Sorbents based on polyacrylonitrile fiber, containing ferrocyanides of transition metals and manganese oxides (CoMn-PAN and FeMn-PAN) or iron(III) hydroxide (CoFe-PAN) in their structure were obtained, as confirmed by the results of X-ray diffraction and energy-dispersive analyses. The selectivity of the obtained sorbents was investigated, along with their ability to sorb Cs, Ba (as an analog of Ra), P, and Be from various natural media, including river water and seawater with varying salinity of 18.2 and 33.8 ‰. The data show that the sorbents are universal for the recovery of artificial 137Cs and natural radionuclides from the natural environments, including complex salt composition (seawater). Researching the obtained sorbents during marine expeditions confirmed the efficiency of the obtained materials based on transition metal ferrocyanides and manganese oxides (CoMn-PAN and FeMn-PAN) for the sorption of 137Cs, 7Be, 210Pb, 210Po, 226Ra, 228Ra, and 234Th. Additionally, the sorbent based on transition metal ferrocyanides and iron(III) hydroxide (CoFe-PAN) was effective for the sorption of 137Cs, 7Be, 32P, 33P, 210Pb, 210Po, and 234Th. Based on the obtained results, methods for comprehensively determining artificial 137Cs and natural radionuclides using these sorbents were developed.

The critical need for effective uranium separation from complex aqueous solutions remains a central challenge in materials science today. Layered double hydroxides (LDHs) have emerged as promising uranium-absorbing materials. This study examines how different zinc-to-aluminum ratios (3,1, 2:1, and 1:1) affect both the structure and uranium(VI) absorption properties of Zn-Al LDHs. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), low-temperature N2 adsorption, and Zn K-edge extended X-ray adsorption fine structure (EXAFS) analyses revealed that while the crystal structure of the materials remained consistent, significant changes occurred in their porous and microstructures. EXAFS spectroscopy near the U L3-edge demonstrated that the dominant mechanism for U(VI) adsorption at pH 4.0 is inner-sphere complexation, involving negatively charged uranyl carbonate and hydroxyl complexes. Increasing the degree of Al substitution for Zn led to a logical enhancement in sorption capacity, reaching a maximum value of 47.2 mg/g at the optimal Zn/Al ratio of 2/1. Further increase in the substitution degree resulted in a shift towards a mesoporous structure, accompanied by a decrease in specific surface area and sorption capacity. Our findings demonstrate the potential of Zn-Al LDHs for U(VI) removal and provide a fundamental basis for future research aimed at developing more effective materials for the remediation of wastewater contaminated with hazardous radionuclides.

In this study, 3D Mg scaffolds were obtained by the spark plasma sintering (SPS), and a calcium phosphate coating was then obtained on the samples by the plasma electrolytic oxidation. A hybrid coating with vancomycin, zoledronic acid, and menaquinone MK-7 was formed to improve biocompatibility. The mechanical properties of the formed specimens were studied. According to XRD, XRF, SEM, EDS, and OSP studies obtained scaffolds have developed morphology and contain hydroxyapatite as well as bioactive substances. Formation of coatings improves the wettability of samples (contact angle decreases from 123.8 ± 3.1° to 26.9 ± 4.1°) and increases the surface roughness by more than 3 times. This makes them promising for use as a new generation of implantation materials. The results are important for the development of personalized implants with improved functional characteristics.

Fine-grained Al2O3-Ce:YAG composite ceramics with 0.05-0.3 at% Ce3 + doping were prepared by single reactive spark plasma sintering (SPS) and a two-step approach combining SPS and hot isostatic pressing (HIP) techniques. It was revealed that application of HIP provided additional homogenization of the Ce:YAG solid solution throughout the material volume, while changes in the recrystallization kinetics of constituent phases contributed to the stabilization of garnet/alumina grains sizes. An increase in external quantum efficiency in the series up to 72 % and 76 % was observed with saturation occurring at 0.2 at% Ce3+. The synchrotron radiation luminescence (SRL) kinetics allowed distinguishing two modes. In comparison with PL kinetics, the underestimation of decay time tau slow values is explained by the SR effect, which similarly to the thermal effect can also induces the formation of radiation defects and the ionization of Ce3+ 5d electrons. Both PL and SRL studies revealed the presence of concentration quenching effect in phosphors with 0.3 at% Ce3+. Measurements under excitation by blue laser diodes (LDs) in the reflection mode showed that 0.1-0.2 at% Ce3+-doped samples after HIP treatment exhibited the most favorable characteristics for application in high-power white laser lighting. White LDs equipped with 0.4 mm-thick Al2O3-0.2 at% Ce:YAG showed an optimum correlated color temperature of 6499-6602 K, a high luminous flux of 222-2500 lm, and luminous efficiency of 242-232 lm & sdot;W- 1 as LD power increased from 0.8 to 9.5 W & sdot;mm- 2 .

