A large body of experimental studies of swift heavy ion latent tracks in dielectric materials has produced a wide range of estimates of track size. We investigate the physical meaning of these estimates by examining the different criteria of track boundary probed by various experimental techniques, including SAXS, XRD, chemical etching and conductometry. We show that different methods probe different physical aspects of ion induced modification, such as electron density redistribution, molecular ordering, chemical reactivity and charge separation, resulting in different determinations of effective track boundaries. Particular attention is paid to polymer films with electret-like properties, where post irradiation redistribution of weakly bound electrons may play an important role in the evolution of latent track structure.

Track-etched membranes (TMs), characterized by their precisely controlled pore size, geometry, and distribution, offer a promising platform for the development of advanced membrane systems and serve as model membranes for testing and optimizing surface modification techniques. This study presents a perspective modification of poly(ethylene terephthalate) track-etched membranes (PET TM) based on photo-induced graft polymerization of allylamine (AlAm) to introduce primary amine groups on the membrane surface. The polymerization process was optimized by evaluating key parameters, including reaction time, monomer concentration, solvent, and distance from UV-lamp. Optimal conditions for photoinduced graft polymerization were found: grafting time 60 minutes, AlAm monomer concentration 50 %, 2-propanol as a solvent and distance to UV lamp 10 cm. These parameters allowed effective modification of the polymer while maintaining the integrity of the membrane porous structure. The modified membranes were characterized using SEM-EDX, ATR FTIR, and UV-spectroscopy. The results demonstrate the successful fabrication of membranes with a high amino group content (up to 10.6 +/- 0.3 mu mol/g) while preserving their porous structure. This functionalization enhances the practical potential for the environment and biomedical fields.

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1134/S1063774524060038

Cobalt nanotubes have been synthesized by electrochemical deposition in pores of ion track membranes. The structures obtained have been studied by scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis, and gas permeability method. The influence of electron irradiation on the cobalt nanotube structure has been investigated. It is shown that an increase in the irradiation dose leads to the transformation of the sample crystal structure. This fact can be explained by the simultaneous reduction of the β-Co metastable phase and relaxation of the microstress formed by the fcc phase in the lattice. The degree of sample texturing along the [100] direction increases under electron irradiation. The dependences of the resistive and magnetic properties of cobalt nanotubes on the irradiation dose have been analyzed.

The aim of this study is to determine the effect of changing the ratio of components in the composition of twocomponent xLi2TiO3 - (1-x)Li2ZrO3 ceramics on structural distortions and degradation of strength and thermal parameters under high-dose neutron irradiation. The assessment of structural changes was carried out using the electron paramagnetic resonance (EPR) method, which is one of the most accurate methods that allows for a quantitative and qualitative assessment of structural changes caused by irradiation, as well as determining the concentrations of various types of defects depending on the irradiation fluence. It was found that in the case of two-component lithium-containing ceramics, the resistance to accumulation of radiolysis products is due to the effects of the presence of interphase boundaries that inhibit the formation of radiolysis products. According to the qualitative assessment of the EPR spectra, it was established that in the case of two-component ceramics, the formation of HC2 - centers occurs at higher irradiation fluences (above 5 x 1020 neutron/cm2), while for onecomponent ceramics, the formation of radiolysis products is observed at irradiation fluences above 1019 neutron/cm2. In this case, a comparative analysis of the concentrations of defects formed in the damaged layer and their evolution indicates an increase in resistance to defect formation processes due to a change in the ratio of components in the composition of two-component ceramics. The improved stability of two-component ceramics against disordering and defect accumulation is attributed to grain boundaries, which act as barriers to oxygen vacancy migration and defect clustering.

In this study, ZrO2 nanoparticles were synthesized by the hydrothermal method using different precursors and mineralizers. X-ray diffraction revealed that the choice of synthesis components has a significant impact on the phase composition and crystallinity of the resulting ZrO2 nanoparticles. Raman spectroscopy indicated that varying the combinations of precursors and mineralizers enables the formation of both cubic and tetragonal phases of ZrO2 within the samples. Transmission electron microscopy showed that the particle size ranges from 4 to 14 nm, with crystalline samples predominantly containing particles in the 5-6 nm range. In amorphous samples, nuclei with sizes between 5 and 10 nm were observed. TGA analysis demonstrated that all samples contain a substantial amount of synthesis by-products, reaching up to 30% of the total mass. Spectroscopic analysis of the optical properties determined that samples with more than 9% by-product content exhibit the highest absorption in the UV subrange. The phase stability of ZrO2 nanoparticles and the effect of temperature on the crystallization of amorphous samples were estimated using high-temperature X-ray diffraction.

