The paper demonstrates the possibility of forming flat substrates for grazing incidence X-ray mirrors with an accuracy of RMS ∼0.7n m, and also implements a technique for manufacturing grazing incidence X-ray optical elements with cylindrical surface profiles, using ion beam etching. The technique assumes the linear movement of the workpiece behind a slit diaphragm with a speed that varies depending on the coordinate. The result of the work was the creation of a pair of X-ray mirror substrates for a Kirkpatrick-Baez collimating system, having surface shape deviations from the ideal plane of H M1=1.05µm and H M2=1.13µm, and from the calculated parabolic cylinders of R M S M1=3.0n m and R M S M2=2.9n m. The described technique makes it possible to produce substrates for mirrors in the form of elliptical and parabolic cylinders used in commercial diffractometers, synchrotrons, and free electron lasers for collimation and focusing of X-ray radiation, as well as in the telescopes of space observatories.

Ruddlesden - Popper phases are promising materials for solid oxide fuel cell/electrolyzer air electrodes, oxygen separation membranes and other electrochemical devices due to their high oxygen mobility provided by a cooperative mechanism of oxygen migration involving both regular and highly-mobile interstitial oxygen. This work aims at studying structural, surface and oxygen transport properties of Sm-doped Nd nickelates sintered in a furnace at the temperatures in the range of 800-1250 degrees C and using electron beams at the temperatures in the range of 1150-1250 degrees C. Nd2-xSmxNiO4+delta, x = 0.2 and 0.4 are synthesized by a modified Pechini technique and characterized by X-ray diffraction, X-ray photoelectron spectroscopy and temperature-programmed isotope exchange of oxygen with (CO2)-O-18 in a flow reactor. The phase composition studies show the ability to obtain single-phase materials at certain sintering conditions. Nd/Sm ratio on the surface is close to stoichiometric one, while (Nd + Sm)/Ni ratio on the surface is below stoichiometric. Such materials possess a high oxygen mobility (D* up to similar to 10(-7) cm(2)/s at 700 degrees C).

Cocrystals of betulin with dicarboxylic acids were obtained using mechanochemical treatment with the addition of small amounts of organic solvents. The formation of cocrystals was confirmed by powder X-ray diffraction, thermal analysis, and IR spectroscopy methods. The presence of a solvent, the optimal components ratio, and the duration of mechanical processing are important for the formation of cocrystals. In order to choose a solvent for preparing betulin cocrystals, the solvents of different polarity were compared. It has been shown that cocrystals are formed if solvents that can effectively dissolve dicarboxylic acid are used during mechanical processing. For comparison with the mechanochemical method, betulin cocrystals were obtained by heating a mixture of starting reagents. Morphological changes observed by scanning electron microscopy upon heating the reaction mixtures also indicate the formation of cocrystals. It has been shown that when cocrystals are dissolved in water, solutions with an increased concentration of betulin are formed, and an increase in the length of the aliphatic chain of the acid leads to a decrease in the rate of betulin release into the solution.

We consider the influence of mechanical activation and radiation-thermal sintering on the synthesis of indium lead tantalate, used in optical electronics and capacitor-based technologies, and the system(1 - & khcy; )Pb (2) YbNbO (6) + & khcy; Pb (2) FeNbO (6) (& khcy; = 0.1), the solid solutions of which exhibit high di-, piezo- and magnetoelectric characteristics. The conditions of perovskite and pyrochlore phase formation during both mechanochemical synthesis and subsequent sintering within a wide temperature range with different electron beam exposure times are investigated. To reduce the electrical conductivity of the ceramic, lithium carbonate, which is also a stabiliser of perovskite structure, was introduced into the batch. It has been shown that the characteristics of the final product are determined by the chosen conditions of batch preparation for sintering. The methods of such preparation differing in the order of mechanical activation and the conditions for introducing the components are compared. The optimal conditions have been established that make it possible to obtain piezoceramics with the largest amount of the perovskite phase and maximum density. The prospects of using radiation-thermal sintering on several piezoceramic systems were assessed. It has been established that a number of intermediate phases are formed during radiation-thermal synthesis, though these phases never appeared during conventional sintering. The results obtained in the work suggest that sintering of some lead-containing samples at an accelerator under the action of the electron beam is a promising method to synthesise a monophase complex oxide with perovskite structure. The developed method is of practical interest for obtaining piezoceramics.

