Melting simulations of high-entropy carbonitrides by deep learning potentials.

The melting temperature is a crucial property of materials that determines their potential applications in different industrial fields. In this study, we used a deep neural network potential to describe the structure of high-entropy (TiZrTaHfNb)CN carbonitrides (HECN) in both solid and liquid states. This approach allows us to predict heating and cooling temperatures depending on the nitrogen content to determine the melting temperature and analyze structure changes from atomistic point of view.

Chemical bonding within AB materials under uniaxial compression.

The work provides a comprehensive explanation of the nature of chemical bonding through quantum chemical topology for multilayers of AB compounds, such as GaSe, InSe, and GaTe, spanning pressures from 0 GPa to 30 GPa. These compounds are subjected to pressure orthogonal to the multilayers. Quantum chemical topological indices indicate that uniaxial pressure induces changes in hybridisation, leading to the disappearance of interlayer van der Waals forces.

Cytotoxicity and Degradation Resistance of Cryo- and Hydrogels Based on Carboxyethylchitosan at Different pH Values.

The use of chitosan-based gels is still limited due to their restricted solubility in acid solutions, where the molecules have a positive charge. The functionalization of chitosan makes it possible to significantly expand the possibilities of using both the polymer itself and hydrogels based on its derivatives. To evaluate the effect of the conditions for the production of cryo- and hydrogels based on carboxyethylchitosan (CEC) crosslinked with glutaraldehyde on gel swelling and its resistance to degradation depending on pH and cytotoxic effects and to test the hypothesis that the amount of crosslinking agent during synthesis may affect the cytotoxicity of the gel.

Recrystallization of Cellulose, Chitin and Starch in Their Individual and Native Forms.

Semi-crystalline natural polymers are involved in many technological processes. Biopolymers having identical chemical compositions can differ in reactivity in heterogeneous transformations depending on their crystal structure (polymorphic modification). This paper compares the crystal structure recrystallization processes occurring in natural polysaccharides (cellulose, chitin, and starch) in the individual form and as a component of native biomass.

Determining the quantum yield of photochemical reactions in crystals from simultaneous effects of photothermal and photochemical bending of needle-shaped crystals.

Photoinduced bending of needle crystals caused by photochemical transformation can be used as an extremely sensitive method for studying the kinetics of the transformation. However, the determination of the absolute value of the quantum yield of the reaction requires an accurate value of the intensity of light penetrating the crystal, in contrast to reactions in solutions where only the value of the total absorbed irradiation dose is sufficient. To address this problem, this study utilizes the effect of photothermal bending of a crystal due to its heating by light, occurring simultaneously with the bending due to transformation and proportional to the same value of light intensity.

Ultrafast Polarization Switching in BaTiO Nanomaterials: Combined Density Functional Theory and Coupled Oscillator Study.

The challenge of achieving ultrafast switching of electric polarization in ferroelectric materials remains unsolved as there is no experimental evidence of such switching to date. In this study, we developed an enhanced model that describes switching within a two-dimensional space of generalized coordinates at THz pulses. Our findings indicate that stable switching in barium titanate cannot be achieved through a single linearly polarized pulse.

Constrained DFT-based magnetic machine-learning potentials for magnetic alloys: a case study of Fe-Al.

We propose a machine-learning interatomic potential for multi-component magnetic materials. In this potential we consider magnetic moments as degrees of freedom (features) along with atomic positions, atomic types, and lattice vectors. We create a training set with constrained DFT (cDFT) that allows us to calculate energies of configurations with non-equilibrium (excited) magnetic moments and, thus, it is possible to construct the training set in a wide configuration space with great variety of non-equilibrium atomic positions, magnetic moments, and lattice vectors.

A Carboxyethylchitosan Gel Cross-Linked with Glutaraldehyde as a Candidate Carrier for Biomedical Applications.