The manufacture of products from refractory ceramics requires high temperatures due to the high activation energies of the sintering process of refractory oxides. Processing temperatures for ceramics made of ZrO2, Al2O3, MgO can be reduced if a flux or glass-forming component is selected. Furthermore, in multicomponent ceramics it is possible to create more favorable thermoresistive properties. This study examines the synthesis, structural, phase and mechanical properties of multicomponent porous ZrO2-WO3-Al2O3-MgO ceramics with varying weight concentrations of components. Experimental samples were obtained by standard solid state reaction method. The analysis of fabricated samples was carried out using X-ray phase analysis, scanning electron microscopy and the Vickers microhardness test. In this work, a new approach to increasing the microhardness of porous refractory ceramics is presented, in which WO3-based flux forms a matrix composed of glass-like formations that "attach" particles of ZrO2 and MgAl2O4 phases. The obtained ceramics demonstrates high microhardness values HV0.05 for porous materials ranging from 500 to 600. Studies have shown that the selected composition of multicomponent ceramics (x = 0.10-0.25) can be used as a refractory material up to temperatures of similar to 1300 degrees C. The fabricated refractory ceramics potentially possess chemical stability and optimal microhardness properties, which makes these materials promising as a heat insulating lining in the metals, ceramics and glass manufacturing, as well as for components in the chemical industry.

The article presents the results of experimental studies of the effect of the stabilizing MgO dopant using the electron spin resonance (ESP) method on enhancement of the stability of Li2ZrO3 ceramics to defect formation processes and accumulation of radiolysis products in the near-surface layer in the case of high-dose irradiation with protons simulating the hydrogenation effects characteristic of processes associated with tritium production. During the conducted studies, it was established that the addition of the stabilizing MgO dopant results in formation of inclusions in the form of the tetragonal MgLi2ZrO4 phase, which leads to an increase in the resistance of the near-surface layers to destructive damage due to the accumulation of structural damage (oxygen vacancies and point defects), as well as products of the physicochemical processes of radiolysis, characteristic of high irradiation fluence values. It was found that in the case of unmodified Li2ZrO3 ceramics, the formation of HC2 – centers is observed at a fluence of 1016 proton/cm2, while for two-phase ceramics, the formation of HC2 – centers is observed at higher fluences, while the intensity of the bands is significantly less than in the case of single-phase unmodified ceramics. The difference in the nature of changes in the intensities of singlet bands responsible for the presence of vacancy defects in the damaged layer, as well as HC2 – centers for single-phase and two-phase ceramics is a direct confirmation of the inhibition of structural degradation mechanisms in two-phase ceramics.

Results of targeted modification of the structure and properties of ordered arrays of zinc nanotubes (Zn NTs) by accelerated Xe+22 heavy ions with a fluence of 1 × 109 to 5 × 1011 cm–2 in the energy range of 1.0–1.75 MeV/nucleon are reported. Dynamics of changes in the crystallite shape and orientation of Zn NTs before and after irradiation has been studied by X-ray diffraction. It has been shown that irradiation with accelerated ions has a significant effect on the texture coefficients of Zn NTs. In addition, at a fluence of 1 × 1011 m–2 or higher, the formation of loose areas in the structure of Zn NTs as a result of partial degradation of the crystal structure and, consequently, a decline in conductivity are observed.

This work studied the effect of sequential irradiation by krypton and helium ions at room temperature on the composition and structure of CoCrFeNi and CoCrFeMnNi high-entropy alloys (HEAs). Irradiation of the HEAs by 280 keV Kr14+ ions up to a fluence of 5 × 1015 cm–2 and 40 keV He2+ ions up to a fluence of 2 × 1017 cm–2 did not alter their elemental distribution and constituent phases. Blisters formed on the nickel surface after sequential irradiation, where large blisters had an average diameter of 3.8 μm. The lattice parameter of the (Co, Cr, Fe and Ni) and (Co, Cr, Fe, Mn and Ni) solid solutions increased by 0.17% and 0.37% after sequential irradiation, respectively. Irradiation by Kr ions led to a decrease in tensile macrostresses in the HEAs in the region of krypton ion implantation (Region I) and the formation of compressive macrostresses in the region behind the peak of implanted krypton (Region II). Sequential irradiation formed large compressive stresses in Ni and HEAs equal to −131.5 MPa, −300 MPa and −613.5 MPa in Ni, CoCrFeNi and CoCrFeMnNi, respectively, in the Region II. Irradiation by krypton ions decreased the dislocation density by 1.6–2.3 times, and irradiation with helium ions increased it by 11–15 times relative to unirradiated samples for CoCrFeNi and CoCrFeMnNi, respectively. Sequentially irradiated CoCrFeMnNi HEA had higher macrostresses and dislocation density than CoCrFeNi.

