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NMR diffusion studies of proton-exchange membranes in wide temperature range
Journal of Membrane Science. 2020. Vol. 596. Article 117691.
Galitskaya E., Privalov A., Weigler M., Vogel M., Vitaly Sinitsyn
It is established that the values of the coefficients of self-diffusion of water in proton-exchange membranes at a fixed temperature and the amount of moisture content depend on the method of membrane manufacture, the length of the side chain (diameter of channels), but within the experimental error do not depend on the thickness of the membrane. It is shown that at low hydration, a "short-chain" membrane is more preferable for practical use in a fuel cell than a membrane with a long side chain.
Veretennikov A., Moscow Mathematical Journal 2024 Vol. 24 No. 1 P. 107–124
Second order recurrence are established for a d-dimensional diffusion with an additive Wiener process, with switching, and with one recurrent and one transient regime and constant switching intensities, under suitable conditions. As a corollary, the rate of convergence towards the invariant regime of order t^{−2} is claimed. The approach is based on embedded Markov chains ...
Added: July 16, 2026
Veretennikov A., Stochastics and Partial Differential Equations: Analysis and Computations 2022 Vol. 10 P. 1165–1179
Positive recurrence of a $d$-dimensional diffusion with an additive Wiener process, with switching and with one recurrent and one transient regimes and variable switching intensities is established under suitable conditions. The approach is based on embedded Markov chains. ...
Added: July 15, 2026
Pushkareva I., Wu Z., Liu X. et al., ACS Applied Materials & Interfaces 2025 Vol. 17 No. 22 P. 32216–32227
Electrolytic hydrogen production using abundantwater and renewable electricity is a key step toward achieving a carbon-neutral economy.Anion-exchange membrane water electrolyzers AEMWE)present an opportunity toenhance sustainability and reduce the costs of green hydrogen technology. This studyfocuses on reducing electrical losses in the AEMWE by designing an improved anode catalyst layer. The approach involves modifying nickel foam ...
Added: March 9, 2026
Fominykh N., Stegailov V., Journal of Chemical Physics 2025 Vol. 163 No. 11 Article 114704
First-principles modeling of exciton dynamics coupled with lattice vibrations is important for understanding exciton mobility, which is crucial for various applications. In order to shed light on such coupled exciton–lattice dynamics, in this paper, we use a restricted open-shell Kohn–Sham approach, which is a computationally efficient method for electronic structure calculations in the lowest excited ...
Added: September 16, 2025
Kazantsev K., Toukach P., International Journal of Biological Macromolecules 2024 Vol. 282 Article 137042
Primary structure elucidation in glycobiology is strongly affected by published structure-reporting NMR signals, especially on the 13C nucleus. The glycan NMR simulation accuracy and machine learning outcome depend on the quality of the NMR signal assignment in glycan databases. Within our work on improving the data quality in the Carbohydrate Structure Database (CSDB), we have ...
Added: November 13, 2024
Ivchenko N., Lebedev V., Vergeles S. S., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2024 Vol. 110 No. 1 Article 015102
Chaotic variations in flow speed up mixing of scalar fields via intensified stirring. This paper addresses the statistical properties of a passive scalar field mixing in a regular shear flow with random fluctuations against its background. We consider two-dimensional flow with shear component dominating over smooth fluctuations. Such flow is supposed to model passive scalar ...
Added: September 3, 2024
Khnkoian G. V., Nikolaev V. S., Stegailov V., Journal of Nuclear Materials 2024 Vol. 594 Article 155016
Microscopic description of solid Pb-O formation and dissolution in liquid lead coolant is important for the modelling of fast neutron reactors. For this purpose, in this work we develop interatomic potential models for lead melt with dissolved oxygen. Potentials fitting is based on \textit{ab initio} density functional theory (DFT) calculations and quantum molecular dynamics. Two ...
Added: April 18, 2024
Magnetic properties of LiCu3O3: A quasi-two-dimensional antiferromagnet on a depleted square lattice
Bush A. A., S. K. Gotovko, Ivanov V. Y. et al., Physical Review B: Condensed Matter and Materials Physics 2024 Vol. 109 No. 11 Article 115151
LiCu3O3 is a novel two-dimensional S=1/2 antiferromagnet with randomly depleted square lattice. The crystal structure contains two types of square planes with different Cu2+→Li+ substitution rates (20% and 40%). 7Li NMR and magnetization measurements performed on single crystals of LiCu3O3 revealed the occurrence of magnetic order at Tc1=123K and the change of the magnetic state ...
