PHYSICOCHEMICAL BASIS AND THE PROSPECTS O F USING SOLUBLE INTERPOLYELECTROLYTE COMPLEXES

Interpolyelectrolyte complexes (IPECs) are formed in cooperative react ions involving oppositely charged polyions. Soluble nonstoichiometric IPECs, which are formed in dilute solutions by polyions of different d egrees of polymerization (i.e., contour length), may be considered as specific amphiphilic block copolymers. We discuss the most important p roperties of soluble IPECs, particularly, their participation in react ions of polyion exchange and substitution. The kinetics of these inter polyelectrolyte reactions and their equilibrium are also considered as controlled by the concentration and nature of low-molecular-mass coun terions and the degree of polymerization of the interacting polyions. The disproportionation occurring in IPECs, when pH or ionic strength i s varied, may be used to engineer the enzyme-IPEC systems in which the catalytic activity is mediated by interpolyelectrolyte reactions. The other uses may be the high-efficiency pseudohomogeneous immunodiagnos tics, ''mild'' heparin antagonists, and other promising biomedical app lications.