This study is devoted to clarifying the crystal structure of diamond particles synthesized by shock wave compression of graphite. Employing a comprehensive suite of methods—including energy dispersive X-ray spectroscopy, XRD, TEM and SEM, laser diffraction, DLS, Raman spectroscopy, nitrogen adsorption-desorption analysis, and SAXS—the research determines the particle size distributions, elucidates the nanocrystalline structure of the diamond particles, and characterizes their impurity compositions. The findings demonstrate that the intrinsic structural differences between diamond produced by detonation of explosives and those obtained through shock wave compression of graphite lead to a significantly lower efficiency of thermal disaggregation for the latter particles. Moreover, inclusions of hexagonal diamond (2H), also known as lonsdaleite, were observed within the crystal structure of the studied particles.

Small angle X-ray scattering optical and Mossbauer spectroscopy has been used to study ionic channels in perfluorinated Nafion (R)-type membranes. X-ray scattering data have revealed the ordering of ionic groups of polymer chains at nanoscales into extended fine channels for proton conductivity. Then the membranes were saturated with Fe3+ ions to probe their interaction with sulfonic groups. This remarkably changed electron properties of copolymer in which the energy of optical gap has decreased. The Mossbauer spectra have confirmed that even at ambient temperature in membrane, Fe3+ ions are assembled into antiferromagnetic dimers with water shells and associated with sulfonic groups at the channel surfaces. The applied complementary methods allowed us to examine a short-range order of ionic groups forming a network of channels in membranes that provide their functional properties in hydrogen fuel cells.

New method of emulsion synthesis of Nafion®-type copolymer composition by using nanodiamond platform has been proposed and implemented. Produced polymeric coagulate saturated with diamonds (4.1 % wt.) possessed increased ionic capacity of the copolymer comparative to the analogue without diamonds. SEM patterns for coagulate membranes showed labyrinthine structures with diamonds integrated into copolymer without any segregation. This structuring provided necessary elastic and strength properties of new type membranes for hydrogen fuel cells. In new membranes synchrotron experiments exhibited a network of ionic channels which ensured a proton conductivity by one order of magnitude higher than that for the analogue produced of premade components.

A new method of using the detonation nanodiamond with positive and negative zeta potential as a spacer for aerogels based on graphene oxide is presented. It is shown that the dosed addition of detonation nanodiamonds' particles to the suspension of graphene oxide hydrosol made it possible to triple the specific surface area of the resulting aerogel compared to graphene oxide aerogel, and this effect is more significant when nanodiamonds with a positive zeta potential are used. It was also shown that aerogels derived from graphene oxide and detonation nanodiamond with a positive zeta potential have a specific morphology with graphene oxide platelets being twisted. This effect is discussed in terms of the change in the average zeta potential of the initial mixtures. Keywords: two-component systems, carbon materials, colloid chemistry.

— The work describes the results of the research of radon-220 emanation from a polymer membrane source with complex porous structure with adsorbed parent radionuclide thorium-228. It is shown that this type of source can be used for the isolation of target radionuclide lead-212 with high radionuclide purity for various nuclear-medicine applications.

In this study, we aimed to design and research proton-conducting membranes based on Aquivion®-type material that had been modified with detonation nanodiamonds (particle size 4–5 nm, 0.25–5.0 wt. %). These nanodiamonds carried different functional groups (H, OH, COOH, F) that provided the hydrophilicity of the diamond surface with positive or negative potential, or that strengthened the hydrophobicity of the diamonds. These variations in diamond properties allowed us to find ways to improve the composite structure so as to achieve better ion conductivity. For this purpose, we prepared three series of membrane films by first casting solutions of perfluorinated Aquivion®-type copolymers with short side chains mixed with diamonds dispersed on solid substrates. Then, we removed the solvent and the membranes were structurally stabilized during thermal treatment and transformed into their final form with –SO3H ionic groups. We found that the diamonds with a hydrogen-saturated surface, with a positive charge in aqueous media, contributed to the increase in proton conductivity of membranes to a greater rate. Meanwhile, a more developed conducting diamond-copolymer interface was formed due to electrostatic attraction to the sulfonic acid groups of the copolymer than in the case of diamonds grafted with negatively charged carboxyls, similar to sulfonic groups of the copolymer. The modification of membranes with fluorinated diamonds led to a 5-fold decrease in the conductivity of the composite, even when only a fraction of diamonds of 1 wt. % were used, which was explained by the disruption in the connectivity of ion channels during the interaction of such diamonds mainly with fluorocarbon chains of the copolymer. We discussed the specifics of the mechanism of conductivity in composites with various diamonds in connection with structural data obtained in neutron scattering experiments on dry membranes, as well as ideas about the formation of cylindrical micelles with central ion channels and shells composed of hydrophobic copolymer chains. Finally, the characteristics of the network of ion channels in the composites were found depending on the type and amount of introduced diamonds, and correlations between the structure and conductivity of the membranes were established.

