Today, the neutron matter and neutron stars are already substantially rooted in the nuclear physics and astrophysics, and it is logical to have their consideration of them in terms of chemical properties and principles of general chemistry. The formation of a neutron substance, in addition to gravitational neutronization, is considered, other mechanisms, such as the condensation of ultracold neutrons (UCN) and neutronization due to a critical increase in the atomic number in the periodic table (PS). The stability of the neutron substance is substantiated already at the micro level due to Tamm interaction and not only at the macro level due to the gravitational interaction, as it is now considered in astrophysics. A neutron substance is a very concrete physical reality, urgently demanding its rightful place in the PS and studying not only physical, but also chemical, and possibly even in the near future, engineering and technical properties. We also consider the possibility of a "chemical" interaction of UCN with molecules of substances with an odd number of electrons. It is proposed to extend the PS beyond the limits of classical chemical substances and to cover a much wider range of matter in the universe, based on the forgotten ideas of D.I. Mendeleev. Moreover, PS begins with neutron and its isotopes (dineutron, tetraneutrone, etc.) and ends the neutron stellar substance.

As part of the methodology to control gas permeability of functional materials, mathematical approach is considered that takes into account a diffusion process through a plate with the boundary conditions of the 1st and 2nd types. The methodology under discussion provides methods for estimating parameters of the diffusion by using methods of exceptional points, functional scale and statistical moments. Computer software package HPRON has been developed to provide mathematical modeling, planning, processing and data interpretation of different variants of gas permeability method. The results are used to optimize the performance of the membrane electrode assembly (MEA) for the automotive fuel cell and electrolyzer applications with a perfluorinated proton-conducting membrane such as nafion.

As part of the methodology to control gas permeability of functional materials, a mathematical approach is considered that takes into account a diffusion process through a plate with the boundary conditions of the 1st and 2nd order. The methodology under discussion provides methods for estimating parameters of the diffusion by using methods of singular points, functional scale and the statistical moments. A computer software packages HPRON was developed that provides mathematical modeling, planning, processing and interpretation of the results of different variants of the method of gas permeability. The results are used to optimize the performance of the membrane electrode assembly (MEA) for the automotive fuel cell and electrolyser applications with with a perfluorinated proton-conducting membrane such as Nafion.

Samples of solid solutions of the series Sr(Fe1 − x Co x )0.9Ga0.1O2.5 with brownmillerite structure are produced from appropriate amounts of oxides Fe, Co, Ga, and SrCO3 in different gaseous media and temperature conditions using solid-phase synthesis. Features of the distribution of cations over nonequivalent positions of the crystalline structure of the obtained samples are studied using the 57Fe Mössbauer absorption and emission spectroscopy.

Automation and processing software was developed for interpretation of the results of reactor experiments on tritium release study. Tritium was continuously generated as a result of nuclear reaction of lithium-6 and thermal neutrons under variable thermal impacts on lithium metatitanate. Main gas release parameters, which are necessary for assessment of applicability to use the lithium titanate granules in tritium blankets, were calculated: tritium retention/release ratio, retention time, activation energy of HT thermodesorption, activation energy of T+ bulk diffusion, and corresponding pre-exponential (frequency) factors. It was shown that tritium diffusion coefficient was actively increasing during first 10 months of reactor irradiation of lithium metatitanate, then effective diffusion coefficient stabilized at the value of 1.3×10-7 cm2/s and afterwards the coefficient didn’t change or changed insignificantly.

Annealing in argon of MnTiO3 impregnated with a SnCl4 solution leads to the distribution of Sn4+ ions over sites with different cationic environments in the surface layers of crystallites. The chemical behavior of Sn4+ ions emerging on the surface upon subsequent annealing in hydrogen depends on the tendency of the neighboring cations to retain the octahedral coordination by O2− anions. The absence of spin polarization of the Sn2+ cations formed on the surface shows that their specific valence state is stabilized by the nearby Ti4+ cations.

The effect of grindingon thermal behavior of pyrophyllite and talc as commonly used ceramic clayminerals was investigated by DTA, TG, emanation thermal analysis (ETA), B.E.T.surface area (s.a.) measurements, X-ray diffraction (XRD) and scanning electronmicroscopy (SEM).

