Труды сотрудников ИВМ СО РАН

/ I. I. Ryzhkov // International Journal of Heat and Mass Transfer. - 2013. - Vol. 66. - pp. 461-471, DOI 10.1016/j.ijheatmasstransfer.2013.07.044 . - ISSN 0017-9310
Аннотация: A simple and efficient method for solving the extended Graetz problem with specified heat flux in a circular pipe for a multicomponent fluid with Soret and Dufour effects is proposed. With a help of linear transformation of temperature and concentrations, the mass transfer equation and boundary conditions for each component are reduced to the form, which is completely identical to the thermal Graetz problem. The case when only the Soret effect is relevant is studied separately. It is shown that the above-described reduction fails when thermal and solutal Peclet numbers are equal. An alternative method of solution is proposed in this case. Examples of heat and mass transfer in a circular pipe for low Peclet numbers in a model fluid and for high Peclet numbers in the water-alumina nanofluid are considered. The proposed method can be extended to a parallel plate channel as well as annular region between cylindrical pipes with specified heat flux. However, the method cannot be applied to problems, where the temperature is specified on the impermeable pipe wall. В© 2013 Elsevier Ltd. All rights reserved.

Scopus


Доп.точки доступа:
Ryzhkov, I.I.; Рыжков, Илья Игоревич

[Text] / I. I. Ryzhkov, A. V. Minakov // Int. J. Heat Mass Transf. - 2014. - Vol. 77. - P956-969, DOI 10.1016/j.ijheatmasstransfer.2014.05.045. - Cited References: 44. - This work is supported the Krasnoyarsk Regional Foundation of Scientific and Technical Activity (Grant No. 02/13) and the Russian President Grant No. MK-6296.2013.8. . - ISSN 0017-9310. - ISSN 1879-2189РУБ Thermodynamics + Engineering, Mechanical + Mechanics

Аннотация: Laminar convective heat transfer of water-alumina nanofluid in a circular tube with uniform heat flux is investigated numerically on the basis of two-component model, which takes into account nanoparticle transport by diffusion and thermophoresis. A new expression for thermophoretic mobility is suggested on the basis of existing experimental results and theoretical concepts. It is shown that thermophoresis leads to a significant reduction of nanoparticle volume fraction in the boundary layer near the wall. The corresponding viscosity reduction causes the velocity increase near the wall and flattening of velocity profile near the tube axis to keep the mass flow rate constant. The decrease of wall shear stress leads to the decrease of the required pressure drop. The calculations for two-component model provide higher values of the local and average heat transfer coefficients in comparison with the one-component model. The difference does not exceed 10% and decreases with increasing the thermal Peclet number. The calculations for one-component model show the independence of local and average Nusselt numbers on the nanoparticle volume fraction. The results for two-component model predict the increase of Nusselt number when the thermophoretic effect becomes stronger. The effectiveness of water-alumina nanofluid is analyzed by plotting the average heat transfer coefficient against the required pumping power. It is shown that the nanofluid shows better performance than the base fluid in the range of low pumping power and, correspondingly, low inlet velocity. (C) 2014 Elsevier Ltd. All rights reserved.

WOS

Держатели документа:
[Ryzhkov, Ilya I.] SB RAS, Inst Computat Modelling, Krasnoyarsk 660036, Russia
[Minakov, Andrey V.] Siberian Fed Univ, Inst Engn Phys & Radio Elect, Krasnoyarsk 660041, Russia
ИВМ СО РАН

Доп.точки доступа:
Ryzhkov, I.I.; Рыжков, Илья Игоревич; Minakov, A.V.; Минаков, Андрей Викторович; Krasnoyarsk Regional Foundation of Scientific and Technical Activity [02/13]; Russian President Grant [MK-6296.2013.8]

/ I. V. Uskov, G. G. Krushenko // Litejnoe Proizvodstvo. - 1994. - Is. 3. - P9-10 . - ISSN 0024-449X
Аннотация: A study is made of a standard pickup preventing coating made from white synthetic aluminium oxide powder and polyvinylbutyral varnish and used for moulds and cores. With 1.5-1.6% of ultradispersed powder in place of white synthetic aluminum oxide, a new coating has been developed having a sedimentation stability of 89 against 70 for the standard coating. Casting surfaces of steel 35L show the roughness of the new coating of 185-190 be absent pickup throughout the casted sample. Members of steels 110G13L and 45L were also put through tests.