Binary and ternary complexes of europium fullerenes and diphthalocyanines with detonation nanodiamonds are obtained for the first time, which can serve as platforms for the delivery of these hydrophobic molecules into aqueous biological media for magnetic resonance imaging, photodynamic therapy, and diagnostics using luminescent labels. Detonation nanodiamonds ( 4–5 nm in size) have a positive potential (30–70 mV) in an aqueous medium due to the groups (CH, COH) grafted to the surface by heat treatment in an atmosphere of hydrogen. When positively charged diamonds interact with electronegative hydrated fullerenes in an aqueous medium, the initial aggregates of each of the components are destroyed, and the electrostatic attraction between them leads to the formation of stable compact complexes 20 nm in size, according to dynamic light scattering and neutron scattering in colloids (20°C). Binary complexes include, on average, two fullerene molecules per 30–40 diamond particles. Introducing diphthalocyanine molecules into a binary colloid yields stable ternary structures. The resulting complexes of diamonds, fullerenes, and diphthalocyanine molecules are promising for biomedical applications due to the luminescent and magnetic properties of the components.

Progress in nanodiamond technologies allows regulate diamond surface properties, amounts of grafted functional groups, and positive (negative) potential of particles in aqueous media. It stimulates the applications of diamonds as advanced nanoplatforms with chemical and radiation resistivity (laser light, UV, X- and γ-rays) and luminescent properties useful for catalysis and biomedicine. The modification of diamonds with fullerenes C60, C70, and endofullerenes M@C2n (n ≥ 30) with captured magnetic metal atoms (M) of 4f and 3d elements is a prospective way to create medical preparations based on carbon and metal–carbon structures as active scavengers of free radicals, photosensitizers, minimally toxic, and effective contrasting agents for MRI diagnostics owing to magnetic atoms encapsulated inside firm carbon cages. Authors have developed the synthesis of fullerenes and endofullerenes with 4f, 3d elements and found new ways to transform pristine carbon structures to water-soluble fullerenols by two-stage hydroxylation. The studies of fullerenols and endofullerenols by optical absorption, Raman spectroscopy, small-angle neutron and synchrotron radiation scattering, and other methods have confirmed their expected structure, the coordination of atoms, and showed fractal molecular ordering in aqueous media. Further, taking various proportions of components, the authors prepared the complexes by the association of electronegative Gadolinium fullerenols with diamonds carrying positive charges. The stability of such structures was proved during cyclic temperature variation (25–70–25 °C) when their ordering in solutions was detected at nanoscales by X-ray scattering. Following NMR measurements (25 °C) on protons in these aqueous systems allowed to find longitudinal (T1) and transversal (T2) relaxation times: T1 < T2 in pure diamond dispersion, T1 ≤ T2 in fullerenol solution, but T1 ≪ T2 in the dispersion of complexes. Thus, by complexing there were prepared so-called negative contrast agents very needed in MRI practice. Final biological tests on cell cultures showed low toxicity of complexes that is desirable for the implementation in theranostics.

