MODIFICATION OF THE ARABINOGALACTAN MATRIX IN THE FORMATION OF METAL–POLYMER NANOBIOCOMPOSITES

Resumo

The paper studies transformations of the macromolecular structure of the polysaccharide arabinogalactan under the action of noble metal nanoparticles that form in its matrix during the formation of metal-containing nanobiocomposites. Exclusion liquid chromatography with complex trichannel detection was used to determine the molecular weight characteristics of arabinogalactan in the composition of metal–polymer nanocomposites self-organized via the specific interaction of the polysaccharide with the surface of zero-valent silver, gold, and platinum nanoparticles that form in an aqueous solution. Transmission electron microscopy was applied to determine the sizes of metal nanoparticles and the arabinogalactan macromolecule, which made it possible to classify the polysaccharide as nanoscale. It is shown that a change in the polydispersity of arabinogalactan occurs due to its redox interaction with noble metal ions and simultaneously due to the occurring alkaline destruction process. It was found that during alkaline depolymerization, which occurs in the synthesis of nanocomposites, the number average molecular weight of arabinogalactan decreases more significantly. The stabilization process for the growing nanoparticles in the formation of the dispersed phase, accompanied by the appearance of new bonds between the polysaccharide and the created in situ silver and gold nanoparticles, causes arabinogalactan macromolecules to aggregate.