Added: March 27, 2024
Ivchenko N., Vergeles S. S., Журнал экспериментальной и теоретической физики 2023 Т. 163 № 5 С. 724–733
We study statistical properties of the passive scalar advection in a 2D flow that consist of a steady-state shear flow and a relatively weak smooth random component taking into account the effects of finite weak diffusion. The model is closely related to the dynamics of passive scalar transfer inside coherent vortices emerging as a result ...
Added: February 15, 2024
Privalov A., Vitaly V. Sinitsyn, Vogel M., The Journal of Physical Chemistry Letters 2023 Vol. 14 No. 30 P. 9335–9340
We use 1H and 17O NMR static field gradient diffusometry to measure self-diffusion coefficients of protons (DH) and oxygens (DO) in Nafion 212 with various hydration levels (λ = 4–18). For all samples and both nuclei, we obtain activation energies (Ea) of ≈0.19 eV. Analyzing the hydration-level dependence of DH and DO, we find DO/DH ≈ 1 at λ ≈ 18, resembling ...
Added: October 13, 2023
Darya Gurina, Ekaterina Odintsova, Krestyaninov M. A. et al., Journal of Molecular Liquids 2023 Vol. 390 No. A Article 122961
The paper presents a study of the behavior of room-temperature ionic liquids with different alkyl chain lengths and anion types in slit negatively charged carbon nanopores of various widths (1÷15 nm) using all-atom molecular dynamics simulations. The structure of the confined ionic liquids is investigated using number, mass, and charge density profiles and radial distribution ...
Added: August 31, 2023
Panina I., Balandin S., Tsarev A. et al., International Journal of Molecular Sciences 2023 Vol. 24 No. 2 P. 1
To date, a number of lantibiotics have been shown to use lipid II — a highly conserved peptidoglycan precursor in the cytoplasmic membrane of bacteria — as their molecular target. The α-component (Lchα) of the two-component lantibiotic lichenicidin (Lchα), previously isolated from the Bacillus licheniformis VK21 strain, seems to contain two putative lipid II binding ...
Added: February 21, 2023
Antropov A., Stegailov V., Journal of Nuclear Materials 2023 Vol. 573 Article 154123
The influence of helium pressure on the mechanisms of diffusion of the He-filled nanobubbles in fcc Al is investigated by the classical molecular dynamics. It is shown that at pressures <20 kbar gas suppresses self-diffusion, while the concentration of adatoms, rather than their mobility, plays a key role. However, as the pressure increases to values at which ...
Added: February 1, 2023
Гнесин И. Б., Поверхность. Рентгеновские, синхротронные и нейтронные исследования 2022 № 1 С. 63–74
In this work, the kinetics of diffusion interaction of the molybdenum silicides Mo5Si3 + MoSi2 alloy with the zirconium-based E110 alloy is experimentally investigated. The structure and phase composition of diffusion couples subjected to vacuum annealing at 1100, 1200, and 1300°C for 3, 6, and 9 hours have been studied by scanning electron microscopy and ...
Added: October 29, 2022
Alekseev I., Kraev G., Shein A. et al., Energies 2022 Vol. 15 No. 6 Article 2301
Various research issues related to soil organic matter in permafrost soils are still poorly investigated. At the same time, numerous investigations have shown the importance of permafrost soils, as they serve as a huge reservoir of organic matter. This work is aimed at the investigation of permafrost-affected soils in the southern part of the Yamal ...
Added: October 26, 2022
Дещеня В. И., Kondratyuk N., Ланкин А. В. et al., Журнал физической химии 2022 Т. 96 № 3 С. 373–380
The temperature dependence of density is calculated for an aqueous solution of sucrose by the molecular dynamics method. The coefficients of viscosity and diffusion are also obtained in the 273–343 K range of temperatures. The hydrodynamic radius of a sucrose molecule in an aqueous solution is calculated. The obtained data are compared with the experimental ...
Added: October 24, 2022
Zavorotnaya U., Igor I. Ponomarev, Volkova Y. et al., Materials 2020 Vol. 22 No. 13 Article 5297
The sulfonated polynaphthoyleneimide polymer (co-PNIS70/30) was prepared by copolymerization of 4,4′-diaminodiphenyl ether-2,2′-disulfonic acid (ODAS) and 4,4’-methylenebisanthranilic acid (MDAC) with ODAS/MDAC molar ratio 0.7/0.3. High molecular weight co-PNIS70/30 polymers were synthesized either in phenol or in DMSO by catalytic polyheterocyclization in the presence of benzoic acid and triethylamine. The titration reveals the ion-exchange capacity of the polymer ...
Added: October 20, 2022