Alexander Tolstov
@ihvs.kiev.ua
Department of Polymer Composites
Institute of Macromolecular Chemistry NASU
RESEARCH, TEACHING, or OTHER INTERESTS
Materials Science, Polymers and Plastics, Materials Chemistry, Chemical Engineering
Scopus Publications
Scopus Publications
Ihor M. Tkachenko, Yuriy I. Kurioz, Ruslan M. Kravchuk, Alexander L. Tolstov, Anatoliy V. Glushchenko, Vassili G. Nazarenko, and Valery V. Shevchenko
Royal Society of Chemistry (RSC)
A novel azo-based polymer with high mechanical and thermal stability is obtained. The polymer exhibits stable birefringence changes, enabling the fabrication of diffraction gratings, showing its potential for various optical applications.
Tatyana Malysheva and Alexander Tolstov
IEEE
Dimethyldichlorosilane (DMCS) modified AM-300 nanosilica has a minor destabilization effect on C=Oδ- ···αHc)+ network and slightly reduces the tensile properties of PUU-I/PVC composites compared to composites filled with unmodified hydrophilic A-300 nanosilica. Introducing modified filler into PUU-2/PVC blend weakens intermolecular interactions at the interface. It sharply reduces the strength of filled polymer composites due to adsorption interactions of residual polar chlorine groups of DMCS modifier and proton donor NH groups of hard segments of the elastomer. At the same time, intracomponent C=Oδ-···αHc)+ interactions are practically unchanged and do not affect phase separation processes and functional characteristics of filled polymer nanocomposite films. It was found the optimal content of the filler for PUU-I/PVC blend reaches 3 wt.% for AM-300 or 1 wt. % for neat nanosilica. However, for PUU-2/PVC a filler content should not overcome 1 wt. %. So, the impact of interface interactions on tensile properties of nanostructured polymer blends depends mainly on the nature of the nanosilica modifier as well as the chemical structure of the poly(urethane-urea) matrix.
Olga Slisenko, Iryna Bei, Vira Budzinska, and Oleksandr Tolstov
IEEE
A novel dual network (DN) hydrogel composites based on partially neutralized polyacrylic acid (PAANa) and poly-N-(2-aminoethy1)-3-aminopropy1trimethoxysi1ane (PAPTMS) were synthesized by a combination of free radical polymerization of AANa in the presence of N,N’-methylenebis(acrylamide) cross-linker and hydrolysis of silica precursors and catalytically-induced condensation of the resulting hydroxyl groups of APTMS (from 5 to 20 wt.%) to form a network structure. The cross-linking of PAANa was verified by the absence of a C=C double bond by FTIR analysis. TGA of PAANa/PAPTMS hydrogels showed higher thermal stability compared to pure PAA hydrogel as well as the heat-resistance index (TiiRi) for PAANa/PAPTMS composites have greater values than additive ones. The hydrogels’ swelling capacity in distilled water is enhanced by 316% (from 16.81 to 70.06 g/g) at the incorporation of 10 wt% of PAPTMS. The mechanism of diffusion of hydrogels (except PAANa/PAPTMS = 80/20) has non-Fickian or anomalous character. The sorption curve of PAANa/PAPTMS = 80/20 sample has sigmoid character and was interpreted as a result of a combination of first-order kinetics and the overall autocatalytic process with its two rate constants.
Olga Zinchenko, Valentyna Ezhova, Olga Slisenko, and Alexander Tolstov
Informa UK Limited
Abstract Novel polymer hydrogel sensor materials were obtained and tested for pH and temperature responsive activity as well as sensitivity to ultralow copper ions content. Copper ion sensitive hybrid composites were prepared via photo-induced copolymerization of a mixture of acrylics and pre-synthesized methacrylate functionalized ZnO nanoparticles. Sensor activity of the composites is caused by extinguishing fluorescence of nano ZnO under impact of Cu2+ ions contaminant. It was observed a substantial increasing fluorescence intensity while Cu2+ ions content falls down from 10−1 to 10−6 mol/L. The acrylic matrix demonstrates pH and temperature responsive behavior as well.
