Principal possibility of using a smart polymer, poly-N-vinylcaprolactam, for immobilization of biopharmaceuticals (antibodies and antigens) in the course of phase transition of a soluble coil into an insoluble globule was demonstrated. A procedure for preparing a hydrosol stable at room temperature in the presence of a stabilizer was examined. The hydrosol obtained, in which the collapsed polymer with the captured antigen acts as a solid support, can be used for agglutination with a complementary antibody, i.e., the immunochemical reaction can be evaluated visually.

It is known that some synthetic polymers can enhance the stability of some proteins including enzymes against thermal denaturation. An important example of such behaviour is poly-N-vinylcaprolactam (PVC), although the mechanism of this phenomenon is not fully understood. This paper deals with this problem with the system PVC-trypsin as an example. PVC is a polymer, which has lower critical solution temperature (LCST) in aqueous solution. It is shown that the rate of enzymatic hydrolysis of a substrate – benzoyl arginine – n-nitroanilide (BAPNA) – with trypsin in aqueous solutions of PVC at 25oC is higher than that in the buffer solution. It is supposed that this effect is a consequence of the complex formation of trypsin with PVC affecting the conformation of the protein and binding of the substrate. The complexation brings about a decrease of the Michaelis constant and an increase of the rate of the biocatalyst interaction with the substrate. It is found that the activity of trypsin depends on the ratio of the enzyme to the substrate. The complexation of trypsin to poly-N-vinylcaprolactam can have influence on the enzymatic activity of the protein at temperatures above LCST, as well as on trypsin trapping in the precipitating polymer. It is noted that, when one determines the enzyme activity by spectral methods, it is necessary to take into account the possibility of complex formation of the polymer with another substance in the reaction system, which can cause errors.

The features of the microwave irradiation effect on trypsin state and changes jn its enzymatic activity in the presence of poly(N-vinyl amides) at various temperatures have been studied. Comparison of the denaturizing effect of the irradiation and of convective heating has revealed, along with the thermal factors, the specific effects of microwave radiation. These effects have been found to affect both protein and polymer molecules, to change their interaction parameters, and thus, to modulate trypsin enzymatic function.

It is known that some synthetic polymers can enhance the stability of some proteins including enzymes against thermal denaturation. An important example of such behaviour is poly-N-vinylcaprolactam (PVC), although the mechanism of this phenomenon is not fully understood. This paper deals with this problem with the system PVC-trypsin as an example. PVC is a polymer, which has lower critical solution temperature (LCST) in aqueous solution. It is shown that the rate of enzymatic hydrolysis of a substrate – benzoyl arginine – n-nitroanilide (BAPNA) – with trypsin in aqueous solutions of PVC at 25ºC is higher than that in the buffer solution. It is supposed that this effect is a consequence of the complex formation of trypsin with PVC affecting the conformation of the protein and binding of the substrate. The complexation brings about a decrease of the Michaelis constant and an increase of the rate of the biocatalyst interaction with the substrate. It is found that the activity of trypsin depends on the ratio of the enzyme to the substrate. The complexation of trypsin to poly-N-vinylcaprolactam can have influence on the enzymatic activity of the protein at temperatures above LCST, as well as on trypsin trapping in the precipitating polymer. It is noted that, when one determines the enzyme activity by spectral methods, it is necessary to take into account the possibility of complex formation of the polymer with another substance in the reaction system, which can cause errors.

Effect of microwave radiation on the polymer-analog reaction of polyvinyl alcohol with low molecular ketone, cyclohexanone, was studied. It is shown that using the energy of this radiation permits to increase considerably the rate of formation of polyketal as compared to the thermal action. It is found that the process of formation of final product may be governed by the nature of solvent. In this case not only the change in solubility must be considered, but the competing absorption of microwave energy by the solvent as well.

The synthesis of composite sorbents from porous silica modified by polyvinyl alcohol was studied. The initial silica retained its porosity after modification which was performed by application of polyvinyl alcohol from aqueous solution. The subsequent thermal or microwave treatment gave nanolayers of water-resistant polyvinyl alcohol. Microwave irradiation was found to be more advantageous than conventional thermal treatment from the viewpoint of the polymeric phase and sorbent parameters. Sorption properties of the resulting sorbents with respect to protein, oligonucleotide, and dyes were studied.

Synthesis of polyvinyl formal from a mixture of polyvinyl alcohol and formaldehyde under microwave irradiation was studied. The syntheses of polyvinyl formal under microwave irradiation and thermal treatment were compared. The yield of polyvinyl formal was examined in relation to the irradiation power, initial component concentration, and reaction time. The polyacetals were characterized by elemental analysis and IR spectroscopy.

The possibility of dehydration (cross-linking) of polyvinyl alcohol upon microwave irradiation of thin polymer films was examined. The properties of polyvinyl alcohol samples treated by convection heating and irradiation were compared. Immobilization of polyvinyl alcohol on polymer matrices by microwave irradiation was studied.

The interaction of microwave radiation with solid polyvinyl alcohol results in the structuring of the polymer accompanied by a change both in the contribution of competitive (both intra- and intermolecular) reactions and in the ratio of reaction products in comparison with the thermal reaction under the same conditions.