Effective X-ray-excited metal–organic scintillators were used to create complexes with nanodiamonds in order to obtain optically active nanoplatforms capable of delivering photosensitizer molecules to living tissues in photodynamic therapy procedures. Hydrophilic detonation nanodiamonds with specially modified surface that had a positive potential in aqueous media due to saturation with grafted hydrogen atoms were associated with hydrophobic phosphors based on linear alkylbenzenes with organic modifiers carrying gadolinium atoms controlled by X-ray fluorescence spectrometry. This made it possible to convert X-rays into photons in the wavelength range of 350–550 nm, including the Soret absorption band of the Radachlorin® photosensitizer. Binary and ternary formations, diamond-scintillator and diamond-scintillator-Radachlorin®, were additionally stabilized with polyvinylpyrrolidone. As a result, functional nanostructures were obtained that are stable in aqueous media in the temperature range of 20–50 °C according to small-angle neutron scattering data and optical absorption measurements. As shown by neutron experiments, ensembles of diamond particles in combination with the indicated modifiers form chain-like fractal structures on scales of tens of nanometers. These structures retain the photoluminescent properties of the scintillator and photosensitizer that is confirmed by measurements of the luminescence in prepared colloids upon UV excitation. The colloids exhibited intense secondary radiation in visible and near-IR ranges. The developed functional materials are being tested on biological cells and animals for subsequent applications in X-ray photodynamic therapy as combined converter-photosensitizers.

Powder diamonds with integrated europium atoms were synthesized at high pressure (7.7 GPa) and temperature (1800 °C) from a mixture of pentaerythritol with pyrolyzate of diphthalocyanine (C64H32N16Eu) being a special precursor. In diamonds prepared by X-ray fluorescence spectroscopy, we have found a concentration of Eu atoms of 51 ± 5 ppm that is by two orders of magnitude greater than that in natural and synthetic diamonds. X-ray diffraction, SEM, X-ray exited optical luminescence, and Raman and IR spectroscopy have confirmed the formation of high-quality diamond monocrystals containing Eu and a substantial amount of nitrogen (~500 ppm). Numerical simulation has allowed us to determine the energy cost of 5.8 eV needed for the incorporation of a single Eu atom with adjacent vacancy into growing diamond crystal (528 carbons).

Aquivion®-type perfluorosulfonic acid membranes with a polytetrafluoroethylene backbone and short side chains with sulfonic acid groups at the ends have great prospects for operating in hydrogen fuel cells. To improve the conducting properties of membranes, various types of nanofillers can be used. We prepared compositional Aquivion®-type membranes with embedded detonation nanodiamond particles. Nanodiamonds were chemically modified with sulfonic acid groups to increase the entire amount of ionogenic groups involved in the proton conductivity mechanism in compositional membranes. We demonstrated the rise of proton conductivity at 0.5–2 wt.% of sulfonated nanodiamonds in membranes, which was accompanied by good mechanical properties. The basic structural elements, conducting channels in membranes, were not destroyed in the presence of nanodiamonds, as follows from small-angle neutron scattering data. The prepared compositional membranes can be used in hydrogen fuel cells to achieve improved performance.

Carbon nanoparticles with antimicrobial properties, such as fullerenes, can be distinguished among the promising means of combating pathogens characterized by resistance to commercial antibiotics. However, they have a number of limitations for their use in medicine. In particular, the insolubility of carbon nanoparticles in water leads to a low biocompatibility and especially strong aggregation when transferred to liquid media. To overcome the negative factors and enhance the action of fullerenes in an extended range of applications, for example, in antimicrobial photodynamic therapy, we created new water-soluble complexes containing, in addition to C60 fullerene, purified detonation nanodiamonds (AC960) and/or polyvinylpyrrolidone (PVP). The in vitro antibacterial activity and toxicity to human cells of the three-component complex C60+AC960+PVP were analyzed in comparison with binary C60+PVP and C60+AC960. All complexes showed a low toxicity to cultured human skin fibroblasts and ECV lines, as well as significant antimicrobial activity, which depend on the type of microorganisms exposed, the chemical composition of the complex, its dosage and exposure time. Complex C60+PVP+AC960 at a concentration of 175 µg/mL showed the most stable and pronounced inhibitory microbicidal/microbiostatic effect.

The paper describes the results of work on the creation of a prototype 212 Pb generator obtained by the emanation method using the gaseous radionuclide 220 Rn. The generator is technologically simple and has convenient operational characteristics. The efficiency of 220 Rn isolation with this design is more than 90%, which indicates the acceptability of such type of sources for obtaining 212 Pb of high radionuclide purity for the needs of nuclear medicine.

