Hafnium hydride is studied as an absorber for fast neutron reactors. A high value of the neutron absorption cross section is noted that is retained by all hafnium isotopes formed during neutron irradiation in reactor. However, there is a risk of hafnium hydride decomposing in the range of 600–700°C, which corresponds to the operating temperature of absorbers in fast neutron reactors. An approach is proposed to reduce hydrogen evolution from hafnium hydride that consists of applying a protective hafnium oxide coating to it. Hafnium hydride samples are annealed in helium at temperatures of 1200°C in a synchronic thermal analysis setup. Hydrogen desorption starts at a temperature of 640°C. Complete hydrogen evolution is observed at a temperature of 1200°C. A substantial drop in hydrogen evolution at low temperatures is seen when annealing samples with applied coatings. A special setup is developed that allows the thermal testing of hydride materials in a liquid sodium environment. Hafnium hydride is annealed in liquid sodium at 700°C. Synchronic thermal analysis of samples after exposure to sodium reveals a drop in the emission of gas that is associated with an increase in the thickness of the oxide layers on the surfaces of samples.

It has been shown that associates of cationic glycerolipid (CGL), rac-N-4-[(2-ethoxy-3-octadecyloxyprop-1-yl)oxycarbonyl]butyl-N'-methylimidazolium iodide, which has a pronounced antitumor effect, can be used for the solubilization of two hydrophobic biologically active compounds (curcumin and capsaicin) and as templates in the sol–gel synthesis of silica mesoporous container particles (MCPs). The thermodynamic characteristics of solubilization are determined, and it is shown that this process contributes to a significant increase in the solubility of both hydrophobic drugs in water. The hydrolytic condensation of tetraethoxysilane in the presence of CGL associates containing curcumin or capsaicin leads to the formation of MCPs characterized by a narrow size distribution and a high content of encapsulated drugs. This combination of the stages of the synthesis and loading of MCPs is of undoubted interest in relation to the nanoencapsulation of cationic glycerolipids (including in combination with other drugs).

A new method for encapsulating cationic glycerolipids is proposed, based on their use as templating agents in the sol-gel synthesis of mesoporous silica particles. Using the example of rac-N-{4-[(2-ethoxy-3-octadecyloxyprop-1-yl)oxycarbonyl]butyl}-N'-methylimidazolium iodide, it is shown that this method results in the formation of highcapacity container particles with a pronounced porous structure and a narrow size distribution.

The creation of antibacterial nanocomposites that provide prolonged release of encapsulated drugs is of great interest for various fields of medicine (dentistry, tissue regeneration, etc.). This article demonstrates the possibility of creating such nanocomposites based on sodium alginate and drug-templated mesoporous silica nanocontainers (MSNs) loaded with two bioactive substances. Herein, we thoroughly study all stages of the process, starting with the synthesis of MSNs using antiseptic micelles containing the hydrophobic drug quercetin and ending with assessing the activity of the resulting composites against various microorganisms. The main emphasis is on studying the quercetin solubilization in antiseptic micelles as well as establishing the relationship between the conditions of MSN synthesis and micelle morphology and capacity. The effect of medium pH on the release rate of encapsulated drugs is also evaluated. It was shown that the MSNs contained large amounts of encapsulated drugs and that the rate of drug unloading depended on the medium pH. The incorporation of such MSNs into the alginate matrix allowed for a prolonged release of the drugs.

This paper is the first part of a three-part review that looks at the effect of doping elements on the behaviour of helium, the development of gas porosity, as well as at the amount of retained hydrogen introduced into vanadium alloys with Ti, Cr, W and Ta (using different techniques) with a rapid decay of induced radioactivity. The same regularities have been identified regarding how the chemical composition of the alloys impacts the hydrogen entrapment and retention regardless of the way it is introduced: either through pressure saturation without defect formation or through ion implantation with radiation-induced defects entailed. It was established that when vanadium is doped with a chemically active element (V – Ti alloys), the concentration of the latter has a nonmonotonic effect on the helium porosity and the mass fraction of retained hydrogen. It can be attributed to the way titanium interacts with oxygen and nitrogen in vanadium, which dictates how much titanium hydride will form. The paper demonstrates that pre-irradiation of the alloy with helium ions results in a higher amount of retained hydrogen when it is introduced further, regardless of the temperature.