Scopus

Держатели документа:
Vychislitel'nyj Tsentr SO RAN, Krasnoyarsk, Russian Federation
ИВМ СО РАН

Доп.точки доступа:
Uskov, I.V.; Krushenko, G.G.; Крушенко, Генрих Гаврилович

[Text] / S. V. Kozlova, I. I. Ryzhkov // Eur. Phys. J. E. - 2014. - Vol. 37, Is. 9. - Ст. 87, DOI 10.1140/epje/i2014-14087-0. - Cited References: 44. - The authors are grateful to Dr. A. V. Minakov for assistance in ANSYS Fluent numerical calculations. This work is supported the Krasnoyarsk Regional Foundation of Scientific and Technical Activity (Grant 02/13). . - ISSN 1292-8941. - ISSN 1292-895XРУБ Chemistry, Physical + Materials Science, Multidisciplinary + Physics, Applied + Polymer Science

Аннотация: In this paper, laminar convective heat transfer of water-alumina nanofluid in a circular tube with uniform heat flux at the tube wall is investigated. The investigation is performed numerically on the basis of two-component model, which takes into account nanoparticle transport by diffusion and thermophoresis. Two thermal regimes at the tube wall, heating and cooling, are considered and the influence of nanoparticle migration on the heat transfer is analyzed comparatively. The intensity of thermophoresis is characterized by a new empirical model for thermophoretic mobility. It is shown that the nanoparticle volume fraction decreases (increases) in the boundary layer near the wall under heating (cooling) due to thermophoresis. The corresponding variations of nanofluid properties and flow characteristics are presented and discussed. The intensity of heat transfer for the model with thermophoresis in comparison to the model without thermophoresis is studied by plotting the dependence of the heat transfer coefficient on the Peclet number. The effectiveness of water-alumina nanofluid is analyzed by plotting the average heat transfer coefficient against the required pumping power. The analysis of the results reveals that the water-alumina nanofluid shows better performance in the heating regime than in the cooling regime due to thermophoretic effect.

WOS

Держатели документа:
[Kozlova, Sofya V.
Ryzhkov, Ilya I.] Inst Computat Modelling SB RAS, Krasnoyarsk 660036, Russia
ИВМ СО РАН

Доп.точки доступа:
Kozlova, S.V.; Ryzhkov, I.I.; Рыжков, Илья Игоревич; Krasnoyarsk Regional Foundation of Scientific and Technical Activity [02/13]

[Text] / M. M. Simunin [et al.] // Tech. Phys. Lett. - 2015. - Vol. 41, Is. 11. - P1047-1050, DOI 10.1134/S1063785015110103. - Cited References:20. - This work was supported financially by the Russian Science Foundation, project no. 15-19-10017. . - ISSN 1063-7850. - ISSN 1090-6533РУБ Physics, Applied

Аннотация: A structure based on porous anodic alumina with through pores is synthesized. This structure may be of some interest in terms of fabricating electrically switchable membranes. Conducting tubulenes connected to a common input electrode are located in the pores of the structure. It is hypothesized that enhancement of the electric field nonuniformity associated with the indicated structure morphology should help raise the degree of ionic selectivity of the membrane and broaden the range of permissible concentrations of ions in the processed solution. An suggestion regarding the structure of synthesized tubulenes in the context of the problem of suppressing the physical sorption of ions on the pore surface and raising the hydrogen and oxygen reduction potentials relative to those of state-of-the-art field-switchable membranes is also made.

WOS,
Scopus

Держатели документа:
Natl Res Univ Elect Technol MIET, Moscow 124498, Russia.
Siberian Fed Univ, Krasnoyarsk 660041, Russia.
Russian Acad Sci, Siberian Branch, Krasnoyarsk Sci Ctr, Krasnoyarsk 660036, Russia.
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia.
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Simunin, M. M.; Khartov, S. V.; Shiverskii, A. V.; Zyryanov, V. Ya.; Fadeev, Y. V.; Фадеев Ю.В.; Voronin, A. S.; Russian Science Foundation [15-19-10017]