With the rapid advancement of energy storage technologies, there is a growing demand for affordable, efficient, and environmentally benign battery systems. Sodium-ion batteries (SIBs) present a promising alternative to lithium-ion systems due to sodium’s high abundance and similar electrochemical properties. Particular attention is given to developing NASICON -sodium (Na) super ionic conductor, type cathode materials, especially Na3V2(PO4)3, which exhibits high thermal and structural stability. This study focuses on the sol–gel synthesis of Na3V2(PO4)3 using citric acid and ethylene glycol, as well as investigating the effect of annealing temperature (400–1000 °C) on its structural and electrochemical properties. Phase composition, morphology, textural characteristics, and electrochemical performance were systematically analyzed. Above 700 °C, a highly crystalline NASICON phase free of secondary impurities was formed, as confirmed by X-ray diffraction (XRD). Microstructural evolution revealed a transition from a loose amorphous structure to a dense granular morphology, accompanied by changes in specific surface area and porosity. The highest surface area (67.40 m2/g) was achieved at 700 °C, while increasing the temperature to 1000 °C caused pore collapse due to sintering. X-ray photoelectron spectroscopy (XPS) confirmed the predominant presence of V3+ ions and the formation of V4+ at the highest temperature. The optimal balance of high crystallinity, uniform elemental distribution, and stable texture was achieved at 900 °C. Electrochemical testing in a Na/NVP half-cell configuration delivered an initial capacity of 70 mAh/g, which decayed to 55 mAh/g by the 100th cycle, attributed to solid-electrolyte interphase (SEI) formation and irreversible Na+ trapping. These results demonstrate that the proposed approach yields high-quality Na3V2(PO4)3 cathode materials with promising potential for sodium-ion battery applications.

The effectiveness of the application of 15 vol

Monophasic powders of the cubic modification and the nominal composition Li6.4Al0.2La3Zr2O12 (Al-LLZO) and Li6.52Al0.08La3Zr1.75Ta0.25O12 (Ta-LLZO) are synthesized. Dense ( 97–98

In this work, preceramic paper-derived porous Al2O3 ceramics were fabricated by spark plasma sintering at 1200-1400 degrees C and 10 MPa pressure. The microstructure and phase composition of the formed materials were investigated. The porosity, apparent density, bending strength and gas permeability of the obtained materials were also evaluated. The increase in sintering temperature from 1200 to 1400 degrees C results in densification and strengthening of Al2O3, but reducing its gas permeability. The bending strength was 16 and 33 MPa for the Al2O3 supports fabricated at 1300 and 1400 degrees C, respectively. Palladium membranes have been formed by chemical deposition on the obtained Al2O3 supports. The hydrogen permeability and hydrogen flux of 4.2 mu m-thick Pd membrane on Al2O3 support were 4 & sdot;10-9 mol(H2)/(m center dot s center dot Pa0.5) and 0.67 mol(H2)/(m2 center dot s), respectively.

The luminescence kinetics of $\mathbf{A l}_{2} \mathrm{O}_{3}-\mathrm{Ce}: Y A G$ composite ceramics with $0.05-0.3 \mathrm{at} \% \mathrm{Ce}^{3+}$ doping has been investigated in this paper. Using synchrotron radiation with an initial pulse duration of 1 ns and a fitting model in the form of temporal convolution of the initial pulse with the decay exponent allowed us to identify two modes in the decay process. For the fast mode a time constant is growing from $\sim 1-1.5$ up to $\sim 3 \mathrm{~ns}$ and its fraction is decreasing from $\sim 20-40 \%$ down to $\sim 13-14 \%$ while Ce concentration is increasing from 0.05 up to $0.3 \mathrm{at} \%$. Among the literature data, one can find both contradictory to the results obtained and supporting them. Comparison with studies of thermal quenching in $\mathrm{Ce}^{3+}$-doped phosphors suggests an effective equivalence between the effects of SR and elevated temperatures on luminescence kinetics. Confirmation of the hypothesis requires additional studies on the effect of dose load from SR on the parameters of luminescence kinetics.

