10039 10040 10041 10042 10043
Publications on the project |
100 Non-precious Metal Oxygen Reduction Nanocomposite Electrocatalysts Based on Poly(phenylenediamines) with Cobalt |
Authors: | Ya. I. Kurys, O. O. Ustavytska, V. G. Koshechko, V. D. Pokhodenko | |
Summary: | The unpyrolyzed non-precious metal-polymer nanocomposite electrocatalysts for the oxygen reduction reaction (ORR) based on amino-substituted analogues of polyaniline (poly-o-phenylenediamine—PoPDA, poly-m-phenylenediamine—PmPDA), cobalt and carbon black were obtained. The activity of PmPDA- or PoPDA-based metal-polymeric composites for the ORR was higher than that for previously reported similar polyaniline-based composite. | |
Keywords: | Oxygen reduction reaction
Unpyrolyzed non-precious metal electrocatalysts
Poly(phenylenediamines)
Cobalt | |
Edition: | Electrocatalysis | | | ,
117-125,English |
100 The influence of carbon nanotubes functionalization on the structure and electrochemical properties of hybrid nanocomposites based on polyaniline and polypyrrole |
Authors: | N.V. Konoshchuk, S.O.Biskulova, О.Yu. Posudievsky, V.S.Dyadyun, V.H. Koshechko, V.D. Pokhodenko | |
Summary: | Hybrid nanocomposites based on polyaniline (PAn) and polypyrrole (PPy) and functionalized multiwalled carbon nanotubes (CNT) are prepared. It is shown that the method of CNT functionalization and the polymer nature substantially affect the structure and electrochemical properties of the nanocomposites. It is established that the conductivity and specific capacity of PPy/CNT nanocomposites are determined mainly by the content of CNT whereas in the case of PAn/CNT nanocomposites – the functionalization method is also improtant. It is shown that PAn/CNT(N-CNT) nanocomposites based on CNT functionalized using surface catalyst Aliquat 336 are characterized by the greatest specific capacity (366 and 294 F/g, respectively). | |
Keywords: | polyaniline, polypyrrole, carbon nanotubes, supercapacitors, method of functionalization | |
Edition: | Theoreticheskaya i eksperimentalnaya khimiya | | | 2014,
206–213,Russian |
100 Nanocomposite oxygen reduction electrocatalysts based polindol, cobalt and carbon black |
Authors: | Kurys Ya. I., Ustavytska O. O., Mazur D.O., Koshechko V. G., Pokhodenko V. D. | |
Summary: | | |
Keywords: | | |
Edition: | | | | 2014,
367–374,Russian |
100 High yield of graphene by dispersant-free liquid exfoliation of mechanochemically delaminated graphite |
Authors: | Oleg Yu. Posudievsky, Oleksandra A. Khazieieva, Vsevolod V. Cherepanov, Vyacheslav G. Koshechko, Vitaly D. Pokhodenko | |
Summary: | A tremendous work is being done to apply graphene to create novel advanced nanomaterials. The minimized number of few-layer graphene, the absence of different dispersants in the films produced from dispersions of graphene, the concentration of these dispersions are often a key to realizing the goal of achieving high functional performance. Here we show an efficient preparation of graphene by ultrasound disintegration in an organic solvent of the nanostructured graphite obtained by solvent-free mechanochemical delamination in the absence of chemically active compounds. The predominant part of single-sheet graphene nanoparticles in the obtained dispersions is experimentally confirmed. The proposed approach essentially improves the known liquid exfoliation method based on ultrasound disintegration of the bulk graphite, because the proposed preliminary mechanochemical treatment of the initial bulk graphite could provide more than 75 % yield of the single-sheet graphene nanoparticles in the dispersant-free high concentration dispersions (in different organic solvents, including ethanol). | |
Keywords: | Mechanochemical delamination of graphite
Graphene
Dispersant-free solvent exfoliation
Ethanol
Nanolayer
Nanofabrication | |
Edition: | Journal of Nanoparticle Research | | | 2013,
9 сторінок,English |
100 Mechanochemically prepared ternary hybrid cathode material for lithium batteries |
Authors: | Posudievsky O. Yu., Kozarenko O. A., Dyadyun V. S., Jorgensen S. W., Spearot J. A., Koshechko V. G., Pokhodenko V. D. | |
Summary: | Ternary host–guest nanocomposite based on vanadium oxide and two polymers with different types of conductivity (ionic and electronic) – polypyrrole (PPy) and polyethylene oxide (PEO) – is prepared by solventless mechanochemical synthesis. The nanocomposite can be reversibly cycled with a specific capacity of ∼200 mA h g−1 for at least one hundred cycles of full charge–discharge as the active component of the positive electrode of lithium batteries. Electrochemical performance of ternary PPy0.1PEO0.15V2O5 is compared with two-component analog PPy0.1V2O5. The presence of macromolecules of an ion-conducting polymer in the composition of the ternary nanocomposite PPy0.1PEO0.15V2O5 promotes interfacial transfer of lithium ions and also facilitates faster transport inside the particles of the nanocomposite. | |