The dependence of mechanical characteristics (hardness and tensile strength) of polyurethane on the content of MgFeGa layered triple hydroxide additive and the electron beam irradiation dose is investigated. The optimal amount of layered hydroxides and the optimal irradiation dose, causing a substantial increase in tensile strength and hardness of polyurethane, are determined. Polyurethane modification by adding magnesium/iron/gallium layered triple hydroxides in the amount of 3 wt% causes an increase in tensile strength and hardness by 30.0 and 5.4%, respectively. Modification of pure polyurethane by irradiation with the optimal dose (100 kGy) promotes an increase in tensile strength by 27.1% and hardness by 4.6%.

In the present work, the morphological changes of synthetic diamond microcrystals of cuboctahedral shape upon oxidative etching in oxygen or synthetic air at elevated temperatures were studied. It was found that, at the early stages, selective etching of the {111} facets occurs, resulting in the formation of triangular etch pits. Crystals etched at 600-700 degrees C up to high transformation degrees are of skeletal type: in these crystals, the {111} facets are severely etched. At temperatures above 700 degrees C, the {100} facets start demonstrating etch pits. These pits are of square shape and have a stepped morphology. Oxidative etching at 900 degrees C leads to the formation of diamond crystals of antiskeletal type at high transformation degrees (30-50 %). It is suggested that the observed change in the morphology of the diamond crystals with temperature of the oxidative etching is related to the change in the ratio of the etching rates of the {111} and {100} facets.

Synthesis and study of materials based on bismuth cerates and titanates were carried out. Complex oxides Bi1.6Y0.4Ti2O7 were synthesized by the citrate route; Bi2Ce2O7 and Bi1.6Y0.4Ce2O7—by the Pechini method. The structural characteristics of materials after conventional sintering at 500–1300 °C were studied. It is demonstrated that the formation of a pure pyrochlore phase, Bi1.6Y0.4Ti2O7, occurs after high-temperature calcination. Complex oxides Bi2Ce2O7 and Bi1.6Y0.4Ce2O7 have a pyrochlore structure formed at low temperatures. Yttrium doping of bismuth cerate lowers the formation temperature of the pyrochlore phase. As a result of calcination at high temperatures, the pyrochlore phase transforms into the CeO2-like fluorite phase enriched by bismuth oxide. The influence of radiation-thermal sintering (RTS) conditions using e-beams was studied as well. In this case, dense ceramics are formed even at sufficiently low temperatures and short processing times. The transport characteristics of the obtained materials were studied. It has been shown that bismuth cerates have high oxygen conductivity. Conclusions are drawn about the oxygen diffusion mechanism for these systems. The materials studied are promising for use as oxygen-conducting layers in composite membranes.

In this paper, we present results of a study on the possibilities of the mechanochemical synthesis of copper-substituted hydroxyapatite with the replacement of calcium cations by copper cations. During the synthesis, various reagents—sources of copper cations—were used. It was found that the nature of the carrier of the doping cation plays an important role in the formation of the structure of Cu-substituted apatite. It was established that a single-phase material forms most efficiently when copper (II) phosphate is employed; however, even this reagent did not allow the introduction of a large amount of copper into the hydroxyapatite crystal lattice. Out of 10 calcium cations in the unit cell of hydroxyapatite, no more than two could be replaced by copper cations. A further increase in the copper concentration led to the formation of an amorphous product. The degree of copper substitution in hydroxyapatite increases as the oxidation state of copper increases. The thermal stability of the hydroxyapatite with the highest degree of substitution was studied. It was shown that the presence of copper cations significantly decreases the stability of hydroxyapatite. In a temperature range of 550–750 °C, it is gradually decomposed to form a mixture of rhombohedral Ca2.57Cu0.43(PO4)2 and CuO. The FTIR spectrum of Ca2.57Cu0.43(PO4)2, which is a copper-substituted β-Ca3(PO4)2, was first studied.

Weakly conductive barium aluminate ceramics are synthesized and investigated. Firing in an oxidizing medium yields single-phase ceramics with a maximum compressive strength of 678.5 MPa and a density of 3.78 g/cm3. It is shown that conductive additives embedded into the composition raise the electrical conductivity of the ceramics to 1.05 × 10−4 S/cm (at 300°C).