The paper proposes an original one-stage method using spark plasma sintering technology (SPS) of manufacturing the ionizing radiation source (IRS) of closed type with a non-dispersible ceramic core based on pollucite obtained using aluminosilicate raw materials saturated (24.3 wt%) with cesium, and doped with 10-40 wt% CsCl. According to the XRD, EDX, AAS and DTA-TG data, optimal conditions for hydrothermal synthesis zeolite NaA were established, the consolidation kinetics and phase transformations into ceramic pollucite under SPS conditions were studied. The ceramics had a relative density of 99.8 % and mechanical strength up to 732 MPa, a low rate of cesium leaching 10-7 g/cm2 day and thermal resistance in air up to 1000 degrees C. It was confirmed by SEM and EDX that the destruction and deformation of pollucite ceramics in the composition with CsCl and steel at the boundary of their contact in the design of the IRS product was absent and diffusion of cesium outside the ceramics did not occur. The achieved cesium content in the ceramic core of the resulting the ionizing radiation source, which meets high quality and regulatory requirements, is 44.3 wt%. The results of the study may be promising for the manufacture of industrial products.

In the study, investigations were conducted on the uniaxial compaction of samples made from ultrafine ZrO2-3 mol% Y2O3 powder with varying concentrations of binders. Butadiene rubber solution in petrol and aqueous solutions of polyethylene glycols (PEG-400, PEG-1500 and PEG-4000) at concentrations of 6, 12 and 18 % were employed as binders. An exponential increase in the density of all obtained compacts followed a logarithmic trend, reaching 100 % as the compaction pressure increased from 50 to 400 MPa. The density of all green bodies after binder removal, as a function of pressure and initial binder concentration, can be satisfactorily described by a single equation. According to this equation, the binder fills the pores in the green body while having a minimal impact on the volumetric concentration of the solid phase (Zirconia Oxide). The utilization of the PEG-1500 solution as a binder enabled the attainment of the maximum density, which was 4 % higher than the presented averaged trend. The phase composition of the sintered samples consisted solely of tetragonal zirconia. It was determined that increasing the sintered sample density by augmenting the compaction pressure and reducing the binder concentration led to an increase in the green body density from 96.9 to 99.6 %, hardness from 1100 to 1350 HV, fracture toughness from 4.5 to 5.9 MPa*m1/2 and strength from 123 to 960 MPa. The use of powders with a binder mass fraction of 6-12 % enabled the fabrication of cups with a diameter of 5 mm, which could not be compacted at lower binder concentrations or without a binder due to cracking.

In this study, a promising method of spark plasma sintering (SPS) was investigated for the fabrication of ceramic matrices designed for the reliable immobilization of highly radioactive radionuclides 137Cs and 90Sr. The ceramic matrices were derived from a mixed composition of two aluminosilicate mineral-like phases - pollucite (Cs,Na) AlSi2O6 and gehlenite Sr2Al2SiO7. The originality of the developed approach lies in the utilization of hydrothermal synthesis for obtaining granulated precursor material. Hollow aluminosilicate microspheres (cenospheres) from coal fly ash served as the initial raw material, which were treated with alkaline solutions containing Cs+ and Sr2+ ions as simulants for the corresponding radionuclides. This method facilitated the achievement of high efficiency in cation removal from solutions exceeding 98 %. For a comprehensive examination of the composition and morphology of cenosphere-derived precursor particles, and the influence of sintering temperature on phase and structure formation of ceramic matrices under non-equilibrium conditions of spark plasma heating, various analytical techniques were employed. These included thermogravimetry/differential thermal analysis (TG/DTA), powdered X-ray diffraction analysis (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), as well as the method of low-temperature nitrogen adsorption for determining the specific surface area. The obtained ceramic samples exhibited high values of specific density (2.688-2.915 g/cm3), compressive strength (666-808 MPa), and Vickers microhardness (1.8-2.5 GPa), attesting to their high quality and stability. The results of the hydrolytic stability assessment revealed that the leaching rates of Cs+ and Sr2+ ions from the ceramics are extremely low, within the range of 10- 5-10- 6 g/cm2 & sdot;day. These values fully satisfy the requirements of GOST R 50926-96 and the international standard ISO 6961:1982 for solidified forms of high-level waste.

