ИСТИНА

The interaction of star-shaped polyionic species (polyelectrolyte stars and star-like micelles of ionic amphiphilic diblock copolymers) with the oppositely charged linear homopolyelectrolytes in aqueous media was investigated. It was demonstrated that such interaction (co-assembly) can result in the formation of water-soluble nanosized complex species only if the branched polymeric component is taken in the certain base-molar excess compared to the linear one, otherwise macroscopic phase separation is observed in the system. The star-shaped polyionic component whose ionic groups are incorporated into such complex species in the certain excess plays a lyophilising part, granting to the formed co-assemblies solubility in aqueous media. It was shown that lyophilising strength of the star-shaped polymeric component enhances with the increasing number of arms, this effect becoming especially pronounced with the increasing ionic strength of the surrounding solution. The main feature of the water-soluble interpolyelectrolyte complex particles based on star-shaped polyionic species is their pronounced compartmentalized structure, which results from a distinct non-uniform distribution of chains of the linear polymeric component within the volume occupied by the star-shaped polymeric component. This compartmentalization leads to "core-corona" (polyelectrolyte stars) or "core-shell-corona" (star-like micelles of ionic amphiphilic diblock copolymers) structure of the co-assemblies with a rather compact core (polyelectrolyte stars) or shell (star-like micelles of ionic amphiphilic diblock copolymers) comprising charges of the polymeric components essentially in the ca equimolar ratio and a swollen ionic corona built up from excess arms of the star-shaped polymeric component, which are not coupled to the fragments of the oppositely charged chains of the linear polymeric component. It was further found that a use of double hydrophilic (ionic/non-ionic hydrophilic) diblock copolymers instead of the linear homopolyelectrolytes allows to avoid macroscopic phase separation even at the equimolar ratio of ionic groups of the oppositely charged polymeric components in their aqueous mixtures. The formed complex species are of distinct compartmentalized structure with an interpolyelectrolyte complex core (polyelectrolyte stars) or an interpolyelectrolyte complex shell (star-like micelles of ionic amphiphilic diblock copolymers) and a hydrophilic non-ionic corona, and to impart (via the corona forming blocks) to such co-assemblies some additional properties, which can make them very promising for nowadays rapidly developing nanotechnologies, e.g., as nanocontainers, nanoreactors, etc.