Труды сотрудников ИВМ СО РАН

/ I. I. Ryzhkov, A. V. Minakov // J. Membr. Sci. - 2016. - Vol. 520. - P515-628, DOI 10.1016/j.memsci.2016.08.004 . - ISSN 0376-7388
Аннотация: The pressure–driven electrolyte transport through nanofiltration membrane pores with constant surface potential or charge density is investigated theoretically. Two approaches are employed in the study. The first one is based on one–dimensional Nernst–Planck equation coupled with electroneutrality, zero current, and Donnan equilibrium conditions. This model is extended to account for interfacial effects by using a smooth approximation of step function for the volume charge density. The second approach is based on two–dimensional Nernst–Planck, Poisson, and Navier–Stokes equations, which are solved in a high aspect ratio nanopore connecting two reservoirs with much larger diameter. The modification of equations on the basis of Slotboom transformation is employed to speed up the convergence rate. The distributions of potential, pressure, ion concentrations and fluxes due to convection, diffusion, and migration in the nanopore and reservoirs are discussed and analyzed. It is found that for constant surface charge density, the convective flux of counter–ions in the nanopore is almost completely balanced by the opposite migration flux, while for constant surface potential, the convective flux is balanced by the opposite diffusion and migration fluxes. The co–ions in the nanopore are mainly transported by diffusion. A particular attention is focused on describing the interfacial effects at the nanopore entrance/exit. Detailed comparison between one– and two–dimensional models is performed in terms of rejection, pressure drop, and membrane potential dependence on the surface potential/charge density, volume flux, ion concentration, and pore radius. A good agreement between these models is found when the Debye length is smaller than the pore radius and the surface potential or charge density are sufficiently low. © 2016 Elsevier B.V.

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Держатели документа:
Institute of Computational Modelling SB RAS, Akademgorodok, Krasnoyarsk, Russian Federation
Siberian Federal University, Svobodny 79, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Minakov, A. V.; Рыжков, Илья Игоревич

/ I. I. Ryzhkov [et al.] // J. Membr. Sci. - 2018. - Vol. 549. - P616-630, DOI 10.1016/j.memsci.2017.11.073. - Cited References:69. - This work is supported the Russian Science Foundation, Project 15-19-10017. The physicochemical analysis of materials was carried out on the equipment of Krasnoyarsk Scientific Center of Shared Facilities SB RAS. . - ISSN 0376-7388. - ISSN 1873-3123РУБ Engineering, Chemical + Polymer Science

Аннотация: We report a new mechanism for the generation of membrane potential in polarizable nanoporous membranes separating electrolytes with different concentrations. The electric field generated by diffusion of ions with different mobilities induces a non-uniform surface charge, which results in charge separation inside the nanopore. The corresponding Donnan potentials appear at the pore entrance and exit leading to a dramatic enhancement of membrane potential in comparison with an uncharged non-polarizable membrane. At high concentration contrast, the interaction between electric field and uncompensated charge at a low concentration side results in the development of electrokinetic vortices. The theoretical predictions are based on the Space-Charge model, which is extended to nanopores with polarizable conductive surface for the first time. This model is validated against full Navier-Stokes, Nernst-Planck, and Poisson equations, which are solved in a high aspect ratio nanopore connecting two reservoirs. The experimental measurements of membrane potential of dielectric and conductive membranes in KCl and NaCl aqueous solutions confirm the theoretical results. The membranes are prepared from Nafen nanofibers with similar to 10 nm in diameter and modified by depositing a conductive carbon layer. It is shown theoretically that the membrane potential enhancement becomes greater with decreasing the electrolyte concentration and pore radius. A high sensitivity of membrane potential to the ratio of ion diffusion coefficients is demonstrated. The described phenomenon may find applications in precise determination of ion mobilities, electrochemical and bio-sensing, as well as design of nanofluidic and bioelectronic devices.

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Держатели документа:
Fed Res Ctr KSC SB RAS, Inst Computat Modelling SB RAS, Akademgorodok 50-44, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, Svobodny 79, Krasnoyarsk 660041, Russia.

Доп.точки доступа:
Ryzhkov, Ilya I.; Lebedev, Denis V.; Solodovnichenko, Vera S.; Minakov, Andrey V.; Simunin, Mikhail M.; Russian Science Foundation [15-19-10017]

[Text] : статья / Ilya I. Ryzhkov, Anton S. Vyatkin, Andrey V. Minakov // Журнал Сибирского федерального университета. Серия: Математика и физика. - 2018. - Т. 11, № 4. - P494-504, DOI 10.17516/1997-1397-2018-11-4-494-504 . - ISSN 1997-1397
   Перевод заглавия: Теоретическое исследование диффузии электролитов через поляризуемые нанопоры

