Abstract: In the present work, the growth specificity of Cd1−xMnxTe layers by the molecular beam epitaxy and results of experimental studies of several Cd1−xMnxTe layers grown on GaAs(100) hybrid substrates with CdTe buffers are presented. Our efforts were concentrated on creating structures with high crystallographic quality, specifically aiming to reduce the number of defects. Experimental results for the selected structures demonstrated that the Cd1−xMnxTe layers, with varying x, exhibit high crystallographic and surface morphology quality. Specifically, high-resolution X-ray diffraction measurements and their analysis revealed that the intensity distribution does not reflect the effects of mosaicity or dislocation density. The aim of the work was to characterize the Mn dopant depending on the x-value. The magnetic properties were studied as a function of manganese concentration by using electron paramagnetic resonance. By applying continuous wave electron paramagnetic resonance in the wide temperature range, we observed two groups of lines: from manganese and from so-called low field magnetic absorption.

Abstract: This study presents the development and characterization of novel polyvinylidene fluoride (PVDF)-based polymer composites for environmental remediation applications. We synthesized composites incorporating three types of fillers: Ti3C2Tx MXenes, magnetic nanoparticles (CoFe2O4 and γ-Fe2O3/Fe3O4), and their heterostructured combinations. To enhance the homogeneity of the composites, the filler particles were additionally coated with polyethylene glycol (PEG). Photocatalytic and sonocatalytic degradation of methylene blue (MB) dye was evaluated under light and ultrasonic irradiation, respectively. Experimental results demonstrated that PVDF-based nanocomposite with MXene/γ-Fe2O3/Fe3O4 heterostructures as the filler achieves a significant MB photocatalytic degradation rate of 40.3% within 60 minutes. Simultaneously, MXene/CoFe2O4-containing nanocomposite exhibits outstanding performance in sonocatalysis, achieving a reduction in MB concentration exceeding 45% over a similar treatment duration. These findings highlight the potential of PVDF-MXene-MNPs composite materials in environmental remediation technologies, emphasizing the critical role of PVDF as a primary component and a suitable host matrix in catalytic processes.

Abstract: Ethylene glycol (EG) is one of the contaminants in wastewater of airports because it is commonly used in the composition of aircraft deicing fluids during the cold season in northern regions. Ethylene glycol by itself has comparably low toxicity on mammals and aquatic life, but it can lead to substantial increase in chemical and biological oxygen demands. Contamination of water with EG facilitates the rapid growth of microbial biofilms that decreases the concentration of dissolved oxygen in water and negatively affects overall biodiversity. The development of simple method to decompose EG with a high efficiency and low operating costs is an important task. This study shows that ethylene glycol can be completely oxidized using UV-C activated hydrogen peroxide (H2O2/UV-C) with a high rate (up to 56 mg L–1 h–1) at optimum EG:H2O2 molar ratio of 1:10–1:15. Air purging the reaction solution at 1000 cm3 min–1 increases EG mineralization rate up to 2 times because simultaneous action of UV-activated H2O2 and O2 (H2O2 + O2/UV-C) leads to a synergistic effect, especially at low EG:H2O2 ratios. The kinetics and mechanism of EG degradation are discussed based on the kinetic plots of ethylene glycol and intermediate products.

