ratio. The mixing ratio dependence of the aggregation number for the four complexes is explained by the model proposed in the previous study.