Structural defects and heteroatoms play a key role in electrochemical reactions. However, there is still no common understanding of what has a greater impact on electrochemical processes: defects or the type of heteroatoms. To clarify these factors, defective carbon nanowalls treated by reactive etching in different atmospheres, such as argon and mixtures of argon with nitrogen, chlorine, hydrogen bromide, and sulfur fluoride were used. Properties of the obtained samples were analyzed with Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and cyclic voltammetry. The results of the study showed that the plasma modification of carbon nanowalls leads to the removal of the amorphous layer and subsequent implantation of heteroatoms, which ultimately leads to an increase in their areal capacitance 1.5-fold in a 1:2 argon - nitrogen mixture and 2-fold in a 1:4 argon-nitrogen mixture.

Two-dimensional C60 carbon allotropes have gained much attention since their first synthesis in 2022, but many of their thermophysical and mechanical properties remain unreported in the literature. In this article, we performed a high-temperature molecular dynamics study of quasi-hexagonal (qHP) and quasi-tetragonal (qTP) C60 phases using the modern machine-learning interatomic potential GAP-20. We show that, contrary to previous calculations, at T>1200 K, both phases are unstable and decompose into individual C60 molecules. A low bending modulus indicates the possibility of nanoripple excitation at high temperatures, similar to those in graphene. We also demonstrate the crucial role of interatomic potential verification for MD analysis of previously unexplored carbon allotropes.

Graphene oxide (GO) is a promising membrane material due to its high water permeability. However, the exact physical mechanisms governing this process at the molecular level remain poorly understood, despite more than a decade of practical applications. In this article, we use classical molecular dynamics with the reactive potential ReaxFF to study the mobility of water molecules intercalated in GO and analyze the influence of its structure on diffusion processes. We highlight the previously unmentioned role of the interfacial area between oxidized and pristine graphene regions, which, according to our calculations, may be responsible for the ultrafast water transport observed in GO. This diffusion exhibits characteristics of a ballistic regime, suggesting another possible mechanism underlying GO’s high water permeability.

van der Waals (vdW) materials are becoming increasingly popular in scientific and industrial applications because of their unique mixture of record electronic, optical, and mechanical properties. However, nanostructuring of vdW materials is still in its infancy and strongly depends on the specific vdW crystal. As a result, the universal self-assembled technology of vdW materials nanostructuring opens vast technological prospects. This work demonstrates an express and universal synthesis method of vdW nanoparticles with well-defined geometry using femtosecond laser ablation and fragmentation. The disarming simplicity of the technique allows us to create nanoparticles from over 50 vdW precursor materials, covering transition metal chalcogenides, MXenes, and other vdW materials. Obtained nanoparticles manifest perfectly defined crystalline structures and diverse shapes, from nanospheres to nanocubes and nanotetrahedrons. Thus, our approach illustrates a generalizable route to vdW nanostructuring with broad tunability in size, shape, and material composition, adaptable to specific application requirements.

Herein, we obtained two supramolecular assemblies with layered structures from melamine, N-methylmelamine, and hexynyl-cyanuric acid in water. By combination of X-ray diffraction, electron microscopy, and molecular dynamics studies, we found that introducing one methyl group in melamine alters the arrangement of the layers in these structures.

Graphene oxide is a popular material because of not only its cost-efficient production but also its unique properties. However, after long-term storage, several changes occur in the structure of graphene oxide obtained using the modified Hummers' method, affecting its stability and physicochemical properties. Despite the obvious problem, there is only a limited number of works devoted to ageing factors, their impact on the properties and structure of graphene oxide itself, and operational modes of materials and devices based on graphene oxide. Therefore, to facilitate the widespread industrial application of graphene oxide, it is crucial to establish standardized protocols for storage and quality assessment of graphene oxide. In this paper, the prepared samples were extensively characterized using various techniques, including transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis and fluorescence spectroscopy techniques. Among the various analytical methods, comprehensive spectroscopic analysis of the absorption and fluorescence properties has proven to be the most sensitive to sample ageing. We investigated the change in optical and physicochemical properties of graphene oxide during its long-term storage under various conditions. It was found that graphene oxide precipitated during storage, and the O/C ratio in graphene oxide decreased slightly from 0.49 to 0.47. Still, the type of oxygen-containing functional groups did not change, which might indicate possible intra-structural changes. Using transmission electron microscopy, molecular dynamic and density functional theory simulation, we showed that the rearrangement of functional groups on the surface leads to the formation of large sp2 domains that interact with each other, leading to aggregation of the graphene oxide.