Abstract: We report the results of a zinc oxide (ZnO) low-power micro sensor for sub-ppm detection of NO2 and H2S in air at 200°C. NO2 emission is predominantly produced by combustion processes of fossil fuels while coal-fired power plants are the main emitter of H2S. Fossil fuels (oil, natural gas, and coal) combined contained 74% of USA energy production in 2023. It is foreseeable that the energy industry will utilize fossil-based fuels more in the ensuing decades despite the severe climate crises. Precise NO2 and H2S sensors will contribute to reduce the detrimental effect of the hazardous emission gases in addition to the optimization of the combustion processes for higher output. Fossil fuel industry and the Solid-oxide fuel cells (SOFCs) are exceptional examples of energy conversion-production technologies that will profit from advances in H2S and NO2 sensors. Porosity and surface activity of metal oxide semiconductors (MOS) based sensors are both vital for sensing at low temperatures. Oxygen vacancies (V_O^(••)) act as surface active sites for target gases, while porosity enables target gases to come in contact with a larger MOS area for sensing. We were able to create an open porosity network throughout the ZnO microstructure and simultaneously achieve an abundance of oxygen vacancies by using a heat treatment procedure. Surface chemistry and oxygen vacancy content in ZnO were examined using XPS and AES. SEM was used to understand the morphology of the unique characteristics of distinctive grain growth during heat treatment. Electrical resistivity measurements were completed. Valance band was examined by UPS. Engineered Porosity approach allowed the entire ZnO act as an open surface together with creation of abundant oxygen vacancies (V_O^(••)). NO2 detection is challenging since both oxygen (O2) and NO2 are oxidizing gases and they coexist in combustion environments. Engineered porosity ZnO micro sensor detected sub-ppm NO2 under O2 interference affect mimicking realistic sensor operation conditions. Engineered Porosity ZnO performed better than previous literature findings for H2S and NO2 detection. The exceptionally high in sensor response attributed to the high number of oxygen vacancies (V_O^(••)) and porosity extending through the thickness of the ZnO with high degree of tortuosity. These features enhance gas adsorption and diffusion via porosity leading to high sensor response.

Abstract: The AlCoCrFeNi high entropy alloys are a novel structural material with wide application prospects. In order to investigate the influence of Al and Cr elements on the structure and properties of the alloys, AlxCr1-xCoFeNi (x=0.1, 0.2; 0.3, 0.4, 0.5) HEAs were prepared by mechanical alloying and spark plasma sintering. The microstructure and properties of the AlxCr1-xCoFeNi were analysed using XRD, SEM, EDS, electrochemical workstations, hardness measurement, friction and wear measurement, and room temperature compression measurement. The hardness and friction measurement results demonstrate that when x = 0.1, the crystal structure of Al0.1Cr0.9CoFeNi is composed of dual FCC phases and a trace of σ phase. With the increment of Al content, part of the FCC phase is transformed into BCC phase. When x=0.2~0.5, the alloy is composed of dual FCC phases, BCC phase and a trace σ phase. The Al0.5Cr0.5CoFeNi alloy exhibits the most favourable corrosion resistance, with a self-corrosion voltage of 0.202 V in a 3.5 wt.% NaCl solution. The hardness of alloy increases with the increasing of Al content. The Al0.5Cr0.5CoFeNi alloy exhibits the highest hardness value of 412.6 HV. At the initial stage of friction measurement, the wear mechanism of AlxCr1-xCoFeNi was adhesive wear. As the test time increased, oxide layers began to form on the surface of the alloy, resulting in a gradual increase in the coefficient of friction. At this stage, the wear mechanism was characterised by both adhesive and abrasive wear. Once the oxide layers and the wear processes reached dynamic equilibrium, the friction coefficient stabilised, and the wear mechanism transitioned to abrasive wear. Once the oxide layer and the wear process have reached dynamic equilibrium, the friction coefficient tends to stabilise gradually, and the wear mechanism is changed to abrasive wear. Al0.1Cr0.9CoFeNi has the smallest coefficient of friction of 0.513. Al0.5Cr0.5CoFeNi had the longest compression plateau and the greatest compression strain (59.7%) in the compression tests at room temperature.

Abstract: A new methodology on the determination of the surface properties of solid surfaces was recently proposed. Our new approach consisted in the accurate quantification of the London dispersive surface energy of materials using the two-dimensional inverse gas chromatography technique at infinite dilution. the notion of the net retention volume of adsorbed molecules The Hamieh thermal model proving the temperature effect on the surface area of organic molecules adsorbed on H--zeolite / rhodium catalysts at different rhodium percentages, was used to determine the accurate values of the London dispersive surface energy of solid surfaces at different temperatures. Whereas, the new method allowing a precise evaluation of dispersive adhesion work, dispersive surface enthalpy and entropy of adsorption of n-alkanes adsorbed on the catalysts. In this paper, the London dispersive surface energy and adhesion work of H--zeolite supported rhodium catalysts using the free energy of adsorbed molecules obtained from the two-dimensional inverse gas chromatography technique at infinite dilution. It was proved that the London dispersive surface energy depended on the temperature and the rhodium coefficient while the dispersive adhesion work of n-alkanes adsorbed on H--zeolite/rhodium catalysts was function of the temperature, rhodium percentage, and the carbon atom number of n-alkanes.