/ D. V. Lebedev [et al.] // Pet. Chem. - 2017. - Vol. 57, Is. 4. - P306-317, DOI 10.1134/S096554411704003X. - Cited References:52. - This work was supported by the Russian Science Foundation, grant no. 15-19-10017. Instrumental analysis of the materials was performed in the Shared Equipment Center at the Krasnoyarsk Scientific Center, Siberian Branch of the Russian Academy Sciences. . - ISSN 0965-5441. - ISSN 1555-6239РУБ Chemistry, Organic + Chemistry, Physical + Energy & Fuels + Engineering,

Аннотация: A novel type of ion-selective membranes based on Nafen(TM) alumina nanofibers coated with carbon is proposed. The membranes are produced by filtration of a Nafen nanofiber suspension through a porous support followed by drying and sintering. A thin carbon layer (up to 2 nm) is deposited on the nanofibers by chemical vapor deposition (CVD). Its formation is confirmed by the results of Raman spectroscopy and visually observed in TEM images. According to low temperature nitrogen adsorption experiments, the formation of carbon layer leads to decreasing pore size (the maximum of pore size distribution shifts from 28 to 16 nm) and the corresponding decrease of porosity (from 75 to 62%) and specific surface area (from 146 to 107 m(2)g(-1)). The measurement of membrane potential in an electrochemical cell has shown that the deposition of carbon on the membrane results in high ionic selectivity. In an aqueous KCl solution, the membranes display high anion selectivity with anion and cation transference numbers of 0.94 and 0.06, respectively. The fixed-charge density of membrane has been determined by fitting the experimental data using the Teorell-Meyer-Sievers model. It has been found that the membrane fixed-charge density increases with increasing electrolyte concentration. Possible applications of the membranes produced include nanofiltration, ultrafiltration, and separation of charged species in mixtures. The formation of a conductive carbon layer on the pore surface can be employed for fabricating membranes with switchable ion-transport selectivity.

WOS,
Смотреть статью,
Scopus

Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk, Russia.
Russian Acad Sci, Siberian Branch, Mol Elect Dept, Krasnoyarsk Sci Ctr, Krasnoyarsk, Russia.
Natl Res Univ Elect Technology MIET, Moscow, Russia.
Russian Acad Sci, Siberian Branch, Inst Chem & Chem Technol, Krasnoyarsk, Russia.

Доп.точки доступа:
Lebedev, D.V.; Лебедев Д.В.; Shiverskiy, A. V.; Simunin, M. M.; Solodovnichenko, V.S.; Солодовниченко В.С.; Parfenov, V. A.; Bykanova, V. V.; Khartov, S. V.; Ryzhkov, I.I.; Рыжков, Илья Игоревич; Russian Science Foundation [15-19-10017]