As a new display mode, laser display is becoming popular in the industry, and it has served our lives. In addition, a new material, perovskite quantum dots(QDs) is more capable of energizing laser displays with a narrow half-peak width, tunable emission and high color purity. Here, by incorporating perovskite CsPb(BrxI1-x)3 quantum dots into the glass, we explored the performance of large-size glass in laser display. It is demonstrated that the sheet of CsPbBr3 and CsPb(Br0.25I0.75)3 glasses has good wavelength uniformity, and the phosphor wheel with the sheets yields a wide color gamut (its color gamut reaches 124.3% of NTSC and 91.3% of Rec.2020), which will play a significant advantage in the field of laser projection.

The paper presents an original method for synthesizing high-density composite ceramics with a Mo2C/Mo3Co3C composition using the technology of high-speed Spark Plasma Sintering (SPS) of a mechanically activated powder mixture of Mo2C-10 wt%Co. The activated homogeneous starting mixture was obtained by wet milling/activation of the initial powders of Mo2C and Co in an anhydrous isopropanol medium. The ceramic samples were consolidated by SPS under vacuum (10(-5) atm.) at 1000, 1100, 1150, and 1200 degrees C with a heating rate of 87.3 degrees Cmin(-1) under constant external uniaxial pressing pressure of 50 MPa. The sintering kinetics were studied, the twofold nature of sintering was established, and the temperature range of active densification was determined. The ceramic synthesis is accompanied by a reactive interaction of the components, resulting in the formation of the Mo3Co3C phase and a change in the crystal lattice of the non-stoichiometric Mo2Cx compound. The ceramic obtained in the temperature interval of the isothermal sintering stage of 1150-1200 degrees C is homogeneous in the distribution of Mo and Co, consists of a Mo2C/Mo3Co3C phase mixture, has a density value of 98.13 +/- 0.5 % theoretical density, and has an average Vickers hardness value of similar to 1526 HV. Increasing the sintering temperature to 1200 degrees C results in the formation of almost monolithic structures in the samples, but also induces the formation of large defects due to the collective consolidation of pores within the bulk material and increases the susceptibility of the ceramic to cracking. The paper presents preliminary results from electrochemical testing. The proposed method for synthesizing Mo2C/Mo3Co3C ceramics has potential for use in optimizing the composition and production methods of electrode materials for the realization of active components in heterostructured electrodes used for hydrogen evolution.

Composite sorbents based on Fe3O4 and Zn-Al-LDH with different weight ratios of magnetic and sorbing phases were obtained by the precipitation method. The optimal weight ratio of Zn/Fe was 16, which resulted in a 62

Zeolites have become promising adsorbents for wastewater treatment due to their enhanced adsorption capacity, stability of crystalline structure, high porosity and surface area. One of the primary goals of our study was to assess the effectiveness of employing NaY zeolite as a sorbent and potential solid matrix for immobilizing radionuclides. In this study NaY faujasite zeolite was obtained by hydrothermal synthesis and characterized by X Ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) methods. The prepared zeolite had NaY faujasite crystalline structure, characterized by developed surface area (370 m2/g) with micro-mesoporous structure, and spherical-like morphology with particles of 1-4 mu m in diameter. The isotherms adsorption modeling on Cs+, Sr2+, Co2+, Pb2+ and La3+ ions was performed. The isotherm well described by Langmuir equation with maximum adsorption capacity of q(Cs+) = 1,9 mmol/g, q(Sr2+) = 3,75 mmol/g, q(Co2+) = 1,82 mmol/g, q(Pb2+) = 2,54 mmol/g, q(La3+) = 3,83 mmol/g. Thermal behavior of metal-saturated adsorbents by differential thermal analysis (DTA) and thermal gravimetric (TG) techniques was studied. Each metal examined in this paper is responsible for the stable formation of radionuclides (137Cs, 90Sr, 60Co, La generally, the group of active lanthanides was modelled, Pb uranium fission residues) that are generated during the operation of nuclear power plants. To optimize sintering regimes, it has been proposed to achieve sorption saturation of stable ions such as Cs, Sr, Co, La, and Pb and transfer them into solid matrices. It was shown that the consolidation temperature for the obtained samples varies in the range of 935-1040 degrees C.