A containerless chemical reaction observed in a levitating droplet cluster for the first time is used for information processing.

Utilizing classical molecular dynamics with the precise machine-learning interatomic potential MTP, we investigated the high-temperature (3000-3500 K) dynamics of NV and N2V centers in the presence of additional free vacancies. We propose a novel mechanism for nitrogen diffusion in diamond, which involves the intermediate step of additional vacancies being absorbed by a NV center. The simulation results align with the experimentally observed transformations of NV centers into H1b and H1c in IaAB-diamond under 4.7-mu m femtosecond-laser irradiation.

As a soot particle grows, it undergoes a number of significant morphological changes (called aging), which lead to a decrease in reactivity of the particle surface. This work uses reactive molecular dynamics to study the interaction between acetylene molecules in the gas phase and the surface of soot particles of varying degrees of maturity. It is demonstrated that the branched morphology of “young” soot particles and the presence of nanosized voids on their surface can be another effect that has a significant impact on the higher reactivity of soot particles.

Vacuum fluctuations are a fundamental and irremovable property of a quantized electromagnetic field. These fluctuations are the cause of the Casimir effect-mutual attraction of two electrically neutral metallic plates in vacuum in the absence of any other interactions. For most geometries and materials, the Casimir effect is strictly attractive, leading to the only stable equilibrium configuration with merged plates. Recent observation showed, however, that this unavoidable vacuum-induced attraction can be mitigated by the presence of electrostatic repulsion produced by the formation of double electric layers, and a stable equilibrium between two charged metallic plates in a solution of an organic salt can be reached Munkhbat et al., Nature (London) 597, 214 (2021). Here, we study theoretically in detail equilibrium configurations and their dynamical behavior in the system of two parallel metallic films coupled by the Casimir and electrostatic interactions. We analyze the effect of various parameters of the system-such as the salt concentration and temperature-on the equilibrium cavity thicknesses, inspect resonant properties of the resulting optomechanical system near equilibrium, and examine its stochastic dynamics under thermal fluctuations of the environment.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

In this work, we considered the formation of supramolecular assemblies of melamine-thiobarbiturate and melamine-barbiturate-thiobarbiturate. It is known that thiobarbituric acid can form many tautomers, as well as different motifs due to the change of C2=O to C2=S hydrogen bonds. We formed the crystal. The resulting crystals were studied with scanning electron microscopy (SEM), optical fluorescence microscopy, single crystal and powder (PXRD) X-ray diffraction analyses, and solid state nuclear magnetic resonance (ss NMR). These systems were theoretically studied using density functional theory (DFT) and classical molecular dynamics (MD) simulations. Interestingly, just as in the case of melamine barbiturate, during the crystallization process, hydrogen from the C5 moiety of thiobarbituric acid migrates to the melamine molecule. In addition, the resulting melamine thiobarbiturate crystals exhibit fluorescence behavior in the red region (~565–605 nm), while the melamine barbiturate crystals are fluorescent in the green region (512–542 nm).

Understanding the mechanisms of soot formation and decomposition is important for reduction of harm-ful emissions from combustion. Soot sublimation temperature varies in a wide range from approximately 250 0 to 450 0 K and the fundamental reasons for such drastic discrepancy are still unknown. To shed light on the relationship between soot morphology and its sublimation temperature and to study the molecular products of its sublimation we model thermal decomposition of soot using reactive molecu-lar dynamics simulations. Our results show that besides well-known low-molecular-weight C1 -C5 species soot can also decompose into graphene-like products with mass up to 30 0-60 0 Da. Mass distribution of the sublimation products strongly depends on the morphology of the particle which in turn depends on the conditions at which the particle was formed. Moreover we demonstrate that those soot particles which can withstand temperatures up to 30 0 0 K undergo fast annealing and sintering which additionally enhances their thermal stability.(c) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Our ability to synthesize life-inspired systems and materials is mately connected to our understanding of the interplay between actions, diffusion, phase separation, and self-assembly. The interaction between non-linear reactions (autocatalysis) and liquid-liquid phase separation is particularly interesting because of the emergence of functional properties and structures through instabilities, which are hard to predict theoretically without the help of experimental model systems. In this work, we studied systems where chemical autocatalysis is coupled to complex coacervation and formation of oil-in-water droplets. The autocatalysis is driven by nucleophilic chain reaction and is coupled to complex coacervation through the formation of tri-and tetracationic species. Interestingly, we observed the formation of hierarchical colloids when we used actants that can form oil droplets in addition to coacervate droplets. This work illustrates a mechanism for the formation of complex, erarchical microstructures by kinetically controlled self-assembly regulated by non-linear chemical reaction networks.