[Текст] : статья / Д. В. Лебедев [и др.] // Мембраны и мембранные технологии. - 2017. - Т. 7, № 2. - С. 86-98, DOI 10.1134/S2218117217020031 . - ISSN 2218-1172
Аннотация: Предложен новый тип керамических мембран с ионной селективностью на основе нановолокон оксида алюминия (NafenTM), покрытых слоем углерода. Синтез мембран осуществляется методом вакуумной фильтрации коллоидного раствора волокон Nafen с последующим термическим отжигом и нанесением углеродного слоя методом химического осаждения из газовой фазы (chemical vapor deposition, CVD). Данные просвечивающей электронной микроскопии и спектроскопии комбинационного рассеяния подтверждают формирование углеродного слоя толщиной до 2 нм на нановолокнах. По данным низкотемпературной адсорбции азота, это приводит к уменьшению размера пор (максимум функции распределения смещается от 28 к 16 нм) и соответственному снижению пористости (с 75 до 62%) и удельной поверхности мембраны (с 146 до 107 м2 г–1). С помощью потенциометрического метода установлено, что нанесение углеродного слоя на мембраны из волокон Nafen придает им выраженные ионоселективные свойства. Измерения в водном растворе KCl показали, что полученные мембраны являются анион-селективными с числами переноса 0.94 для аниона и 0.06 для катиона. Определена плотность фиксированного заряда мембран путем аппроксимации экспериментальных данных моделью Теорелла–Мейера–Сиверса. Показано, что плотность заряда возрастает с увеличением концентрации электролита. Полученные мембраны могут быть применены в области нано- и ультрафильтрации, а также для разделения заряженных компонентов смесей. Нанесение проводящего углеродного слоя на поверхность пор является перспективным для создания мембран с управляемой ионной селективностью.
A novel type of ion-selective membranes based on NafenTM alumina nanofibers covered with carbon is proposed. The membranes are produced by filtration of Nafen nanofiber suspension through a porous support followed by drying and sintering. A thin carbon layer (up to 2 nm) is deposited on the nanofibers with the help of chemical vapor deposition (CVD). Its formation is confirmed by the results of Raman spectroscopy and visually observed in TEM images. According to low temperature nitrogen adsorption experiments, the formation of carbon layer leads to decreasing pore size (the maximum of pore size distribution shifts from 28 to 16 nm) and the corresponding decrease of porosity (from 75 to 62%) and specific surface area (from 146 to 107 m2 g–1). The measurement of membrane potential in an electrochemical cell shows that the deposition of carbon on the membrane results in high ionic selectivity. In an aqueous KCl solution, the membranes display high anion–selectivity with transference numbers 0.94 for anion and 0.06 for cation. The fixed charge density of membrane is determined by fitting the experimental data with the help of Teorell–Meyer–Sievers model. It is found that the density of fixed membrane charge increases with increasing the electrolyte concentration. The potential applications of produced membranes include nano- and ultrafiltration as well as separation of charged species in mixtures. The formation of conductive carbon layer on the pore surface can be employed for producing membranes with switchable ion-transport selectivity. Keywords: alumina nanofiber, membrane, chemical vapor deposition, carbon, membrane potential measurement, ionic permselectivity, Teorell–Meyer–Sievers model

РИНЦ

Держатели документа:
Институт вычислительного моделирования СО РАН, Академгородок 50-44, Красноярск, Россия
Институт химии и химической технологии СО РАН, Академгородок 50-24, Красноярск, Россия
Красноярский научный центр СО РАН, Академгородок 50, Красноярск, Россия
Национальный исследовательский университет “МИЭТ”, Площадь Шокина, 1, Зеленоград, Москва, Россия

Доп.точки доступа:
Лебедев, Д.В.; Шиверский, А.В.; Симунин, М.М.; Солодовниченко, В.С.; Парфенов, В.А.; Быканова, В.В.; Хартов, С.В.; Рыжков, И.И.

/ I. I. Ryzhkov [et al.] // Chemical Engineering Transactions : Italian Association of Chemical Engineering - AIDIC, 2017. - Vol. 60. - P253-258, DOI 10.3303/CET1760043 . -
Аннотация: A novel type of ion-selective membranes, which combine the advantages of ceramic nanofibrous media with good electrical conductivity, is proposed. The membranes are produced from Nafen alumina nanofibers (diameter around 10 nm) by filtration of nanofiber suspension through a porous support followed by drying and sintering. Electrical conductivity is achieved by depositing a thin carbon layer on the nanofibers by CVD. Raman spectroscopy and TEM are used to confirm the carbon structure formation. The average pore size determined by low temperature nitrogen adsorption experiments lies in the range 15-30 nm. Measurements of membrane potential show that the carbon coated membranes acquire high ionic selectivity (transference numbers 0.94 for anion and 0.06 for cation in aqueous KCl). The fixed membrane charge is determined by fitting the experimental data to Teorell-Meyer-Sievers and Space-charge models. © 2017, AIDIC Servizi S.r.l.

Scopus,
Смотреть статью

Держатели документа:
Institute of Computational Modelling SB RAS, Akademgorodok 50-44, Krasnoyarsk, Russian Federation
Molecular Electronics Department KSC SB RAS, Akademgorodok 50-44, Krasnoyarsk, Russian Federation
National Research University of Electronic Technology, MIET, Shokin square 1, Zelenograd, Moscow, Russian Federation
Institute of Chemistry and Chemical Technology SB RAS, Akademgorodok 50-24, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Ryzhkov, I. I.; Lebedev, D. V.; Solodovnichenko, V. S.; Shiverskiy, A. V.; Simunin, M. M.; Parfenov, V. A.