Specific features of the seedless synthesis of gold nanoparticles in micellar solutions of both individual alkyltrimethylammonium bromides with different hydrocarbon chain lengths and their mixtures have been studied. The main attention has been focused on studying the possibility of controlling the shape and, consequently, the position of the localized surface plasmon resonance of the nanoparticles in the presence of octadecyltrimethylammonium bromide (OTAB). It has been found that its use leads to the formation of monodisperse gold nanorods with a larger aspect ratio than that in the case of cetyltrimethylammonium bromide, which is commonly used for this purpose. Moreover, it has been shown that the introduction of OTAB into micellar solutions of its homolog with a noticeably shorter alkyl chain (dodecyltrimethylammonium bromide) promotes a change in the shape of the formed gold nanoparticles from spherical to rodlike one.

The work presents the results of chemical composition and surface structure changes of 0.12%C-18%Cr-10% Ni-0.5%Ti austenitic steel irradiated by 98 MeV Fe-56(10+) ions at 923 K up to 7.05.10(20) ions/m(2). Irradiation was carried out in the accelerator DC-60 in the branch of Nuclear Physics Institute of Kazakhstan Republic (Nur-Sultan city). Structural studies were carried out using a JEOL JSM7500F scanning electron microscope with an attachment for elemental analysis and an AIST-NT SmartSM-1000 atomic force microscope. It was shown that ion irradiation causes grain etching. Complex columnar structure is formed on the grains surfaces which is mainly consists of chromium oxide. Ion irradiation causes a radiation-induced redistribution of the elements on the sample surface also: grain boundaries are enriched by iron and nickel and depleted in chromium. In addition, it was found that particles of the second phases (carbide or carbonitride of titanium) dissolve under irradiation.

The regularities and features of dynamic deformation aging of Armco iron samples uniformly in volume implanted with helium to a concentration of ~10 –3 at % He under irradiation with α particles with an energy of 50 MeV were studied. Unirradiated and irradiated samples were deformed by tension at a rate of 8.3 × 10 –4 s –1 at temperatures of 295–475 K, and the mechanical properties and energy characteristics—strain work, dissipated heat, and total stored energy—were determined. It was shown that, under tension in the temperature range of 350–600 K in the unirradiated and in the irradiated material, the process of dynamic deformation aging occurred. The effect of increase in the ductility of iron implanted with helium in the temperature range of 425–475 K, accompanied by additional heat release, was discovered. The increase in the plasticity of iron implanted with helium is explained by the formation of complex clusters containing helium atoms, vacancies, and impurity atoms, which leads to the clearing of the matrix of interstitial atoms and facilitating the movement of dislocations.

The microstructure and mechanical properties of 18Cr10NiTi austenitic steel were studied after high-temperature neutron irradiation of samples in a helium atmosphere. It was revealed during irradiation, helium penetrates into steel samples forming bubbles distributed on dislocations and along grain boundaries. Character of the temperature dependence of the mechanical characteristics of irradiated steel indicates a high-temperature radiation embrittlement of steel. The character of the mechanical properties temperature dependence change of irradiated steel points to its high-temperature radiation embrittlement.

The results of experiments on cyclic thermal shock tests of promising neutronabsorbing titanium boride coatings are presented. It has been established that the main effect is the high-temperature oxidation of titanium boride with the formation of titanium and boron oxides. The regularities of changes in the oxidation parameters during cyclic thermal shock tests are determined.

The work presents the calculated mean free paths of hydrogen, deuterium and helium ions in boron-carbon and boron-titanium films of various configurations. Has been rated impact of these coatings at various film thicknesses for ion capture in tungsten. The calculations were carried out using the software package SRIM-2012, for each mileage value was calculated by modeling of10,000 cascades.