Recent results on synthesis, structural, and physicochemical studies of complexes based on detonation nanodiamonds modified with metal-organic molecules with functional magnetic and fluorescent properties have been presented. Neutron scattering experiments have discovered subtle features of the assembly of electro-negative molecules of Eu diphthalocyanines and nanodiamonds with positive surface potential in aqueous media. Nanoscale ordering of diamonds reinforced by their linking via diphthalocyanines was confirmed by TEM. The stable complexes possess X-ray luminescent and magnetic properties. Such nanostructures with low toxicity are prospective as contrasting and photoactive agents for magnetic resonance imaging and photodynamic therapy.

The Aquivion (R)-type perfluorinated proton conducting membranes were studied subjected to a specially developed technique of uniaxial orientational stretching. Membranes were prepared from copolymer produced by aqueous-emulsion copolymerization and by pressing the melt copolymer precursor or by casting a solution of copolymer in sulfonyl alkaline form in dimethylformamide. The possibilities of the regulation of electrochemical and physical-chemical properties of Aquivion (R)-type membranes using the method of orientational stretching are demonstrated. Proton conductivity rises in the stretching direction due to the straightening of the pathways for protons in membranes found by small-angle neutron scattering technique.

Safety conditions and lifetime extension of a Nuclear Facility (NF) are fundamental and a deep knowledge of ageing and creep processes linked with the involved materials and parts is essential to guarantee high levels of reliability and to face severe natural and plant–centred incidences. The analyses classically used in this case, involving non-destructive techniques (NDT) and in-service inspections required by the norms, can present a lack of information. The data acquired, consequently, need to be complemented. Decommissioning of NFs is an important chance to get materials and parts submitted for various years to ageing and degradation, consenting novel diagnostic activities beneficial to suggest eventual additional measures related to the installation of new components or in planning a postponed decommissioning, to increase safety and dependability. Neutron beam techniques (NBT) can be helpful to characterise, in a non–destructive and non-invasive way, materials and parts of nuclear/traditional interest. Positive recommendations exist to exploit neutron methods for reactor materials’ control. In this paper, ageing processes occurring in the NFs sector are briefly introduced and the main neutron techniques are briefly described. Some examples of applications, then are presented. The results obtained by neutron analyses, linked with information on nature and features of materials’ damages, assist to comprehend the trends of fracture and to evaluate a latent picture of preliminary degradation processes leading to any fast crash of material, including inoperability periods before the decommissioning activities.

Compositional proton-conducting membranes based on perfluorinated Aquivion®-type copolymers modified by detonation nanodiamonds (DND) with positively charged surfaces were prepared to improve the performance of hydrogen fuel cells. Small-angle neutron scattering (SANS) experiments demonstrated the fine structure in such membranes filled with DND (0–5 wt.%), where the conducting channels typical for Aquivion® membranes are mostly preserved while DND particles (4–5 nm in size) decorated the polymer domains on a submicron scale, according to scanning electron microscopy (SEM) data. With the increase in DND content (0, 0.5, and 2.6 wt.%) the thermogravimetric analysis, potentiometry, potentiodynamic, and potentiotatic curves showed a stabilizing effect of the DNDs on the operational characteristics of the membranes. Membrane–electrode assemblies (MEA), working in the O2/H2 system with the membranes of different compositions, demonstrated improved functional properties of the modified membranes, such as larger operational stability, lower proton resistance, and higher current densities at elevated temperatures in the extended temperature range (22–120 °C) compared to pure membranes without additives.

A prototype of a diffusion-type 212Pb generator is developed. The generator is based on the emanation of parent 220Rn from an ion-exchange resin. It is found that the emanating capacity of an AB-17-8 strongly basic 228Th-containing anion-exchange resin grows along with its moisture content. The yield of 220Rn on thin layers can reach 52% under normal conditions. It is shown that thickening the resin layer considerably reduces the yield of 220Rn. Ninety percent of the 212Pb deposited on the collector walls can be washed off with a 0.1 M solution of HCl for further use in creating complexes with organic compounds for targeted molecular cancer therapy. Alpha spectrometric measurements show there are no long-lived parent impurities in the eluate, testifying to the potential of using the generator.