/ V. S. Solodovnichenko [et al.] // Adv. Eng. Mater. - 2017. - Vol. 19, Is. 11. - Ст. 1700244, DOI 10.1002/adem.201700244. - Cited References:60. - This work is supported by the Russian Science Foundation, Project 15-19-10017. The physicochemical analysis of materials was carried out on equipment of Krasnoyarsk Scientific Center of Shared Facilities SB RAS. . - ISSN 1438-1656. - ISSN 1527-2648РУБ Materials Science, Multidisciplinary

Аннотация: The authors propose a novel type of ion-selective membranes, which combine the advantages of ceramic nanofibrous media with good electrical conductivity. The membranes are produced from Nafen alumina nanofibers (diameter around 10nm) by filtration of nanofiber suspension through a porous support followed by drying and sintering. Electrical conductivity is achieved by depositing a thin carbon layer on the nanofibers by chemical vapor deposition (CVD). Raman and FTIR spectroscopy, X-ray fluorescence analysis, and TEM are used to confirm the carbon structure formation. The deposition of carbon leads to decreasing porosity (from 75 to 62%) and specific surface area (from 146 to 107m(2) g(-1)) of membranes, while the pore size distribution maximum shifts from 28 to 16nm. Measurements of membrane potential in an electrochemical cell show that the carbon coated membranes acquire high ionic selectivity (transference numbers 0.94 for anion and 0.06 for cation in aqueous KCl). Fitting the membrane potential data by the Teorell-Meyer-Sievers model shows that the fixed membrane charge increases proportionally with increasing electrolyte concentration. The carbon coated membranes are ideally polarizable for applied voltages from -0.5 to +0.8V. The potential applications of produced membranes include nano- and ultrafiltration, separation of charged species, and switchable ion-transport selectivity.

WOS,
Смотреть статью

Держатели документа:
Inst Computat Modeling SB RAS, Akademgorodok 50-44, Krasnoyarsk, Russia.
Fed Res Ctr KSC SB RAS, Akademgorodok 50, Krasnoyarsk, Russia.
Natl Res Univ Elect Technol MIET, Shokin Sq 1, Moscow, Russia.
Inst Chem & Chem Technol SB RAS, Akademgorodok 50-24, Krasnoyarsk, Russia.

Доп.точки доступа:
Solodovnichenko, Vera S.; Lebedev, Denis V.; Bykanova, Victoria V.; Shiverskiy, Alexey V.; Simunin, Mikhail M.; Parfenov, Vladimir A.; Ryzhkov, Ilya I.; Russian Science Foundation [15-19-10017]

/ D. V. Lebedev [et al.] // Pet. Chem. - 2018. - Vol. 58, Is. 6. - P474-481, DOI 10.1134/S0965544118060075. - Cited References:32. - This work was supported by the Russian Science Foundation, project no. 15-19-10017. The instrumental analysis of the materials was conducted at the Center for collective use of the Federal Research Center Krasnoyarsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences. . - ISSN 0965-5441. - ISSN 1555-6239РУБ Chemistry, Organic + Chemistry, Physical + Energy & Fuels + Engineering,

Аннотация: The effect of an external electric field on the ionic conductivity and selective properties of ceramic membranes based on alumina nanofibers coated with a conductive carbon layer has been studied. It has been shown that the membranes are ideally polarizable in the polarizing voltage range of -500 to +500 mV and, therefore, can be used for implementing switchable ionic selectivity. Experiments have revealed that the membrane resistance decreases with a change in the applied potential from 0 to +/- 500 mV. It has been shown that the membrane selectivity can be switched from anion to cation by varying the external potential. The surface charge density of the membranes has been determined in terms of the Teorell-Meyer-Sievers model according to the experimental measurements of the membrane potential.

WOS,
Смотреть статью,
Scopus

Держатели документа:
Russian Acad Sci, Siberian Branch, Krasnoyarsk Sci Ctr, Inst Computat Modeling, Krasnoyarsk 660036, Russia.
St Petersburg State Univ, Inst Chem, St Petersburg 198504, Russia.
Siberian Fed Univ, Krasnoyarsk 660041, Russia.

