The peroxidic modification of the surface of a dispersed phase by heterofunctional polymeric pero... more The peroxidic modification of the surface of a dispersed phase by heterofunctional polymeric peroxides (HFPPs) is discussed. HFPPs are carbochain polymers which have statistically located peroxidic (-00-) and high-polar functional (carboxylic) groups along the main chain. Sharp differences in the polarity of these groups endowes HFPP macromolecules with the capability of interfacial adsorption in various polymeric colloidal systems. The reactions of the functional groups provide chemical bonding of the macromolecules to the interfacial surface. As a consequence of such physical adsorption or chemisorption of HFPP, peroxidation of filler surfaces and the localization of active-00-groups on the interface may be effected. In addition, such-00-groups can facilitate the grafting of matrix polymer macromolecules to the surface of the dispersed phase. Such grafting reactions can be carried out during polymer filling, the curing processes of composites or the vulcanization of a rubber mixture. It has been shown that an improvement in the physical and mechanical properties of polymers and an increase in the e1ectroconductivity and heat conductivity of filled compositions is achieved on modification by HFPP.
Chemistry, Technology and Application of Substances, 2019
Silica nanoparticles with functional polymer shell based on reactive peroxide-containing copolyme... more Silica nanoparticles with functional polymer shell based on reactive peroxide-containing copolymers were synthesized via sol-gel method. Unimodal nanoparticles of spherical shell with the size of 190-350 nm and low polydispersity index were obtained. The influence of copolymer nature and concentration, catalyst concentration, onto process kinetics and nanoparticle size was studied. The formation of functional polymeric shell on the surface of silica nanoparticles was proved using the methods of gas-liquid chromatography and complex thermal analysis.
This paper describes the in-situ synthesis in polymer films of the nanocrystals (NCs) of the tern... more This paper describes the in-situ synthesis in polymer films of the nanocrystals (NCs) of the ternary semiconductors Cd1-xCuxS and Cd1-xZnxS as well as the results of investigations of their structure and optical properties. It has been established that, in case of Cd1-xCuxS in a large range of Cu to Cd ratios, the hexagonal structure is dominating in NCs synthesized, while in case of Cd1-xZnxS the dominating crystalline structure of NCs corresponds to cubic structure of CdS. However in both cases formation of separate phases of either CdS and CuS or CdS and ZnS has not been revealed, confirming formation of ternary semiconductor compounds. It has been revealed an opposite effect of increasing concentrations of Cu and Zn cations in ternary compounds on intensity of an impurity photoluminescence, for the former this intensity decreases, but for latter it increases. The possible reasons for these phenomena are discussed.
Нанокристали CdS синтезовано за T = 313 К безпосередньо в полiмернiй матрицi. Дослiджено спектри ... more Нанокристали CdS синтезовано за T = 313 К безпосередньо в полiмернiй матрицi. Дослiджено спектри фотолюмiнесценцiї виготовлених зразкiв залежно вiд температури та iнтенсивностi оптичного збудження. Запропоновано механiзми випромiнювальної рекомбiнацiї нерiвноважних носiїв заряду, що вiдповiдають за окремi смуги фотолюмiнесценцiї нанокристалiв CdS.
Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted ... more Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted great interest in tissue engineering and biofabrication. In these fields, new materials and approaches to prepare hydrogels without using toxic starting materials or materials that decompose into toxic compounds remain to be sought after. Here, we report the crosslinking of commercial, unfunctionalized hydrophilic poly(2-ethyl-2-oxazoline) using peroxide copolymers in their melt. The influence of temperature, peroxide copolymer concentration, and duration of the crosslinking process has been investigated. The method allows to create hydrogels from unfunctionalized polymers in their melt and to control the mechanical properties of the resulting materials. The design of hydrogels with a suitable mechanical performance is of crucial importance in many existing and potential applications of soft materials, including medical applications.
Hìmìâ, tehnologìâ rečovin ta ïh zastosuvannâ, Nov 1, 2021
Cross-linked polymer films based on polyvinyl alcohol and polyacrylamide have been prepared via r... more Cross-linked polymer films based on polyvinyl alcohol and polyacrylamide have been prepared via radical cross-linking initiated by peroxide containing reactive copolymers. The influence of temperature, nature and concentration of cross-linking agents onto gel-fraction value and properties of polymer films has been studied. Obtained cross-linked polymer films are characterized by improved physico-mechanical properties that depend on the content of peroxide containing copolymer and on the presence of additional cross-linking agent.