Vanadium alloys are considered candidates for use as structural materials of fusion reactors. A large amount of helium will be accumulated in such materials. The presence of helium in the materials may result in gas swelling. This paper presents the results on helium porosity formation researches in V–Ti–Cr, V–W–Zr and V–W–Ta alloys obtained by means of TEM. Samples were irradiated by 40 keV Не + ions up to dose of 5∙10 20 m -2 at 923 K. Alloy V–4%Ti–4%Cr has a smallest helium swelling among the ternary alloys and its swelling is significantly lower than swelling of dual V–Ti and V–Cr alloys. The swelling of the ternary V–2%W–1%Zr alloy is more than 3 times less than the swelling of vanadium, several times less than that of V–W alloys and slightly lower than the swelling of V–Zr alloys. Swelling increases by a factor of 1.5 with increasing of Zr content to 2% in the ternary V–2%W–1%Zr alloy. Similarly, gas swelling of ternary V–2%W–1%Ta alloy is significantly lower than that for binary V–W and V–Ta alloys. Assumptions are made about the possible mechanisms of the effect of alloying elements in vanadium on helium porosity formation.

Oxide dispersion strengthened (ODS) ferritic-martensitic steels are considered as promising structural materials for fusion reactors, as well as for active zone of new generations fast reactors. In this connection, peculiarities of helium porosity formation and gaseous swelling have been investigated in the dispersion-strengthened EP-450 ODS steel with 0.3 and 1 wt.% Y2O3 dispersant produced by spark plasma sintering (SPS) as compared with the matrix EP-450 steel, EP-450 ODS steel produced using a hot extrusion (HE) as well as reactor austenitic ChS-68 steel. The samples were irradiated by 40-keV He+ ions at 923 K up to fluence of 5 x 10(20) ion/m(2). Microstructural investigations of irradiated samples were performed using a transmission electron microscope. It is found that plurality of zones with a very different type of helium porosity and different character of their distribution is developed in steel with 1 wt.% Y2O3. Such zones are less in steel with 0.3 wt.% Y2O3 as opposed to matrix EP-450 steel, EP-450 ODS steel obtained by HE, and austenitic ChS-68 reactor steel. It is found in comparing the character of helium porosity formation in the matrix steel EP-450, steel EP-450 ODS (HE) and EP-450 ODS (SPS) that bubbles are developed with a smaller average sizes and, therefore, helium swelling is lower in all ODS steels than that in steel EP-450, but for ODS steel made by SPS, swelling is significantly higher than in ODS steel produced by hot extrusion. At the same time, austenitic steel ChS-68 shows a minimum gaseous swelling for the used conditions of helium ion irradiation. An assumption is made that the extremely non-uniform distribution of helium bubbles (gas filled pores) both in volume and size in SPS steel is associated with the initially highly defect structure, including the residual porosity in 1-3% as well as a result of strong redistribution of chromium between ferritic grains and grains of tempered martensite during manufacturing of samples.

The review concerns some problems of hydrogen in the main reactor structural materials used in the core of nuclear reactors. Zirconium alloys, steels, and vanadium alloys, as well as the hydrogen and helium synergetic effect exerted on the radiation resistance, are considered. The main sources resulting in the accumulation of hydrogen isotopes in reactor materials are discussed. The causes and consequences of hydride embrittlement of zirconium alloys at relatively low temperatures are analyzed. It is shown that hydrogen can induce the embrittlement of vessel steels through the weakening interatomic bond forces and a stabilization of radiation-induced defects. It is demonstrated that hydrogen in the presence of helium behaves like a gas that enhances the irradiation effect on the microstructure and properties of materials in many cases. The irradiation with simultaneous introduction of hydrogen and helium causes, in particular, a catastrophic swelling of chromium steels and vanadium alloys, whereas in the case of austenitic steel the effect is less pronounced.

The paper presents the results of studies of physical and mechanical properties, helium and hydrogen behavior in vanadium-titanium alloys depending on titanium content. In particular, the results of helium swelling research, thermal desorption studies of helium and hydrogen behavior, results of internal friction measurements, measuring amount of hydrogen retained introduced by various methods. It was shown that the addition of titanium to vanadium have nonmonotonic influence on the behavior of implanted helium and hydrogen, as well as on the physical and mechanical and radiation properties known in literature. It is expected that such an abnormal influence of titanium on various properties of vanadium-titanium alloys occurs because of the interaction of vanadium and titanium atoms with atoms of interstitial impurities.