Доп.точки доступа:
Lebedev, D. V.; Solodovnichenko, V. S.; Simunin, M. M.; Ryzhkov, I. I.; Russian Science Foundation [15-19-10017]

[Текст] : статья / Д. В. Лебедев [и др.] // Мембраны и мембранные технологии. - 2018. - Т. 8, № 3. - С. 157-165, DOI 10.1134/S2218117218030070 . - ISSN 2218-1172
   Перевод заглавия: The Influence of Electric Field on The Ion Transport on Nanoporous Membranes with Conductive Surface

УДК

66.081.6

Аннотация: В работе исследуется влияние внешнего электрического поля на ионную проводимость и селективные свойства керамических мембран на основе нановолокон оксида алюминия, покрытых проводящим слоем углерода. Показано, что мембраны являются идеально поляризуемыми в области поляризующих напряжений от –500 до +500 мВ, что позволяет использовать их для реализации управляемой ионной селективности. Экспериментально установлено, что сопротивление мембраны уменьшается при изменении приложенного к ней потенциала от 0 до ±500 мВ. Продемонстрирована возможность изменения селективности мембраны от аниона к катиону в зависимости от внешнего потенциала. На основе экспериментальных измерений мембранного потенциала определена поверхностная плотность заряда мембран с помощью модели Теорелла–Мейера–Сиверса.
In this work, we investigate the influence of external electric field on the ionic conductivity and selectivity of ceramic membranes based on alumina nanofibers covered with conductive carbon layer. It is shown that the membranes are ideally polarizable in the range of voltages from –500 mV to +500 mV, which makes them suitable candidates for realizing switchable ionic selectivity. It is found experimentally that the membrane resistance decreases with increasing the potential applied to the membrane from 0 to ±500 mV. The possibility of changing the membrane selectivity from anion to cation depending on the applied potential is demonstrated. The membrane surface charge density is determined from experimental measurements of membrane potential with the help of Teorell-Meyer-Sievers model. Keywords: ceramic membranes, nanopore, conductive surface, ionic selectivity, ionic conductivity, switchable ion transport

РИНЦ

Держатели документа:
Красноярский научный центр СО РАН
Санкт-Петербургский государственный университет, Институт химии, Университетский проспект, 26, Санкт-Петербург, Петергоф, 198504 Россия
Сибирский федеральный университет

Доп.точки доступа:
Лебедев, Д.В.; Lebedev D.V.; Солодовниченко, В.С.; Solodovnichenko V.S.; Симунин, М.М.; Simunin M.M.; Рыжков, И.И.; Ryzhkov I.I.

/ V. S. Solodovnichenko [et al.] // Thermochim. Acta. - 2019. - Vol. 675. - P164-171, DOI 10.1016/j.tca.2019.02.012. - Cited References:50. - The work is supported by the Russian Foundation for Basic Research Grant no. 18-29-19078. The physicochemical analysis of materials was carried out on equipment of Krasnoyarsk Scientific Center of Shared Facilities SB RAS. . - ISSN 0040-6031. - ISSN 1872-762XРУБ Thermodynamics + Chemistry, Analytical + Chemistry, Physical

Аннотация: Catalyst-free chemical vapor deposition is used to form thin (1-2 nm) carbon layers on the surface of alumina nanofibers resulting in carbon-alumina nanocomposites. Thermal analysis, X-ray fluorescent microanalysis, Raman spectroscopy, and electrical resistance measurements of these composites show that increasing of synthesis time not only increases the amount of carbon on alumina surface, but also the ordering and density of the carbon layers. Nitrogen adsorption data reveal the decrease of total pore volume with increasing the synthesis time. The obtained composite material could be employed for the preparation of ion-selective membranes with switchable ion transport, electroconductive ceramics, and electrochemical sensors.

WOS,
Смотреть статью,
Scopus,
РИНЦ

Держатели документа:
Fed Res Ctr KSC SB RAS, Inst Computat Modelling SB RAS, Akademgorodok 50-44, Krasnoyarsk, Russia.
Siberian Fed Univ, Svobodny 79, Krasnoyarsk 660041, Russia.
St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia.
Fed Res Ctr KSC SB RAS, Akademgorodok 50, Krasnoyarsk, Russia.
Natl Res Univ Elect Technol, MIST, Shokin Sq 1, Moscow, Russia.
Fed Res Ctr KSC SB RAS, Inst Chem & Chem Technol, Akademgorodok 50-24, Krasnoyarsk, Russia.