Polymeric microcapsules with paraffin core containing magnetite nanoparticles modified by oleic a... more Polymeric microcapsules with paraffin core containing magnetite nanoparticles modified by oleic acid and functional polymeric shell were synthesized using the technique of "extraction-coacervation" microencapsulation. The influence of process parameters onto colloidal chemical properties (size, dispersity index, surface porosity) of synthesized microcapsules was studied. It was shown that the use of heterofunctional copolymer as microcapsule shell allows the possibility of irreversible immobilization of α- amylase and provide its participation in the reaction of starch catalytic decomposition.
Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted ... more Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted great interest in tissue engineering and biofabrication. In these fields, new materials and approaches to prepare hydrogels without using toxic starting materials or materials that decompose into toxic compounds remain to be sought after. Here, we report the crosslinking of commercial, unfunctionalized hydrophilic poly(2-ethyl-2-oxazoline) using peroxide copolymers in their melt. The influence of temperature, peroxide copolymer concentration and duration of the crosslinking process has been investigated. The method allows to create hydrogels from unfunctionalized polymers in their melt and to control the mechanical properties of the resulting materials. The design of hydrogels with a suitable mechanical performance is of crucial importance in many existing and potential applications of soft materials, including medical applications.
Chemistry, Technology and Application of Substances, 2020
Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mi... more Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mineral nanoparticles of hydroxyapatite and silica have been obtained via radical cross- linking initiated by peroxide containing reactive copolymers. The influence of temperature and additional cross-linking agents on the peculiarities of curing process has been studied. The obtained results reveal that at high temperatures the dependence of film gel-fraction values on time has the extremal character. Obtained cross-linked nanocomposite films are characterized by improved physico-mechanical properties that depend on the nature of mineral nanoparticles, content of peroxide containing copolymer and on the presence of additional cross-linking agent.
The peroxidic modification of the surface of a dispersed phase by heterofunctional polymeric pero... more The peroxidic modification of the surface of a dispersed phase by heterofunctional polymeric peroxides (HFPPs) is discussed. HFPPs are carbochain polymers which have statistically located peroxidic (-00-) and high-polar functional (carboxylic) groups along the main chain. Sharp differences in the polarity of these groups endowes HFPP macromolecules with the capability of interfacial adsorption in various polymeric colloidal systems. The reactions of the functional groups provide chemical bonding of the macromolecules to the interfacial surface. As a consequence of such physical adsorption or chemisorption of HFPP, peroxidation of filler surfaces and the localization of active-00-groups on the interface may be effected. In addition, such-00-groups can facilitate the grafting of matrix polymer macromolecules to the surface of the dispersed phase. Such grafting reactions can be carried out during polymer filling, the curing processes of composites or the vulcanization of a rubber mixture. It has been shown that an improvement in the physical and mechanical properties of polymers and an increase in the e1ectroconductivity and heat conductivity of filled compositions is achieved on modification by HFPP.
Chemistry, Technology and Application of Substances, 2019
Silica nanoparticles with functional polymer shell based on reactive peroxide-containing copolyme... more Silica nanoparticles with functional polymer shell based on reactive peroxide-containing copolymers were synthesized via sol-gel method. Unimodal nanoparticles of spherical shell with the size of 190-350 nm and low polydispersity index were obtained. The influence of copolymer nature and concentration, catalyst concentration, onto process kinetics and nanoparticle size was studied. The formation of functional polymeric shell on the surface of silica nanoparticles was proved using the methods of gas-liquid chromatography and complex thermal analysis.