УДК	532.711 + 66.081.6

Аннотация: The diffusion of binary aqueous electrolytes through nanopores with dielectric as well as conductive surface is investigated theoretically on the basis of Space-Charge model. The latter is extended to the case of polarizable nanopore wall. It is shown that the diffusion of ions with different mobilities generates the electric field, which induces non-uniform surface charge in a polarizable nanopore. It results in charge separation inside the pore and leads to a dramatic enhancement of membrane potential in comparison witha non-polarizable nanopore. Thecalculations areperformed for three aqueous electrolytesbased on KCl, NaCl, and LiOH. The influence of electrolyte type and concentration difference applied across the pore on the ion transport and membranepotential is discussed and analyzed.
Проведено теоретическое исследование диффузии бинарных электролитов через нанопоры с диэлектрической,а также проводящей поверхностью на основе модели пространственного заряда. Данная модель обобщена наслучай поляризумой стенки порыспостоянным потенциалом. Показано, что диффузия ионовсразличными подвижностями приводитк возникновениюэлектрического поля, которое индуцирует неравномерное распределение заряда на поверхности проводящей поры. Это вызывает разделение заряда внутри поры и приводит к значительному увеличению мембранного потенциала по сравнению сослучаемдиэлектрической поры. Проведенырасчеты для трех типов водных электролитов на основе KCl, NaCl и LiOH. Исследовано влияние типа электролитаитрансмембраннойразности концентрацийна перенос ионовимембранный потенциал.

РИНЦ

Держатели документа:
Institute of Computational Modelling SB RAS
Institute of Engineering Physics and Radio Electronics Siberian Federal University
Siberian Federal University

Доп.точки доступа:
Ryzhkov, Ilya I.; Рыжков, Илья Игоревич; Vyatkin, Anton S.; Вяткин Антон С.; Minakov, Andrey V.; Минаков Андрей В.

/ Y. N. Zaitseva [и др.] // J. Sib. Fed. Univ.-Chem. - 2019. - Vol. 12, Is. 3. - С. 395-404, DOI 10.17516/1998-2836-0136. - Cited References:19 . - ISSN 1998-2836. - ISSN 2313-6049РУБ Chemistry, Multidisciplinary

Аннотация: Mesostructured carbon material CMK-3 for electrodes of electrochemical capacitors was obtained by the method of template synthesis. In order to increase the capacitance characteristics, impregnation of metal ions (Co, Ni, and Cu) into the structure of mesoporous carbon CMK-3 was carried out. The structure of the obtained materials was studied by X-ray diffraction and gas adsorption. The study by TEM showed that highly dispersed, nanosized particles are metal oxides Co, Ni and Cu with the size of 30-50 nm. The particles are uniformly distributed inside the carbon material. Electrochemical characteristics were studied in aqueous electrolytes (1M KCl and 1M KOH). It has been established that the impregnation of metal ions increases in the specific capacity of the mesoporous carbon material by about 30 % (from 110 to 156 F/g) in KOH.

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Держатели документа:
FRC Krasnoyarsk Sci Ctr SB RAS, Inst Chem & Chem Technol SB RAS, 50-24 Akademgorodok, Krasnoyarsk 660036, Russia.
FRC Krasnoyarsk Sci Ctr SB RAS, Inst Computat Modeling SB RAS, 50-44 Akademgorodok, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, 79 Svobodny, Krasnoyarsk 660041, Russia.

Доп.точки доступа:
Zaitseva, Yulia N.; Novikova, Svetlana A.; Parfenov, Vladimir A.; Vyatkin, Anton S.; Ryzhkov, Ilya I.

/ A. P. Gavrilyuk [et al.] // Colloid Polym. Sci. - 2019, DOI 10.1007/s00396-019-04573-8 . - Article in press. - ISSN 0303-402X
Аннотация: The Brownian dynamics method is employed to study the formation of an electrical double layer (EDL) on the metal nanoparticle (NP) surface in hydrosols during adsorption of electrolyte ions from the interparticle medium. Also studied is the charge accumulation by NPs in the Stern layer. To simulate the process of the formation of EDL, we took into account the effect of image forces and specific adsorption, dissipative and random forces, and the degree of hydration of adsorbed ions on the EDL structure. The employed model makes it possible to determine the charge of NPs and the structure of EDL. For the first time, the charge of both the diffuse part of EDL and the dense Stern layer has been determined. A decrease in the electrolyte concentration (below c < 0.1 mol/l) has been found to result in dramatic changes in the formation of the Stern layer. [Figure not available: see fulltext.]. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

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Держатели документа:
Institute of Computational Modeling SB RAS, Krasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation
L. V. Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, 660036, Russian Federation
Siberian State University of Science and Technology, Krasnoyarsk, 660014, Russian Federation

Доп.точки доступа:
Gavrilyuk, A. P.; Isaev, I. L.; Gerasimov, V. S.; Karpov, S. V.