SYNTHESIS OF SELENIUM NANOPARTICLES STABILIZED WITH POLYVINYLPYRROLIDONE

In recent years, there has been an increase in publications devoted to the creation of new materials based on self-organized nanostructured composites of specified sizes and maintaining their stability for a long time. Nanosystems based on nanoselenium are of particular interest, as it is vital for humans and animals. However, in many regions of Russia, selenium deficiency is observed in agricultural soils. The least toxic and bioavailable is nanoscale selenium. Currently, the most widely used methods of chemical reduction of selenium ions in solutions using ascorbic acid, glucose, dithiourea and sulfur-containing amino acids. And high-molecular compounds are used as stabilizers, both natural (alginate, chitosan, arabinogalactan) and synthetic (polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone). The aim of this work was the synthesis of self-organized selenium nanoparticles in a polyvinylpyrrolidone (PVP) matrix with different molecular weights. To establish the effect of the ratio of selenium–PVP components on the formation process, spectral and structural-morphological characteristics of selenium nanocomposites, as well as on their aggregative resistance to the environment. Selenium nanoparticles were obtained by chemical reduction of sodium selenite with L-cysteine, in the presence of PVP grade «Kollidon® 30» (K-30) and grade «Kollidon® 90 F» (K-90). The viscometric method was used to determine the medium-viscosity molecular weights of two PVP samples (grades K-30 and K-90). The control of the aggregate stability of the obtained selenium nanoparticles was carried out by spectrophotometric and potentiometric methods. As a result of this work, new bioactive systems based on selenium nanoparticles and a nonionic polymer – polyvinylpyrrolidone with different molecular weights were synthesized. The formation of selenium nanoparticles in the zero-valence state in aqueous solutions of PVP, which are sufficiently stable for 4–5 weeks, has been established by UV spectroscopy. It was found that the concentration and molecular weight of PVP do not significantly affect the structure and size of selenium nanoparticles, but affect the aggregate stability and «lifetime» of nanosystems.