As a result of anthropogenic activities, the environment is polluted by heavy metals. The most important task is to find methods to control their content in water. Track-etched membranes (TeMs) can be relatively easily modified by nanometer layers of functional materials with using the Langmuir‒Blodgett technique, which makes it possible to specifically change the structural, selective properties of the membrane surface and obtain new materials with desired properties. The aim of the work was to develop flexible sensors for the analysis of lead ions in water based on poly(ethylene terephthalate) (PET) TeMs with perfluorodecanoic acid (PFDA) nanolayers. Techniques for modifying TeMs based on PET with a monolayer coating based on PFDA by the Langmuir‒Blodgett method, and with two-layer coatings, formed by soaking PET TeMs/PFDA in xylenol orange solutions have been developed. The microstructure and local mechanical properties of the sensor surface were studied by atomic force microscopy, and the wettability and values of the specific surface energy of PET TeMs before and after modification were evaluated using the ''sessile'' drop method. Based on the measurement of electrochemical characteristics, it was found that PET TeMs/PFDA have a higher response of electrochemical characteristics compared to PET TeMs and PET TeMs/PFDA/XO. The limit of detection for lead ions in aqueous solutions at pH = 12 was of 0.652 µg/l within 5 measurements.

High-entropy alloys (HEA) are promising structural materials that will successfully resist high-temperature irradiation with helium ions and radiation-induced swelling in new generations of nuclear reactors. In this paper, changes in the elemental and phase composition, surface morphology, and structure of CoCrFeNi and CoCrFeMnNi HEAs irradiated with He2+ ions at a temperature of 700 °C were studied. Structural studies were mainly conducted using the X-ray diffraction method. The formation of a porous surface structure with many microchannels (open blisters) was observed. The average diameter of the blisters in CoCrFeMnNi is around 1.3 times smaller than in CoCrFeNi. It was shown that HEAs’ elemental and phase compositions are stable under high-temperature irradiation. It was revealed that, in the region of the peak of implanted helium, high-temperature irradiation leads to the growth of tensile macrostresses in CoCrFeNi by 3.6 times and the formation of compressive macrostresses (−143 MPa) in CoCrFeMnNi; microstresses in the HEAs increase by 2.4 times; and the dislocation density value increases by 4.3 and 7.5 times for CoCrFeNi and CoCrFeMnNi, respectively. The formation of compressive macrostresses and a higher value of dislocation density indicate that the CoCrFeMnNi HEA tends to have greater radiation resistance compared to CoCrFeNi.

In the original publication [...].

Oxide nanoparticles exhibit unique features such as high surface area, enhanced catalytic activity, and tunable optical and electrical properties, making them valuable to various industry applications as well as for the development of new research projects. Nowadays, ZrO2 nanoparticles are widely used as catalysts and precursors in ceramic technology. Hydrothermal synthesis with metal salts is one of the most common methods for producing stable tetragonal-phase zirconium dioxide nanoparticles. However, hydrothermal synthesis requires relatively high process temperatures (160-200 degrees C) and the use of advanced heat-resistant autoclaves capable of maintaining high pressure. This paper investigates how different precursors (ZrOCl28H(2)O and ZrO(NO3)(2)2H(2)O) and synthesis temperatures (110-160 degrees C) affect the phase composition, optical properties, size, and shape of ZrO2 nanoparticles produced by hydrothermal synthesis without calcination. In addition, the effect of temperature exposure in the range of 100-1000 degrees C on the phase stability of the synthesized nanoparticles was studied. X-ray diffraction and Raman spectroscopy techniques were used to determine the structure and phase composition, while the optical properties were examined through the analysis of transmission and absorption spectra in the visible and UV ranges. It was found that the obtained particles at synthesis temperatures of 110-130 degrees C have predominantly cubic c-ZrO2 phase, which changes to monoclinic phase when heated above 500 degrees C. Analysis of visible and UV spectroscopy data reveals that the experimental samples have pronounced absorption in the middle UV range (200-260 nm) and have an energy band gap E-g varying from 4.8 to 5.1 eV. The hydrothermal powders synthesized in this study can be used as absorbers in the mid-UV range and as reinforcing additives in the preparation of technical ceramics.