To date, few publications describe CEC's properties and possible applications-thus, further evaluation of these properties is a point of interest. The present in vitro model study aimed to evaluate a carboxyethylchitosan (CEC) gel with a degree of substitution of 1, cross-linked with glutaraldehyde at a polymer:aldehyde molar ratio of 10:1, as a potential carrier for delivering bacteriophages to various pH-fixed media (acidic, alkaline), and including gastrointestinal tract (GIT) variable medium. A quantitative analysis of bacteriophages released from the gel was performed using photon correlation spectrophotometry, and phage activity after emission into medium was evaluated using the spot test.

Synthesis of Tungsten Carbides in a Copper Matrix by Spark Plasma Sintering: Microstructure Formation Mechanisms and Properties of the Consolidated Materials.

In this study, the synthesis of tungsten carbides in a copper matrix by spark plasma sintering (SPS) is conducted and the microstructure formation mechanisms of the composite materials are investigated. The reaction mixtures were prepared by the high-energy mechanical milling (MM) of W, C and Cu powders. The influence of the MM time and SPS temperature on the tungsten carbide synthesis in an inert copper matrix was analyzed.

High-Conductive CsHPO Membranes with PVDF-Based Polymers Additives.

The study is devoted to one of the important problems of hydrogen energy-the comparative analysis and creation of novel highly conductive and durable medium-temperature proton membranes based on cesium dihydrogen phosphate and fluoropolymers. The proton conductivity, structural characteristics and mechanical properties of (1 - x)CsHPO-x fluoropolymer electrolytes (x-mass fraction, x = 0-0.3) have been investigated and analyzed.

Hybrid Nanocomposite Solid Electrolytes (n-CH)NBF-MgO.

Hybrid nanocomposite materials BuNBF-MgO were obtained using a nanocrystalline MgO with a specific surface area of 324 m/g and the grains size of 5.1 nm. As a result of the strong adhesion, the salt transforms into an interface-stabilized amorphous state within the thin layer near the interface.

Synthesis and Oxygen Mobility of Bismuth Cerates and Titanates with Pyrochlore Structure.

Synthesis and study of materials based on bismuth cerates and titanates were carried out. Complex oxides BiYTiO were synthesized by the citrate route; BiCeO and BiYCeO-by the Pechini method. The structural characteristics of materials after conventional sintering at 500-1300 °C were studied.

Disordering of Starch Films as a Factor Influencing the Release Rate of Biologically Active Substances.

The release of a spin probe (nitroxide radical) from polymer films was studied by electron paramagnetic resonance (EPR). The films were fabricated from starch having different crystal structures (A-, B-, and C-types) and disordering degrees. Film morphology (analysis of the scanning electron microscopy (SEM)) depended on the presence of dopant (nitroxide radical) to a larger extent rather than on crystal structure ordering or polymorphic modification.

Copolymer of VDF/TFE as a Promising Polymer Additive for CsHPO-Based Composite Electrolytes.

The composite polymer electrolytes (1-x)CsHPO-xF-2M (x = 0-0.3) have been first synthesized and their electrotransport, structural, and mechanical properties were investigated in detail by impedance, FTIR spectroscopy, electron microscopy, and X-ray diffraction methods. The structure of CsHPO (P2/m) with salt dispersion is retained in the polymer electrolytes.

Silver nanoparticle-modified melt-blown polypropylene: Antibacterial and antifungal properties and antiviral activity against SARS-CoV-2.

Melt-blown polymer fiber materials are frequently used in the face mask manufacturing. In the present work, a melt-blown polypropylene tape was modified by silver nanoparticles using chemical metallization. The silver coatings on the fiber surface consisted of crystallites 4-14 nm in size.

Crystal Chemistry and Ionic Conductivity of the NASICON-Related Phases in the LiNaV(PO) System.

In the present work, we studied crystal phases in the LiNaV(PO) system over a wide range of prepared by four synthesis methods: mechanochemically assisted solid-state synthesis, 'soft chemistry' sol-gel approach, chemical (CIE) and electrochemical (EIE) ion exchange starting from LiV(PO) (anti-NASICON, 2/ S.G.), and NaV(PO) (NASICON, 2/ S.

Electronic Properties of Functionalized Diamanes for Field-Emission Displays.