Keywords: | Host–guest nanocomposite; Vanadium oxide; Conducting polymers; Mechanochemistry; Lithium ion transport; Lithium batteries | |
Edition: | Electrochimica Acta | | | 2013,
866–873,English |
100 Electrochemical performance of mechanochemically prepared polyaniline doped with lithium salt |
Authors: | Posudievsky O. Yu., Kozarenko O. A., Dyadyun V. S., Koshechko V. G., V. D. Pokhodenko | |
Summary: | Oxides and phosphates of transition metals are now predominant cathode materials of lithium-ion batteries. Organic redox active materials, conducting polymers in particular, could be a more environmentally friendly alternative. But their electrochemical characteristics were of insufficient level as to the charge capacity, rate capability and cyclability. Here, electrochemical performance of lithium salt doped polyaniline samples prepared by mechanochemical and chemical methods is comparatively analyzed as an active component of cathode masses of lithium batteries. It is shown that mechanochemically prepared polyaniline possesses specific capacity close to the theoretical limit as well as high rate capability and cyclability during prolonged charge–discharge. | |
Keywords: | Polyaniline; Mechanochemical preparation; Electrochemical performance; Cathode characteristics; Lithium ion battery | |
Edition: | Synthetic Metals | | | 2012,
2206–2211,English |
100 Effect of host–guest versus core–shell structure on electrochemical characteristics of vanadium oxide/polypyrrole nanocomposites |
Authors: | Posudievsky O. Yu., Kozarenko O. A., Dyadyun V. S., Jorgensen S. W., Spearot J. A., Koshechko V. G., Pokhodenko V. D | |
Summary: | Reduction in cost of lithium ion batteries is essential to the cost walk of electrified vehicles. Electrode microstructure can significantly affect capacity and thus cost. The effect of structure – host–guest versus core–shell – on electrochemical characteristics of transition metal oxide/conducting polymer nanocomposites as the active component of the positive electrode of lithium batteries was studied using two types of polypyrrole based hybrids one prepared with vanadium oxide xerogel and the other with crystalline V2O5. It was shown that the host–guest structure can provide substantially higher stability under charge–discharge cycling, faster transport of lithium ions and allows redox processes at higher potentials. | |
Keywords: | Host–guest; Core–shell; Hybrid nanocomposite; Cyclability; Cathode | |
Edition: | Electrochimica Acta | | | 2011,
442–448,English |
100 Characteristics of mechanochemically prepared host-guest hybrid nanocomposites of vanadium oxide and conducting polymers |
Authors: | Posudievsky O. Yu., Kozarenko O. A., Dyadyun V. S., Jorgensen S. W., Spearot J. A., Koshechko V. G., Pokhodenko V.D. | |
Summary: | A set of two-component guest–host nanocomposites composed of conducting polymers and vanadium oxide are prepared via a single-step, solvent-free synthesis. The composition, structure, physical and electrochemical properties of these materials are studied. The nanocomposites have a guest–host structure, with the conducting polymer located in the interlayer space of the inorganic nanoparticles. The nanocomposites are capable of reversible cycling as the positive electrode in a lithium ion cell, and retain their capacity over one hundred full charge–discharge cycles. After cycling at a current of ∼0.2 A g−1, their capacity is restored when cycling at lower current, demonstrating the stability of their structure. | |
Keywords: | Host–guest; Nanocomposite; Cathode; Lithium ion battery; Mechanical milling; Conducting polymer | |
Edition: | Journal of Power Sources | | | 2011,
3331–3341,English |
100 Comparative analysis of sensor responses of thin conducting polymer films to organic solvent vapors |
Authors: | Posudievsky O. Yu., Konoschuk N. V., Kukla A. L., Pavluchenko A. S., Shirshov Yu. M., Pokhodenko V. D. | |
Summary: | A comparative analysis of responses of thin films of various conducting polymers (polyaniline, polypyrrole and poly-3-methylthiophene) to the vapors of polar as well as low- and nonpolar organic solvents was performed. Conductivity measurements, infra-red and electron paramagnetic resonance spectroscopy were used to characterize responses of the polymer films doped with different dopants. Main physical and chemical factors which define the magnitude of the response to the studied analytes were determined. It was shown that the differences in response of conducting polymer films are conditioned by the influence of chemical structure of the polymer and its dopant, and also by different nature of their doping. | |