Andrii I. Kovalchuk, Yaroslav L. Kobzar, Ihor M. Tkachenko, Alexander L. Tolstov, Oleg V. Shekera, and Valery V. Shevchenko
Elsevier BV
V. F. Matyushov, A. L. Tolstov, O. V. Gres, and P. S. Yaremov
Springer Science and Business Media LLC
Andrii I. Kovalchuk, Yaroslav L. Kobzar, Ihor M. Tkachenko, Alexander L. Tolstov, Oleg V. Shekera, and Valery V. Shevchenko
Elsevier BV
A. L. Tolstov, V. F. Matyushov, O. V. Zinchenko, V. D. Ezhova, and E. V. Lebedev
IEEE
Poly(urethane-urea) (PUU)/silver nanoparticles (AgNP) polymer composites were successfully produced by in situ synthesis of metal nanoparticles in the presence of polymer. UV-vis spectrometry of the composites demonstrates an appearance of broad plasmonic resonance absorption band of AgNP with concentration dependent intensity. Nanofiller playing a role of intercomponent interactions and phase structure regulation agent of the composites. It was clearly detected from appropriate changes in spectral position and integral intensities of polar C=O and N-H functions of rigid segments and ether groups of flexible polyether fragments of PUU matrix. Thermogravimetry analysis of the samples is evidenced of a shift of decomposition maximum to higher temperature region whereas thermal stability of neat PUU and PUU-based composites is similar. Specific sorption behavior of AgNP-containing composites could be explained by a presence of ionic by-products distributed uniformly in the PUU matrix when the reduction of Ag+ and a formation of AgNP occur. Analysis of tensile properties of the composites shown that PUU and all composites could be identified as thermoplastic elastomers strengthened by the nanofiller. Nevertheless the neat PUU is characterized by highest strength at break and elongation at break values.
V. F. Matyushov, A. L. Tolstov, L. V. Kobryna, P. S. Yaremov, V. G. Ilyin, and E. V. Lebedev
IEEE
Titanosilicate composite catalysts were synthesized from inorganic and elementorganic titania precursors and nanostructurized silicas as substrate by chemical liquid-phase deposition approach or from soluble titania and silica precursors by sol-gel process. The nature of TiO2 precursors and silica substrate affect by a level of intercomponent interactions (because of a formation of Si-O-Ti bonds was identified) and structurization of surface active layer of the catalysts. Phase structure and porosity of the composites could be regulated by changing a composition and synthesis conditions. Applying the different synthetic approaches the catalysts with meso- or microporous structures were prepared. From UV-DRS analysis it was found that TiO2 surface layer of the composites consists of as catalytically active tetracoordinated titanium sites (λabs ~ 200 nm) as well as low active pentacoordinated (λabs ~ 225 nm) and hexacoordinated titanium atoms (λabs ~ 245 nm). A relative ratio of the titanium sites could be controlled by selecting a nature of silica substrates. Efficiency of titanosilicate catalysts obtained was demonstrated in a reaction of liquid-phase oxidation of allyl alcohol by aqueous hydrogen peroxide. The yield of glycidol in the process reaches 25 %. Among other products the hydroxyl-and carboxyl-containing compounds are detected.
Ihor M. Tkachenko, Yaroslav L. Kobzar, Olha G. Purikova, Alexander L. Tolstov, Oleg V. Shekera, and Valery V. Shevchenko
Elsevier BV
A. L. Tolstov, O. V. Zinchenko, and V. F. Matyushov
Springer Science and Business Media LLC
A. L. Tolstov, I. M. Bey, and V. F. Matyushov
Springer Science and Business Media LLC
A. L. Tolstov
Springer Science and Business Media LLC
A. L. Tolstov, V. F. Matyushov, and O. N. Malanchuk
Springer Science and Business Media LLC
A. L. Tolstov and V. F. Matyushov
Springer Science and Business Media LLC
A. L. Tolstov
Springer Science and Business Media LLC
A. L. Tolstov and O. V. Gres
Springer Science and Business Media LLC
A. L. Tolstov and E. V. Lebedev
Springer Science and Business Media LLC
Alexander Tolstov, Daniel Gromadzki, Miloš Netopilík, and Ričardas Makuška
Walter de Gruyter GmbH
AbstractAnionic comb polyelectrolytes containing 2-acrylamido-2-methyl-Npropane sulfonate groups both in the mainchain and in the grafts were prepared by activators generated by electron transfer atom transfer radical polymerization (AGET ATRP). The synthetic route included AGET ATRP copolymerization of 2- acrylamido-2-methyl-N-propanesulfonic acid (AMPS) and 2-hydroxyethyl acrylate (HEA) followed by modification of HEA units in the copolymers by 2- bromoisobutyryl bromide yielding macroinitiators which served for “grafting from” AGET ATRP of AMPS. Composition of the final and intermediate products was determined by 1H-NMR spectroscopy, and molecular weight and polydispersity of the resulting polyelectrolytes were estimated by size exclusion chromatography (SEC). Anionic comb polyelectrolytes with relatively low density of the grafts (5 - 7 grafting sites per 100 monomeric units of the mainchain) and relatively short side chains (9 or 25 AMPS units) were synthesized and characterized.
I. Bei, A. Tolstov, and A. Ishchenko
Springer Netherlands
A. Tolstov, V. Matyushov, and D. Klimchuk
Springer Netherlands