ИСТИНА

In recent years, polymer microgels, especially thermo- and pH-sensitive, attracted the interest of researchers. First of all, this is due to the unique properties of these objects: on the one hand, microgels are able to form a stable to aggregation dispersions. On the other, they are a sufficiently well characterized microscopic object whose size and properties can be governed by changing the external conditions. These properties cause their potential applications - superabsorbents, surface-active stabilizing additives, carriers for drug delivery, photonic crystals. The creation of microgels with nonuniform inner structure and developing ways to control it can open new opportunities for practical use. In our group it was theoretically predicted that shell–corona structure could be formed in the case of interpenetrated microgel particles (IPN microgels) by a pair of initially interpenetrated collapsed and swollen networks [1]. These studies served as a stimulus for the search for the possibility of experimental realization of this idea. The synthetic strategy of the development of IPN microgels on the basis of environment sensitive interpenetrating networks of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAA) (PNIPAM/PAA) was elaborated. IPN microgels were synthesized by in situ copolymerization of acrylic acid and cross-linking agents within PNIPAM microgel particles obtained by thermos-induced precipitation polymerization. Different types of cross-linking agents and cross-linking mechanisms were used to govern the network topology both for NIPAM and AA component. The properties of the obtained gel particles were studied under different environmental conditions by scanning and transmission electron microscopy and dynamic light scattering. [1] Rudyak V.Yu, Gavrilov A.A., Kozunova E.Yu., Chertovich A.V. Soft matter, 2018 (in press).