The world is currently facing a drinking water problem. Human activity, climate change and pollution of existing water bodies are exacerbating the problem. The scientists around the world are currently trying to purify water using effective and inexpensive methods. One such method is membrane distillation. Membrane distillation is a versatile thermally driven membrane separation process. This method of water purification has the potential to remove salts and other non-volatile components. The work is concerned with the desalination of salt solutions by membrane distillation using ion-track membranes based on polyethylene terephthalate (PET). PET ion-track membranes (PET TMs) were modified by photoinitiated graft polymerization of 2,2,3,3,4,4,4-heptafluorobutyl methacrylate (HFBMA) to make them hydrophobic. Optimal polymerization conditions (monomer concentration, reaction time) were determined, which led to an increase of water CA from 51 to 105°. The obtained membranes were used to purify the solution from NaCl. The effect of salt concentration as well as membrane properties on performance and degree of purification was studied. The results show that large pore size PET TMs modified with HFBMA has the potential to desalinate water in an efficient manner.

One of the major limitations of anti-cancer drug is their poor selectivity and high toxicity. Present study is aimed overcoming these difficulties by development targeted drug delivery systems. Drug delivery systems were synthesized based on magnetite nanoparticles with grafted poly(2-vinylpyridine) from their pre-modified surface with 3-(trimethoxysilyl)propyl methacrylate. Physical and chemical properties of synthesized samples were examined by FTIR, XRD, VSM, EDA, Mössbauer spectroscopy. 5-FU release from nanocarriers was estimated using UV-Vis spectroscopy.

The paper presents the results of studies of the resistance of lithium ceramics to helium swelling during its accumulation in the structure of the near-surface layer, and the identification of the three types of lithium ceramics most resistant to radiation degradation: Li4SiO4, Li2TiO3, and Li2ZrO3. The simulation of helium swelling under high-dose irradiation was carried out by irradiation with He2+ ions with fluences of 1 × 1016 ion/cm2–5 × 1017 ion/cm2, which allows for simulating the implanted helium accumulation with a high concentration in the damaged surface layer (about 500 nm thick). The samples were irradiated at a temperature of 1000 K, the choice of which was determined by the possibility of simulating radiation damage as close as possible to real operating conditions. Such accumulation can result in the formation of gas-filled bubbles. Through the application of X-ray phase analysis, indentation testing, and thermophysical parameter assessments, it was ascertained that among the three ceramic types, Li4SiO4 ceramics exhibit the highest resistance to helium-induced swelling. These ceramics experienced less significant alterations in their properties compared to the other two types. An analysis of the correlation between the structural and strength parameters of lithium-containing ceramics revealed that the most significant changes occur when the volumetric swelling of the crystal lattice becomes the dominant factor in structural alterations. This phenomenon is manifested as an accelerated degradation of strength characteristics, exceeding 10%. At the same time, analysis of these alterations in the stability of thermophysical parameters to the accumulation of structural distortions revealed that, regardless of the type of ceramics, the degradation of thermophysical properties is most pronounced under high-dose irradiation (above 1017 ion/cm2).

The article outlines findings from a comparative analysis of the effectiveness of doping CeO2 ceramics with a stabilizing additive Y2O3 on alterations in the strength and thermophysical parameters of ceramics under high-temperature irradiation with heavy ions comparable in energy to fission fragments of nuclear fuel, which allows, during high-temperature irradiation, to simulate radiation damage that is as similar as possible to the fission processes of nuclear fuel. During the studies, it was found that the addition of a stabilizing additive Y2O3 to the composition of CeO2 ceramics in the case of high-temperature irradiation causes an increase in stability to swelling and softening because of a decrease in the thermal expansion of the crystal lattice by 3–8 times in comparison with unstabilized CeO2 ceramics. It has been determined that the addition of a stabilizing additive Y2O3 leads not only to a rise in the resistance of the crystal structure to deformation distortions and swelling, but also to a decrease in the effect of thermal expansion of the crystal structure, which has an adverse effect on the structural ordering of CeO2 ceramics exposed to irradiation at high temperatures.