This paper describes the in-situ synthesis in polymer films of the nanocrystals (NCs) of the tern... more This paper describes the in-situ synthesis in polymer films of the nanocrystals (NCs) of the ternary semiconductors Cd1-xCuxS and Cd1-xZnxS as well as the results of investigations of their structure and optical properties. It has been established that, in case of Cd1-xCuxS in a large range of Cu to Cd ratios, the hexagonal structure is dominating in NCs synthesized, while in case of Cd1-xZnxS the dominating crystalline structure of NCs corresponds to cubic structure of CdS. However in both cases formation of separate phases of either CdS and CuS or CdS and ZnS has not been revealed, confirming formation of ternary semiconductor compounds. It has been revealed an opposite effect of increasing concentrations of Cu and Zn cations in ternary compounds on intensity of an impurity photoluminescence, for the former this intensity decreases, but for latter it increases. The possible reasons for these phenomena are discussed.
Нанокристали CdS синтезовано за T = 313 К безпосередньо в полiмернiй матрицi. Дослiджено спектри ... more Нанокристали CdS синтезовано за T = 313 К безпосередньо в полiмернiй матрицi. Дослiджено спектри фотолюмiнесценцiї виготовлених зразкiв залежно вiд температури та iнтенсивностi оптичного збудження. Запропоновано механiзми випромiнювальної рекомбiнацiї нерiвноважних носiїв заряду, що вiдповiдають за окремi смуги фотолюмiнесценцiї нанокристалiв CdS.
Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted ... more Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted great interest in tissue engineering and biofabrication. In these fields, new materials and approaches to prepare hydrogels without using toxic starting materials or materials that decompose into toxic compounds remain to be sought after. Here, we report the crosslinking of commercial, unfunctionalized hydrophilic poly(2-ethyl-2-oxazoline) using peroxide copolymers in their melt. The influence of temperature, peroxide copolymer concentration, and duration of the crosslinking process has been investigated. The method allows to create hydrogels from unfunctionalized polymers in their melt and to control the mechanical properties of the resulting materials. The design of hydrogels with a suitable mechanical performance is of crucial importance in many existing and potential applications of soft materials, including medical applications.
Hìmìâ, tehnologìâ rečovin ta ïh zastosuvannâ, Nov 1, 2021
Cross-linked polymer films based on polyvinyl alcohol and polyacrylamide have been prepared via r... more Cross-linked polymer films based on polyvinyl alcohol and polyacrylamide have been prepared via radical cross-linking initiated by peroxide containing reactive copolymers. The influence of temperature, nature and concentration of cross-linking agents onto gel-fraction value and properties of polymer films has been studied. Obtained cross-linked polymer films are characterized by improved physico-mechanical properties that depend on the content of peroxide containing copolymer and on the presence of additional cross-linking agent.
Polymeric microcapsules with paraffin core containing magnetite nanoparticles modified by oleic a... more Polymeric microcapsules with paraffin core containing magnetite nanoparticles modified by oleic acid and functional polymeric shell were synthesized using the technique of "extraction-coacervation" microencapsulation. The influence of process parameters onto colloidal chemical properties (size, dispersity index, surface porosity) of synthesized microcapsules was studied. It was shown that the use of heterofunctional copolymer as microcapsule shell allows the possibility of irreversible immobilization of α- amylase and provide its participation in the reaction of starch catalytic decomposition.
Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted ... more Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted great interest in tissue engineering and biofabrication. In these fields, new materials and approaches to prepare hydrogels without using toxic starting materials or materials that decompose into toxic compounds remain to be sought after. Here, we report the crosslinking of commercial, unfunctionalized hydrophilic poly(2-ethyl-2-oxazoline) using peroxide copolymers in their melt. The influence of temperature, peroxide copolymer concentration and duration of the crosslinking process has been investigated. The method allows to create hydrogels from unfunctionalized polymers in their melt and to control the mechanical properties of the resulting materials. The design of hydrogels with a suitable mechanical performance is of crucial importance in many existing and potential applications of soft materials, including medical applications.
Chemistry, Technology and Application of Substances, 2020
Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mi... more Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mineral nanoparticles of hydroxyapatite and silica have been obtained via radical cross- linking initiated by peroxide containing reactive copolymers. The influence of temperature and additional cross-linking agents on the peculiarities of curing process has been studied. The obtained results reveal that at high temperatures the dependence of film gel-fraction values on time has the extremal character. Obtained cross-linked nanocomposite films are characterized by improved physico-mechanical properties that depend on the nature of mineral nanoparticles, content of peroxide containing copolymer and on the presence of additional cross-linking agent.
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Papers by Viktor Tokarev