Ultrathin diamond films, or diamanes, are promising quasi-2D materials that are characterized by high stiffness, extreme wear resistance, high thermal conductivity, and chemical stability. Surface functionalization of multilayer graphene with different stackings of layers could be an interesting opportunity to induce proper electronic properties into diamanes. Combination of these electronic properties together with extraordinary mechanical ones will lead to their applications as field-emission displays substituting original devices with light-emitting diodes or organic light-emitting diodes.

Formation of Metal-Oxide Nanocomposites with Highly Dispersed Co Particles from a Co-Zr Powder Blend by Mechanical Alloying and Hydrogen Treatment.

The use of metal powders produced by mechanical treatment in various fields, such as catalysis or gas absorption, is often limited by the low specific surface area of the resulting particles. One of the possible solutions for increasing the particle fineness is hydrogen treatment; however, its effect on the structure of mechanically treated powders remains unexplored. In this work, for the first time, a metal-oxide nanocomposite powder was produced by mechanical alloying (MA) in a high-energy planetary ball mill from commercial powders of Zr and Co in the atomic ratio Co:Zr = 53:47 in an inert atmosphere, followed by high-pressure hydrogenation at room temperature.

Synergistic Catalytic Effect of Ag and MgO Nanoparticles Supported on Defective BN Surface in CO Oxidation Reaction.

Micron-sized supports of catalytically active nanoparticles (NPs) can become a good alternative to nanocarriers if their structure is properly tuned. Here, we show that a combination of simple and easily scalable methods, such as defect engineering and polyol synthesis, makes it possible to obtain Ag and MgO nanoparticles supported on defective hexagonal BN (h-BN) support with high catalytic activity in the CO oxidation reaction. High-temperature annealing in air of Mg-containing (<0.

Translucency and Color Stability of a Simplified Shade Nanohybrid Composite after Ultrasonic Scaling and Air-Powder Polishing.

We aimed to assess the influence of professional dental prophylaxis on the translucency and color stability of a novel simplified shade nanohybrid composite material. Sixty composite disks (5 mm in diameter and 2 mm thick) of light ( = 30) and dark ( = 30) shades were prepared. The specimens were randomly divided into the following three groups ( = 10) according to the prophylaxis procedure used: ultrasonic scaling, air-powder polishing with sodium bicarbonate, and controls.

Stabilization of the (CH)NHSO High-Temperature Phase in New Silica-Based Nanocomposite Systems.

In this study, the electrotransport, thermal and structural properties of composite solid electrolytes based on (CH)NHSO plastic phase and silica (1 - x)EtNHSOxSiO, where x = 0.3-0.9) were investigated for the first time.

New Type of Nanocomposite CsHPO-UiO-66 Electrolyte with High Proton Conductivity.

New (1−x)CsH2PO4−xUiO-66 electrolytes with high proton conductivity and thermal stability at 230−250 °C were developed. The phase composition and proton conductivity of nanocomposites (x = 0−0.15) were investigated in detail.

Comprehensive Enzymatic Conversion of Starch for the Food Industry.

This study demonstrated the feasibility of comprehensive enzymatic conversion of starch for non-waste applications in food industry. Enzymatic conversion of starch gives rise to nano-sized particles that can be used for manufacturing biodegradable and edible packaging materials and glucose syrup for replacing sugar in confectionery formulations. The 96 h enzymatic hydrolysis yielded starch nanoparticles smaller than 100 nm.

Densification and Proton Conductivity of LaBaScO Electrolyte Membranes.

Bain LaBaScO impairs sintering and leads to a decrease in its ceramic density. Two approaches have been studied for obtaining dense ceramics: using a high processing temperature and the introduction of a CoO sintering additive. An addition of only 0.

Evolution of the Microstructure and Phase Composition of the Products Formed in the Reaction between Iridium and WB.

In the present study, we perform a systematic examination of the products formed by mixing and heating of tungsten boride and iridium powders at different ratios in a broad temperature range using qualitative and quantitative X-ray analysis and time-of-flight neutron diffraction (TOF-ND), in combination with scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) performed at different accelerating voltages. The well-known and unknown ternary W-Ir-B phases were detected. The Vickers microhardness value for the new ternary WIrB boride was measured.