The effect of xenon difluoride (XeF2) vapors on the surface properties of the polymer films irradiated by heavy ions and of the nucleopore nanofilters produced from these films is studied. The procedure for modifying nucleopore membranes made of poly(ethylene terephthalate) and polyimide in XeF2 vapors is developed. The hydrophilicity, electrosurface properties, and selectivity of modified membranes are investigated. It is shown that the water contact angle on the membrane surface decreases as a result of modification, and the extent of its change depends on the duration and temperature of membrane treatment. Electrokinetic measurements did not reveal any changes in the surface charge during the modification of the membranes prepared from poly(ethylene terephthalate), but their ion selectivity increased twofold. It is shown that the hydrodynamic diameter of the pores of modified membranes reversibly decreases with an increase in transmembrane pressure. The dislosed effects are explained by the presence of an elastoplastic gel-layer on the surfaces of the membrane and its pores. The gel-layer accumulates considerable surface and bulk charges and is characterized by the high hydraulic resistance hindering the convective ion transport.

The possibility was examined for creating local defective etchable areas in perfluorinated polymeric materials by graft polymerization of methacrylic acid in the areas of latent tracks produced by accelerated heavy ions. The reaction kinetic was studied. With consideration for the nature of the monomer being grafted and the irradiated matrix, methods were developed and used, ensuring significantly increased yield of the grafted polymer and proceeding of graft polymerization in the whole track volume to form a porous structure, i.e., to obtain track membranes.

Contact angles formed by aqueous solutions on PET track membranes with pore sizes ranging from 0.02 to 0.5 mu m were measured. After treatment of the membrane surface with an alkaline buffer or surfactant solutions, after covalent grafting of methacrylic acid (MAA), or gas-phase modification with xenon difluoride, wetting of these surfaces changes, just as their adsorption capacity with respect to proteins (serum albumin) and dyes (rhodamine). The contact angles formed by liquids with different surface tensions were used to estimate the critical surface tension of the membranes.

The features of modification of polyethylene films with xenon difluoride in liquid medium were studied.

Peculiarities of low-temperature alternating copolymerization of sulfur dioxide with 2-methyl-1-pentene initiated by tert-butyl hydroperoxide were studied. Viscous medium is necessary for the formation of high-molecular-mass polysulfone with high yield; moreover, in the limiting case, the solid phase is required. This is achieved when copolymerization is performed in bulk, yielding polysulfone that is insoluble in a mixture of the monomers or at temperatures below the melting point of one of the components of the reaction system (sulfur dioxide). In this case, the effect of initiator is prolonged, bimolecular termination changes to monomolecular, and ''caging'' of macroradicals prevents their mutual diffusion. This leads to a change in the ratio of rate constants of. elementary reactions and, as as a result, affects the overall reaction rate and molecular mass of polysulfone.

The compatibility of poly(alpha-olefinsulfones), having different lengths of side substituents, with cresol-formaldehyde resins in solutions and blocks (films) was studied. As the length of the side chain increases in the series of polysulfones, the intermolecular interaction decreases due to a lower contribution of the cohesive energy of SO2 groups to the total energy. These groups are also responsible for the formation of hydrogen bonds in polysulfone contacting with the resin. Of all the studied pairs of polymers, the compatibility in solutions and films was observed only for the compositions of poly(methyl pentenesulfone) with cresol-formaldehyde resins, mixed in low-polar solvents. The group of solvents favoring the susceptibility also depends on the resin structure. A decrease in the molecular mass of poly(methyl pentenesulfone) leads to increasing compatibility in solutions, although the phase separation is not completely eliminated.

The role of sulfuric acid in the graft copolymerization process was investigated on ozonized organosilicon matrices and polyethylene. It was shown, that the different behavior of sulfuric acid on the reaction rate and the degree of grafting is determined by the ratio of iron II, used as a coinitiator of the reaction, and peroxides which are formed by the activation of the polymeric films. Sulfuric acid increases the graft copolymerization reaction rate if this ratio is close to one and decreases it if there is a surplus of iron. The distribution of the grafted copolymer throughout the matrix volume can be regulated by varying the acidity of the medium.

In a study of graft polymerization of acrylic acid on preozonated siloxane films (dimethylsiloxane-phenylsilsesquioxane block copolymer), it was established that the activation procedure used made it possible to vary the distribution of the grafted polymer in the sample between the two extreme cases: predominantly surface grafting and the preparation of an interpenetrating polymer network. The distribution pattern of the grafted poly(acrylic acid) controls its hydrophilic-hydrophobic balance and its diffusion and strength properties

In a study of graft polymerization of acrylic acid on preozonated siloxane films (dimethylsiloxane-phenylsilsesquioxane block copolymer), it was established that the activation procedure used made it possible to vary the distribution of the grafted polymer in the sample between the two extreme cases: predominantly surface grafting and the preparation of an interpenetrating polymer network. The distribution pattern of the grafted poly(acrylic acid) controls its hydrophilic-hydrophobic balance and its diffusion and strength properties.

For the first time collapse (or decollapse) has been detected for grafted polyacrylic acid macromolecules on an organosilicon elastic matrix. In the process of graft polymerization of acrylic acid on lestosil (a copolymer of dimethylsiloxane and phenylcilsesquioxane) after conversion > 100% the grafted polymer is distributed throughout the matrix, i. e., a system is produced with properties characteristic of an interpenetrating network. At a specific monomer:water ratio in the presence of a solvent with a continuously varying composition the polyacrylic acid macromolecules undergo sudden changes in their size.