Transmission electron microscopy (TEM) has been used to study the effect of the initial structural-phase state (SPhS) of ferritic-martensitic steels EK-181, EP-450 and EP-450-ODS (with 0.5 wt.% nanoparticles of Y2O3) on the of helium porosity formation and gas swelling. Different SPhS of steel EK-181 was produced by water quenching, annealing, normalizing plus tempered, intensive plastic deformation by torsion (HPDT). Irradiation was carried out by He+-40 keV ions at 923 K up to fluence of 5.10(20) He+/m(2). It is shown that the water quenching causes the formation of uniformly distributed small bubbles ((d) over bar similar to 2 nm) of the highest density (rho similar to 10(25) m(-3)). After normalization followed by tempering as well as after annealing bubbles distribution is highly non-uniform both by volume and in size. Very large faceted bubbles (pre-equilibrium gas-filled voids) are formed in ferrite grains resulting in high level of gas swelling of the irradiated layer with S = 4,9 +/- 1,2 and 3.8 +/- 0.9 % respectively. Nano- and microcrystalline structure created by HPDT completely degenerate at irradiation temperature and ion irradiation formed bubbles of the same parameters as in the annealed steel. Bubbles formed in EP-450-ODS steel are smaller in size and density, which led to a decrease of helium swelling by 4 times (S = 0.8 +/- 0.2 %) as compared to the swelling of the matrix steel EP-450 (S = 3.1 +/- 0.7 %).

The results of structure investigation, distribution uniformity of dispersed particles of Y2O3, porosity and density of the ferritic/martensitic reactor steel EP-450 (0.12C–13Cr–2Mo–Nb–V–B, wt%) produced by spark-plasma sintering (SPS) are presented. More than 140 samples were produced using different combinations of mechanical alloying (time, speed of attritor rotation) and SPS parameters (temperature, speed of reaching preset temperature, pressure and time of exposure under pressure, concentration of strengthening particles). It is determined that the absence of strengthening Y2O3 nano-particles in local volumes of sintered specimens is connected with the imperfection of mechanical alloying, namely, the formation of agglomerates of matrix steel powder containing no oxide nano-particles. It has been determined that the time of mechanical alloying should not exceed 30h to provide minimum powder agglomeration, uniform distribution of Y2O3 particles in the powder mixture and minimum porosity of sintered samples. Spark-plasma sintering should be performed at the lowest possible temperature. As a result it was found that samples with 99% theoretical density can be obtained using the following optimized SPS-parameters: sintering temperature is 1098÷1163K; speed for reaching the preset temperature is >573K/min; load is 70÷80MPa; time of exposure under pressure – either without isothermal exposure, or exposure during ≥3min; optimum quantity of Y2O3 is 0.2÷0.5wt%.

The influence of alloying of vanadium by Ti and Fe on helium bubble formation, gaseous swelling and helium release peculiarities is investigated by means of transmission electron microscopy and helium thermal desorption spectrometry (HTDS). The samples were irradiated by 40keV He+ ions up to a fluence of 5⋅1020m−2 at 293 and 923K. It is found that large faceted pores/bubbles are formed in pure vanadium and it has the highest gaseous swelling. Alloying by any used quantity of Ti (from 0.1 up to 10wt.%) or Fe (from 1 up to 10wt.%) essentially decreases the helium swelling. The effect of alloying of vanadium by Ti on the bubble sizes and the helium swelling is nonmonotonic. The density of bubbles increases significantly and their sizes and swelling grow monotonically with increasing the Fe content in vanadium. With low-temperature helium implantation, alloying of V by Ti shifts the HTDS peaks to higher temperatures and the temperatures of peaks are decreased with increasing the Fe concentration. A significant portion of the helium releases in a high-temperature area beyond the main peak temperatures in the HTDS spectra. It is assumed that this is caused by formation of helium bubbles on the surfaces of incoherent particles of secondary phases (oxides, nitrides), having high binding energies with these particles.