Structural changes in perovskite and perovskite-like ceramics in the course of thermal treatment were studied by emanation-thermal analysis (ETA) using synthetic calcium metatitanate and aluminotitanate with addition of neodymium and cerium simulating solidified radioactive wastes. The emanation was analyzed as influenced by mechanical (polishing of the surface with diamond paste), radiation (bombardment with helium and krypton ions to certain dozes), and chemical (leaching in aggressive solvents) treatments and by the atmosphere (air, argon, hydrogen) in which the thermal treatment was performed. The ETA curves exhibit characteristic peaks corresponding to regeneration and annealing of both natural structural defects and those appearing after the external treatment of the sample. The model of emanation from material involving structural transformations, which well agrees with experimental data, was proposed. The emanation-thermal analysis under the dynamic conditions allows study of the evolution in the development of the surface relief and solid-state processes proceeding in the fine near-surface layer of material in the course of thermal treatment. It was found that the perovskite-like ceramics, thanks to its high thermal, radiation, mechanical, and chemical stability, can be recommended for solidification and disposal of high-level radioactive wastes.

Structural changes in basalt sorbents in the course of thermal treatment were studied by complex emanation-thermal analysis. Sorbent was prepared by two-stage treatment of staple basalt fibers with hydrochloric acid. The sorption isotherms of liquid nitrogen vapor on these new sorbents were obtained, the open surface areas were determined, and the porosity and pore size distribution of leached fibers were evaluated. The data of thermostimulated gas liberation method showed that water sorbed on porous basalt fibers occurs in two energy-different states: the main fraction of water is desorbed at 90-110°C, and the remainder, at 300-320°C. The sorbent is completely regenerated on heating to 550°C. Degradation of the fiber pore structure begins at 700°C, and fiber sintering, at temperatures greater than 1150°C. A mathematical model of emanation of the porous systems in the sintering mode was proposed, and the activation energies of emanation of the initial and porous fibers were calculated. It was found that leaching, along with formation and development of the mesopore system, generates numerous “point” defects. Due to significant sorption activity and high thermal stability, fibrous basalt sorbents can be recommended to prepare sorption filters for treatment of radiochemical production wastes.

Experimental features of radiotracer gas-sorption defectoscopy and selection of the optimal probe gas, tracer, period and temperature of sorption, period and temperature of desorption, and period and temperature of exposure of the labeled sample with the photographic material were analyzed. Feasibility of this method was studied by the examples of low-density polyethylene containing various inclusions, filed composite, and irregularly irradiated polymer. The vapors of carboxylic acids labeled with C-14 and tritium were used as probes. It was found that gas-sorption defectoscopy under the optimal probing conditions allows correct development of various defects in the polymer structure.

The methodological features of various procedures of the radiotracer sorption defectoscopy in diagnostics of the surface and thin near-surface layer of heterogeneous materials based on polymers were analyzed. Primary attention was focused on the use of local sorption isotherms and diffusion probe gases labeled with alpha- and beta-emitters to determine the regional and local structure defects, of two probe gases (hydrophilic and hydrophobic) to monitor the results of nonuniform irradiation of the cable insulation, and simultaneous use of two probe gases (hydrophilic gas labeled with a beta-emitting isotope and an alpha-emitting heavy noble gas) to reveal the defects deteriorating the operation characteristics of the polymeric materials. As found, tracer sorption defectoscopy allows distinguishing the areas with elevated adsorption from the areas with increased content of defects provided by irradiation and with facilitated diffusion, promoting penetration of aggressive solutions into the bulk of construction materials.

The state of radon in crystalline polymers, polyethylene and polypropylene, has been studied by methods of macro- and microauto-radiography. Radon-222 was introduced into the samples by diffusion from the gas phase at various temperatures and time intervals. Effects on the state of radon of such factors as density and polymer crystallinity, extent of macromolecular chain branching, spherulite radius, content of different admixtures, γ-ray photon irradiation dose or irradiation with accelerated electrons, etc., were investigated. In pure polymers, radon was found to be in an atomically dispersed state. Radon forms thermally stable accumulations at the surface as well as in the bulk of the material due to admixtures, gas bubbles and crazes. The probable effect of radon's tendency to form accumulations on the kinetics of its diffusion in crystalline polymers is discussed.