Аннотация:Processes of flocculation and stabilization of polysilicic acid (PSA) sols by synthetic linear polycations are describedas reversible interpolyelectrolyte reactions. Flocculation is regarded as a reaction leading to the formation of insoluble polyelectrolyte complexes (PECs), and stabilization is regarded as a reaction leading to the formation of nonstoichiometric water-soluble PECs. The influence of the following factors on the solubility of the resulting PECs has been determined: the degree of conversion in the reaction, the size of the PEC sol particles, and the degree of polymerization of the polycation.