Abstract: Carbon materials such as graphene, carbon nanotubes, fullerene, graphite, nanodiamond, carbon nanocones, amorphous carbon, porous carbon among others are important components in many possible applications of these nanomaterials in medicine. We therefore want to give an overview of the synthesis of these nanomaterials and explain how they could be applied in medicine. The application of such materials has shown to be advantageous due to their high inertness towards chemical reactions, due to their high conductivity, due to their high mechanical strength and due to the diversity in which their structures can be combined. The challenge of applying these materials in real medical applications is also discussed.

Abstract: Hydrophobization could improve the moisture resistance of biopolymer materials, depending on the methods and materials used, providing benefits for packaging applications. The aim of this study was to compare the effect of increasing concentrations (0-2%) of candelilla wax (CW) and oleic acid (OA) on the microstructural and physicochemical properties, including water affinity, of glycerol-plasticized pea protein isolate (PPI) films. OA acidified the film-forming solution and increased its viscosity more effectively than CW. At the highest concentration, OA prevented cohesive film formation. OA caused less yellowing, matting, and a smaller reduction in UV/VIS light transmittance compared to CW. Both lipids in most cases slightly reduced the films' water content. Phase separation (creaming) of CW enhanced surface hydrophobicity, resulting in a greater reduction in water vapor permeability than OA (~37-63% vs. 2-18%). The addition of lipids did not reduce film solubility or water absorption, and OA even increased these parameters. Increasing lipid content decreased the mechanical strength and stretchability of the films by 28–37% and 18–43%, respectively. At higher lipid levels, these properties were similar. The control film exhibited low heat-sealing strength (0.069 N/mm), which improved by 42% and 52% with the addition of CW and OA at optimal levels.

Abstract:

Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy has become an invaluable tool for elucidating the structural, dynamic, and compositional properties of chemical compounds across various fields, from organic and inorganic chemistry to materials science. This review summarizes recent advancements in solid-state NMR techniques, including high-field NMR, magic-angle spinning (MAS), and multidimensional approaches, which have significantly enhanced spectral resolution and sensitivity. The review explores applications in studying crystalline and amorphous compounds, probing atomic-level structure, and investigating molecular dynamics critical to catalysts, polymers, pharmaceuticals, and complex hybrid materials. Additionally, it highlights the synergy between solid-state NMR and other characterization methods, such as X-ray diffraction and electron microscopy, which together provide a comprehensive understanding of material properties. Concluding with an outlook on future developments, this review underscores solid-state NMR’s growing impact on molecular and materials characterization.

Abstract:

Density functional theory (DFT) calculation and molecular dynamics (MD) simulation were performed to do an in-depth study on the inhibition mechanism of quaternary ammonium surfactant CI molecules with a different chain length in the presence of 1.0 M HCl and 500 ppm acetic acid on the Fe (110) metal surface. Results from DFT calculation showed that all surfactant CI molecules have good inhibition properties where the cationic quaternary ammonium groups (N⁺) and the alpha carbon act as a reactive centre to donate electrons to the metal surface with low band-gap energy of 1.26 eV. In the MD simulation, C12 with a 12-alkyl chain length showed the most promising CI molecules with high adsorption energy and binding energy values, low diffusion coefficient towards the corrosion particles and randomly scattered at low concentration that give better adsorption towards the Fe (110) metal surface. The finding on the effect of the alkyl chain length on the inhibition efficiency of all quaternary ammonium CI molecules based on computer modelling data and the success of an in-depth study on the theoretical understanding of quaternary ammonium surfactant CI molecules in the acidic medium corrosion system towards metal surface could be used as the future development of new surfactant CI molecules with ammonium-based functional groups.