swelling

The peculiarity of solid bodies of organic origin, in contrast to solid bodies of mineral origin, is that their internal structure is characterized by the presence of two spaces - cellular and intercellular. Such bodies tend to swell upon contact with the extractant. The phenomenon of swelling, during extraction, is always accompanied by the dissolution of target substances contained in the cellular and intercellular space.

The possibility of using hydrogels based on copolymers of polyvinylpyrrolidone with 2 hydroxyethylmethacrylate to saturate them with plant extracts was established. Hydrogel materials were obtained with extracts of Calendula officinalis and Arnica montana. The sorption capacity of the hydrogels regarding the extract data was determined.

The sorption and conducting characteristics of metal-containing hydrogels on the basis of polyvinyl pirrolidone in different mediums are investigated. The typical dependences of electric conductivity change on solvent nature and concentration, pH-medium and applied loading for obtained composition hydrogels are determined. Досліджено сорбційні та електропровідні властивості металовмісних гідрогелів на основі полівінілпіролідону у різних середовищах.

Chitosan films were obtained in the salt form and in the hydroxide form. Films were prepared by dry method of forming. For the production of films chitosan from mycelium biomass waste of fungus Aspergillus Niger was used. The effect of heat treatment on the structure and solubility of chitosan films was studied. It was established that during the heat treatment of the films the process of amidation takes place, which in turn leads to the structure ordering and reduces the solubility of the films.

Diffusion coefficients of organic solvents into tetrafluoroethylene-propylene copolymer structure may be generalized by multiparameter equations. Molar volume and cohesion energy of penetrating liquids are suggested to be determining their values and retarding the process. 

Five series of polyheteroarylenes have been investigated with regard to their physical properties before and after swelling with a supercritical carbon dioxide. The study of the dependence of the glass transition temperature and the free volume of polymers on their conformational rigidity showed that the process of swelling in the supercritical carbon dioxide is influenced by the voluminous side groups and by the high boiling solvent N-methylpyrrolidinone used for preparation of the polymers which facilitates the formation of crosslinks or complexes with the macromolecular chains.