Доп.точки доступа:
Solodovnichenko, Vera S.; Simunin, Mikhail M.; Lebedev, Denis, V; Voronin, Anton S.; Emelianov, Aleksei, V; Mikhlin, Yuri L.; Parfenov, Vladimir A.; Ryzhkov, Ilya I.; Russian Foundation for Basic Research Grant [18-29-19078]

/ A. V. Minakov, M. M. Simunin, I. I. Ryzhkov // Int. J. Heat Mass Transf. - 2019. - Vol. 145. - Ст. 118764, DOI 10.1016/j.ijheatmasstransfer.2019.118764 . - ISSN 0017-9310
Аннотация: Chemical vapour deposition (CVD) is widely used for preparation of pyrolytic carbons from various precursors. The prediction of deposition kinetics requires deep understanding of all transport phenomena involved. In this work, we perform the computational modelling of ethanol pyrolysis in a commercial CVD reactor (a tube furnace). The reactor is employed for growing carbon layers on alumina substrates. The inlet gas flow is produced by evaporating azeotrope ethanol/water mixture and mixing it with inert gas (argon). The modelling is performed in 3D and 2D statements using Marinov mechanism with 57 species participating in 383 reactions. The heat and species transport is taken into account with temperature dependent physical properties. It is shown that the inlet gas velocity in the 2D statement should be corrected for a meaningful comparison with the 3D case. A good agreement is found between species mole fractions at the substrate position for 3D and 2D statements at low volume flow rates, while at high flow rates some deviations are observed. The temperature at the substrate position is found to be lower than at the reactor wall due to inflow of a colder gas. The main pyrolysis products at moderate temperatures (around 900 °C) are water, ethylene, hydrogen, carbon monoxide, and methane. With increasing temperature, the mole fractions of hydrogen, acetylene, and carbon monoxide increase, while those of water and methane become smaller. With increasing ethanol/water volume flow rate, the mole fractions of ethanol and pyrolysis products saturate at some constant values due to incomplete thermal decomposition of ethanol in the reactor volume. The rise of argon flow rate leads to the decrease of pyrolysis products mole fractions due to decrease of residence time. The obtained results can be employed for simulating and analyzing pyrolysis processes in realistic CVD reactors with complex geometry as well as for the development of coupled gas phase and surface reaction model of carbon layer deposition on nanoporous substrates. © 2019 Elsevier Ltd

Scopus,
Смотреть статью

Держатели документа:
Siberian Federal University, Svobodny 79, Krasnoyarsk, 660041, Russian Federation
Institute of Computational Modelling SB RAS, Akademgorodok 50–44, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Minakov, A. V.; Simunin, M. M.; Ryzhkov, I. I.

/ N. O. Ronzhin, E. D. Posokhina, E. V. Mikhlina [et al.] // Dokl. Chem. - 2019. - Vol. 489, Is. 1. - P267-271, DOI 10.1134/S001250081911003X . - ISSN 0012-5008
Аннотация: Abstract: A composite of alumina nanofibers (ANF) and modified detonation nanodiamonds (MDND) was produced by mixing aqueous suspensions of the components in a weight ratio of 5 : 1 with subsequent incubation of the mixture for 15 min at 32°C. It was assumed that the formation of the composite is ensured by the difference of the zeta potentials of the components, which is negative for MDND and positive for ANF. Vacuum filtration of the mixture through a fluoroplastic filter (pore diameter 0.6 ?m) formed disks 40 mm in diameter, which were then heat-treated at 300°C to impart structural stability to the composite. Scanning electron microscopy detected that the obtained composite has a network structure, in which MDND particles are distributed over the surface of ANF. It was determined that the MDND particles incorporated in the composite catalyze the phenol–4-aminoantipyrine–H2O2 oxidative azo coupling reaction to form a colored product (quinoneimine). The applicability of the composite to repeated phenol detection in aqueous samples was demonstrated. © 2019, Pleiades Publishing, Ltd.

Scopus,
WOS

Держатели документа:
Institute of Biophysics, Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences, AkademgorodokKrasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation
Institute of Computational Modeling, Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences, AkademgorodokKrasnoyarsk, 660036, Russian Federation
Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences, AkademgorodokKrasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Ronzhin, N. O.; Posokhina, E. D.; Mikhlina, E. V.; Simunin, M. M.; Nemtsev, I. V.; Ryzhkov, I. I.; Bondar, V. S.