No abstract

This study is devoted to the development of techniques for the formation of polymeric microcapsules (MC) with either liquid or solid core and with the polymer shell containing diverse functional groups on the basis of new reactive functional copolymers (FC). Two approaches to the formation of MC containing FC shell that included the stages of "oil-in-water" or "water-in-oil" dispersion preparation followed by slow extraction of solvents from dispersed phase by dispersive media were examined. FC with the same structure was successfully applied for both "oil-in-water" and "water-in-oil" systems. Spherical MC with the liquid hydrocarbon core demonstrated essential increase in their volume after heating at the temperature exceeding a boiling point of hydrocarbon encapsulated. Presence of reactive groups in the MC shell opens up new opportunity for further tuning the MC properties via their interaction with proper compounds, particularly via graft-polymerisation of diverse vinyl monomers initiated from the MC surface.

Magnetite nanoparticles (Fe3O4 NPs) with peroxide‐containing polymer shell have been synthesized using the method of coprecipitation from the mixture solutions of Fe (II) and Fe (III) salts in the presence of peroxide‐containing copolymer (PCC). Polymer shell presence has been proved by elemental and complex thermal analysis. Synthesized Fe3O4 NPs possess superparamagnetic properties. Their specific saturation magnetization decreases gradually from 65 to 54 A·m2·kg−1 with increasing PCC concentration owing to the surface spin pinning effect caused by a polymer shell. The average sizes of Fe3O4 NPs estimated from the data of XRD analysis and magnetic measurements are in the range of 9–12 nm. The NP sizes determined by the DLS method lie in the range of 150–270 nm; this result is significantly larger than the sizes estimated by the two aforementioned methods evidencing a tendency for Fe3O4 NPs toward self‐association. Cross‐linked composite films based on polyvinyl alcohol have been obtained via radical curing initiated by the PCC shell of nanoparticles. The resulting composite films are magnetically sensitive films with rather high physico‐mechanical properties (tensile strength reaches 48–67 MPa and relative elongation – 4%–21% depending on cross‐linking degree), a priori non‐toxic and biocompatible, which makes them promising materials for various applications.

Combining two different novel techniques, namely Bgrafting from^polymerization and in situ sol-gel synthesis, nanocomposites based on CdS nanocrystals embedded into thin polymer films with diverse structure (either poly(acrylic acid) (PAA) homopolymer or mosaic one composed of polystyrene (PS) and PAA chains) grafted to the solid surface have been obtained. The structure of grafted polymer films as well as the composition of obtained on their basis nanocomposite films were studied and characterized by UV-visible spectroscopy, IR-spectroscopy, scanning electron microscopy, and atomic-force microscopy. Two fractions of CdS nanocrystals with the sizes of~4.5-4.7 and~5.7-6.0 nm formed in polymer films of both types have been found. It has been revealed that the content ratio of these two fractions mostly depends on the structure of polymer films.