По мере роста сажевая частица претерпевает ряд существенных морфологических изменений (называемых "старением"), которые приводят к снижению реакционной способности поверхности частицы. В данной статье с помощью метода реакционной молекулярной динамики исследуется взаимодействие между молекулами ацетилена, находящимися в газовой фазе, и поверхностью сажевых частиц различной степени зрелости. Продемонстрировано, что разветвленная морфология "молодых" сажевых частиц и наличие наноразмерных полостей на их поверхности может являться еще одним эффектом, оказывающим весомое влияние на более высокую реакционную способность сажевых частиц.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

AbstractIn this paper, we introduce a novel encapsulation system for DNA oligonucleotides. Supramolecular assembly of melamine cyanurate encapsulates DNA at pH 7 and start to release it at pH less than 6.5. We study the assembly and disassembly in time in specially designed reaction‐diffusion system. Magnesium ions allow spatial separation of DNA with the highest DNA concentration in the core of melamine cyanurate capsule. Molecular dynamics (MD) simulation shows that DNA acts as a nucleation centre for melamine cyanurate. Dataset of fluorescent images analysed by machine learning algorithms indicates correlation between structure of melamine cyanurate capsules for DNA trapping and concentration of magnesium ions. The concentration of magnesium ions can be recognized with 96% accuracy proving that all environmental conditions are extremely important during the self‐assembly and should be considered for laboratory and industrial applications of the suggested approach. Moreover, the encapsulated DNA can undergo a cascade reaction consisting of hybridization with complementary strand and its cleavage at a designated site. This reactivity opens a fresh avenue for various applications in biosensing, diagnostics, DNA compartmentalization, and even gives new hints for the origin‐of‐life questions.

Search for a cheap and efficient route of graphene fabrication is still far from its conclusion, and reduction of graphene oxide (GO) is considered one of the most promising ways to achieve this goal. Here we perform combined experimental and computational analysis of a simple yet efficient and environment-friendly method for reducing GO using nanosecond infrared laser irradiation, which can be performed under ambient conditions and does not require an inert atmosphere or vacuum. We demonstrate that ultrafast heating up to 3800 K leads to a fascinating regime of high quality GO reduction even in the presence of atmospheric air. This surprising effect is achieved as an interplay between two seemingly opposite processes: combustion on the highly-defective areas of GO, such as grain boundaries, and defect annealing in its bulk part. As a result, under particular pulse regimes, after a small loss of mass (primarily from its edges), GO transforms into rGO with a high local order and low Raman I(D)/I(G) ratio. (c) 2022 Elsevier Ltd. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Liquid carbon remains the source of several unsolved questions related to its structure and region of thermodynamic stability. Experiments demonstrate a drastic decrease in the density for liquid carbon along the graphite melting line in the pressure range P = 1-3 GPa and the nature of this phenomenon is unclear. A recent experimental study [A.M. Kondratyev and A.D. Rakhel, PRL (2019)] revealed another peculiar and still unexplained feature of the liquid carbon e its excessive heat capacity. Using classical molecular dynamics with machine learning potential GAP-20, we study the structural properties of liquid carbon and demonstrate that at P < 1-2 GPa it resembles a net of sp-hybridized chains, rather than a typical covalent liquid, with nanoscale porosity of this phase being responsible for the density decrease. We also show that excessive heat capacity could be a direct manifestation of a smooth transition from a high-density sp(2)-hybridized phase into a low-density sp-hybridized. (C) 2022 Elsevier Ltd. All rights reserved.