В настоящей работе исследовано влияние радиационно-химической модификации энергоемких соединений с различными дозами ионизирующего излучения на характеристики термораспада, морфологию поверхности кристаллов и горения высокоэнергетических конденсированных систем (ВКС) на их основе. Объектами исследования являлись поли-N-аллилметил-5-винилтетразол (МПВТ-А), гексанитрогексаазаизовюрцитан (HNIW), октоген (НМХ) и ВКС на их основе. Образцы облучались потоком электронов на ускорителях У-12 и ИЛУ-6 (энергия электронов 2,4–3,1 МэВ; импульсный ток 100-328 мА; частота импульсов 2,5–200 Гц) дозами от 20 до 120 кГр.

Исследована зависимость механических свойств полиуретана (твердость и прочность) от содержания введенных частиц слоистого тройного гидроксида MgFeGa и дозы облучения электронным пучком. Найдено оптимальное количество слоистых гидроксидов и оптимальная доза облучения, значительно повышающие прочность при растяжении и твердость полиуретана. Модификация полиуретана путем добавления слоистых тройных гидроксидов магний/железо/галлий в количестве 3 мас. % приводит к повышению прочности при растяжении и твердости на 30.0 и 5.4 % соответственно. Модификация чистого полиуретана облучением при оптимальной дозе (100 кГр) способствует увеличению прочности при растяжении на 27.1 % и твердости на 4.6 %. The dependence of mechanical characteristics (hardness and tensile strength) of polyurethane on the content of MgFeGa layered triple hydroxide additive and the electron beam irradiation dose is investigated. The optimal amount of layered hydroxides and the optimal irradiation dose, causing a substantial increase in tensile strength and hardness of polyurethane, are determined. Polyurethane modification by adding magnesium/iron/gallium layered triple hydroxides in the amount of 3 wt% causes an increase in tensile strength and hardness by 30.0 and 5.4%, respectively. Modification of pure polyurethane by irradiation with the optimal dose (100 kGy) promotes an increase in tensile strength by 27.1% and hardness by 4.6%.

The paper presents the results of a study of syndiotactic polymethyl methacrylate with a molecular weight of 10 7 g/mol, synthesized by the method of ionic polymerization with radiation initiation. Changes in the chemical structure of the polymer material were analyzed by means of IR spectroscopy, differential thermal analysis, and gel permeation chromatography. The process of weight loss during thermal decomposition of the initial polymer can be divided into three stages: low-temperature, medium-temperature, and high-temperature ones. After exposure of the polymer even to minimum doses of ionizing radiation, there is no pronounced thermal effect of polymer melting. A scatter in the molecular sizes was found, as well as a relatively rapid decrease in the molecular weight under the action of X-rays in the dose range of up to 100 J/cm 3 . Polydispersity at low doses is approximately 3.5 times higher than that at doses on the order of 10 kJ/cm 3 . The achieved rate of latent image development was approximately five times compared with the polymer with a molecular weight of 10 6 g/mol under standard conditions. The contrast was 3.4. Microstructuring was performed by the X-ray lithography method on the VEPP-3 source with the use of synchrotron X-rays. The resulting microstructures are up to 5 µm high and about 2 µm in diameter.

A study is performed of the effect additives containing chromium, zirconium, silicocalcium, and carbon nanotubes have on the physical and mechanical properties of copper obtained by casting. The tensile strength increased to 10.5%, and Young’s modulus increased by 11.6–106.2%. The resistance to heat of samples modified with SiCa and Cu-Zr is enhanced by 1.9 and 1.5 times, respectively, while modifying samples with nanotubes reduces their resistance to heat by 1.2–1.8 times.