Keywords: | Conducting polymer films; Polyaniline; Polypyrrole; Poly-3-methyltiophene; Sensor response; Organic solvent | |
Edition: | Sensors Actuators B | | | 2011,
351–359,English |
100 Effect of monomer/oxidant mole ratio on polymerization mechanism, conductivity and spectral characteristics of mechanochemically prepared polypyrrole |
Authors: | Posudievsky O. Yu., Kozarenko O. A. | |
Summary: | The effect of the composition of the initial reaction mixture – pyrrole/oxidant mole ratio – on the mechanism of mechanochemical polymerization of pyrrole was studied. Experimental evidence in favor of the chain mechanism for mechanochemical formation of the highly conducting PPy at high monomer/oxidant mole ratio was first obtained. Interrelation between polymerization mechanism and structure, conductivity and spectral characteristics of the prepared polypyrrole samples was considered. | |
Keywords: | | |
Edition: | Polymer Chemistry | | | 2011,
216–220,English |
100 Structure–property relationship in mechanochemically prepared polyaniline |
Authors: | Posudievsky O. Yu., Goncharuk O. A., Barillé R., Pokhodenko V. D. | |
Summary: | The comparative analysis of the physicochemical properties of polyaniline prepared in the conditions of solventless mechanochemical treatment in the ball mill (PAni|mch) and polyaniline synthesized by the usual oxidative polymerization in the solvent (PAni|c) is carried out. Conductivity of PAni|mch substantially exceeds that of PAni|c. As molecular weights of PAni|mch and PAni|c are comparable, the observed difference could be connected with the influence of mechanical stress which affects the polymer during its mechanochemical preparation. The increased conductivity of polyaniline obtained by post-synthesis mechanochemical treatment of PAni|c (PAni|mt) confirms such explanation. It could be concluded from the results of the structural investigations as well as of spectral and electrochemical studies that the shear stress which exerts influence on the polymer during mechanochemical synthesis or mechanochemical treatment leads to the increase of the interchain π–π interaction and, consequently, to the efficient improvement of conductivity. | |
Keywords: | Polyaniline; Mechanochemical preparation; Conductivity; Structure–property relationship | |
Edition: | Synthetic Metals | | | 2010,
462–467,English |
100 Mechanochemical preparation of conducting polymers and oligomers |
Authors: | Posudievsky O. Yu., Goncharuk O. A., Pokhodenko V. D. | |
Summary: | Three types of conducting polymers – polypyrrole (PPy), polythiophene (PTh), and polyparaphenylene (PPP), – are prepared by environmentally friendly and efficient solvent-free mechanochemical method. The experimental data obtained in the work argue for a high molecular weight for PPy, whereas PTh and PPP are represented by different oligomers. Measurements of conductivity confirm formation of the doped state of PPy, weakly doped state of PTh and non-doped state of PPP. Interrelation between the doping state and degree of polymerization is discussed. | |
Keywords: | Mechanochemical preparation; Polypyrrole; Polythiophene; Polyparaphenylene; Spectral properties; Conductivity | |
Edition: | Synthetic Metals | | | 2010,
47–51,English |
The events in the framework of the project |
|
100 6. Nanochemistry Purpose:Development of organic electronics nanomaterials based on conducting polymers by structural and functional design of new hybrid organic-inorganic nanocomposites as effective functional materials for chemical power sources, supercapacitors, light-emitting diodes, sensors and sensor arrays etc. Expected results:Release of new product: material Stage 1:Development of methods for preparing hybrid organic-inorganic nanocomposites as electroluminescent materials of light-emitting diodes, cathode materials of lithium batteries, electrodes of supercapacitors, nanoelectrocatalysts of oxygen reduction, elements of sensor arrays. Stage 2:Study of the functional properties and composition optimization of hybrid nanocomposite materials as electroluminescent materials of light-emitting diodes, cathode materials of lithium batteries, electrodes of supercapacitors, nanoelectrocatalysts of oxygen reduction, elements of sensor arrays. Stage 3:Development and testing of models of lithium batteries and supercapacitors with hybrid nanocomposites based electrodes. Stage 4:Development and testing of sensor arrays with hybrid nanocomposites based on conducting polymers for determination of polar and low-polar organic solvents in the gas phase. Stage 5:Development and material testing for hybrid light-emitting diodes and photovoltaic systems.
|