The dispersed Ca3La6(SiO4)6 biocomposite was obtained by treating a calcium silicate sol containing 0.1, 0.3, and 0.7 mol of La3+ under hydrothermal conditions. The composition, morphology, and structure of the biocomposite were studied by powder X-ray diffraction, SEM, and EDS methods. The reaction products (CaSiO3, CaLa4(SiO4)3O, Ca3La6(SiO4)6) depending on the La3+ concentration were determined. The structural characteristics of biocomposite powders with different La3+ contents were investigated by BET and DFT methods. The sorption characteristics of the materials towards 5-fluorouracil were studied depending on pH. The highest sorption capacity (0.768 mg/g at pH 3) was found for the Ca3La6(SiO4)6 sample containing 0.3 mol of La3+. Additionally, the biocompatible properties of biocomposite samples in contact with artificial blood plasma were evaluated by establishing the key changes in their composition, morphology, and structure upon the formation of the apatite bioactive phase on the accessible surface of the samples. These results hold promise for further development of new sorption materials, including biomaterials, for targeted drug delivery with a potential for practical application.

The use of ceramics as matrices for immobilization of radionuclides for the purpose of their safe long-term disposal or useful application is studied with an emphasis placed on phase stability, structural integrity, hydrolytic stability, etc. This work implements a combined approach based on the sol–gel citrate synthesis of nanosized La2Ti2O7 powder and its subsequent spark plasma sintering to produce dense ceramics. The phase composition and structure of the nanosized La2Ti2O7 powder and the ceramic samples obtained in the temperature range of 900–1300°C were studied by powder X-ray diffraction and SEM. It was shown that the conditions of synthesis of the powder ensure the formation of nanosized crystalline La2Ti2O7 grains, consolidation of which under spark plasma heating is accompanied by a change in the phase composition of La2Ti2O7 from a single-phase monoclinic structure to orthorhombic structure with a LaTiO3 impurity at temperatures above 1200°C. It was found that a change in the ceramic structure is accompanied by the formation of non-porous and defect-free monolithic samples. This type of change was shown to lead to an increase in the relative density (81.3–95.7

This study presents the fabrication possibilities of ultra-high-temperature ceramics of ZrB2-30 vol.%SiC and (ZrB2-HfB2)-30 vol.% SiC composition using the reaction spark plasma sintering of composite powders ZrB2(HfB2)-(SiO2-C) under two-stage heating conditions. The phase composition and microstructure of the obtained ceramic materials have been subjected to detailed analysis, their electrical conductivity has been evaluated using the four-contact method, and the electron work function has been determined using Kelvin probe force microscopy. The thermal analysis in the air, as well as the calcination of the samples at temperatures of 800, 1000, and 1200 °C in the air, demonstrated a comparable behavior of the materials in general. However, based on the XRD data and mapping of the distribution of elements on the oxidized surface (EDX), a slightly higher oxidation resistance of the ceramics (ZrB2-HfB2)-30 vol.% SiC was observed. The I-V curves of the sample surfaces recorded with atomic force microscopy demonstrated that following oxidation in the air at 1200 °C, the surfaces of the materials exhibited a marked reduction in current conductivity due to the formation of a dielectric layer. However, data obtained from Kelvin probe force microscopy indicated that (ZrB2-HfB2)-30 vol.% SiC ceramics also demonstrated enhanced resistance to oxidation.

This work presents an innovative approach for creating ceramic materials based on andesite-basalts for construction on the Moon. Employing the concept of in-situ resource utilization (ISRU), the authors simulated the composition of lunar regolith using volcanic rocks from Kamchatka and Primorsky Krai (Russia, Far East). These rocks were ground into submicron powders and sintered via spark plasma sintering (SPS) at temperatures of 800, 900, and 1000 degrees C. The resulting ceramic samples demonstrate exceptional physicomechanical properties comparable to lunar regolith - compressive strength up to 566 MPa and Vickers hardness up to 650 HV. Optimal characteristics were achieved at a sintering temperature of 1000 degrees C with a heating rate of 300 degrees C/min. It was determined that the heating rate during sintering has a decisive influence on the density of the resulting ceramics. This research vividly demonstrates the potential of SPS technology and the ISRU concept for creating highstrength construction materials on the Moon using local lunar raw materials, paving the way for large-scale construction of lunar bases utilizing the Moon's own mineral resources.