The aim of this research was to obtain the grafted copolymer of chitosan with acrylamide using the electron beam irradiation. Radiation dose was varied from 6 to 160 kGy. The highest yield of the product was observed at radiation dose of 12–40 kGy. Further increase in the dose caused a decrease in the product yield as well as its solubility in water. Using gel permeation chromatography, it was confirmed that unreacted chitosan remained in the product. NMR study of the water-soluble part of the product obtained under the doses of 6, 12, and 20 kGy showed that the length of the side chains of grafted acrylamide was about 2 elementary units. Investigation of chitosan solutions by means of dynamic light scattering revealed the presence of chitosan agglomerates in the solution. The possibility of obtaining dense films was demonstrated. Mechanical treatment of the copolymer in the ball mill caused an increase in the solubility of the samples obtained even at radiation doses of 80 and 160 kGy. It was determined by means of chromatographic methods that there were no products with low molecular weight in the ball-milled product, and unreacted chitosan did not undergo mechanocracking during the mechanical treatment.

Using the method of small-angle scattering of synchrotron radiation the thermal transformations of ε-form a hexaaminonitrowurtzitane crystals subjected to electron beam processing are studied. It is shown that the destruction of crystals treated with an electron beam begins significantly below the polymorphic transition point. An assumption was made about the effect of radiolysis products on the process of crystal destruction. A mechanism for the destruction of crystals is proposed.

The paper presents the results of a study of syndiotactic polymethyl methacrylate with a molecular weight of 107 g/mol, synthesized by the method of ionic polymerization with radiation initiation. Changes in the chemical structure of the polymer material were analyzed by means of IR spectroscopy, differential thermal analysis, and gel permeation chromatography. The process of weight loss during thermal decomposition of the initial polymer can be divided into three stages: low-temperature, medium-temperature, and high-temperature ones. After exposure of the polymer even to minimum doses of ionizing radiation, there is no pronounced thermal effect of polymer melting. A scatter in the molecular sizes was found, as well as a relatively rapid decrease in the molecular weight under the action of X-rays in the dose range of up to 100 J/cm3. Polydispersity at low doses is approximately 3.5 times higher than that at doses on the order of 10 kJ/cm3. The achieved rate of latent image development was approximately five times compared with the polymer with a molecular weight of 106 g/mol under standard conditions. The contrast was 3.4. Microstructuring was performed by the X-ray lithography method on the VEPP-3 source with the use of synchrotron X-rays. The resulting microstructures are up to 5 µm high and about 2 µm in diameter.

Small-angle scattering of synchrotron radiation is used to study thermal transformations of ε-form hexanitrohexaazaisowurtzitane crystals subjected to electron beam processing. It is shown the destruction of crystals treated with an electron beam begins far below the point of the polymorphic transition. A conclusion is drawn about the effect products of radiolysis have on the destruction of the crystals. A mechanism of crystal destruction is proposed.

Lanthanide tungstates and molybdates are promising materials for hydrogen separation membranes due to their high protonic conductivity. A promising approach to fabricating ceramics based on these materials is radiation thermal sintering. The current work aims at studying the effect of radiation thermal sintering on the structural morphological and transport properties of (Nd,Ln)5.5(W,Mo)O11.25–δ as promising materials for hydrogen separation membranes. The defect fluorite structure was shown to be preserved during radiation thermal sintering at 1100 °C. The presence of protons in hydrated samples was confirmed by TGA. According to four-electrode studies and the isotope exchange of oxygen with C18O2, the samples demonstrate a high proton conductivity and oxygen mobility. Residual porosity (up to 29%) observed for these samples can be dealt with during membrane preparation by adding sintering aids and/or metal alloys nanoparticles. Hence, sintering by e-beams can be applied to the manufacturing of hydrogen separation membranes based on these materials.

Betulin dipropionate is a natural compound with high cytotoxicity toward many cancer cells. The one-step synthesis directly from the birch bark without a separate betulin isolation stage was developed to obtain betulin dipropionate. Due to its composition, betulin dipropionate is a promising drug for treating a wide range of diseases. However, the poor water solubility of this compound has limited its applications. We prepared the composites of betulin dipropionate using two methods: ball milling of the mixtures of betulin dipropionate with synthetic and natural polymers, such as polyvinylpyrrolidone polyethylene glycol, fumed silica, arabinogalactan, and preparation of thin films with arabinogalactan by evaporating the aqueous solutions. These composites showed higher water solubility and improved antitumor properties against ascites carcinoma cells and human lung adenocarcinoma cells compared with the initial substance. Furthermore, the cell viability studies based on Annexin V and Propidium iodide probes confirmed the high proapoptotic effect of betulin dipropionate against cancer cells.