The photolysis of a phenanthroline-containing imidazole in a DMSO solution and the initiating ability of the compound in the photopolymerization of multifunctional (meth)acrylates under LED irradiation (λ = 395 nm) in aerobic conditions have been studied for the first time. The relationship between the kinetic parameters of photopolymerization and light intensity and the chemical structure and viscosity of multifunctional monomers has been established.
A Raman spectroscopic study of radiation-synthesized tetrafluoroethylene telomers with different terminal groups was carried out for the first time. The influence of gamma radiation on the molecular structure of telomers and hydrophobic coatings of aluminoborosilicate glass fabric based on them has been studied. Changes induced by gamma radiation in the molecular and morphological structures of the telomers have been observed.
The results of a study on the kinetics of the decrease in strength of polyamide fibers made from polyamide PA-6 (poly-ε-caprolactam) irradiated in air with X-rays in the range of absorbed dose rates of 0.16–10 Gy/s are presented. It has been shown that the strength of irradiated polyamide fibers decreases to a certain limiting value depending on the dose rate and can be described by the rate law of a reversible pseudo-first-order reaction. A structural–kinetic model of radiation-oxidative aging of fibers is considered, which takes into account the opposite influence of degradation and crosslinking of tie macromolecules on the strength of the oriented polymer (fiber) and the structural features of the oriented polymer. The model agrees well with experiment and makes it possible to describe the change in the strength of an oriented polymer (fibers) and a unidirectional composite based on them while the processes of radiation-oxidative degradation and chain crosslinking occur simultaneously.
Luminescent polymer composites based on polycarbonate and polystyrene doped with boron difluoride β-ketoiminates have been synthesized. The luminescence properties of 12 dyes with various substituents have been studied. The effect of the boron difluoride β-ketoiminate concentration on the spectral properties of the samples has been studied. It has been found that the studied dyes exhibit monomer luminescence even with a tenfold increase in the luminophore concentration (from 0.05 to 0.5%). It has been revealed that composites containing boron difluoride 3-amino-1-phenyl-2-buten-1-onate (1a) and boron difluoride 3-methylamino-1-phenyl-2-buten-1-onate (2a) dyes in polystyrene exhibit exciplex luminescence.
Gallium selenide (GaSe) thin films on silicon(111) have been first grown by plasma-enhanced chemical vapor deposition (PECVD) using high-purity elemental gallium and selenium as the precursors. The reactive plasma components formed in the gas phase have been studied by optical emission spectroscopy. All grown films have a stoichiometry similar to that of GaSe. An increase in the plasma discharge power to 50 W and higher leads to the formation of an ε-GaSe phase, an improvement in the structural quality of the films, and an increase in the grain sizes with simultaneous grain compaction.
The results of a Fourier-transform IR spectroscopic study of polypropylene (PP) subjected to gamma-irradiation and post-irradiation high-temperature shear grinding are presented. The IR spectra of PP granules irradiated in air exhibited absorption peaks of hydroxyl and oxygen-containing groups, the intensity of which noticeably decreased in the powder obtained by grinding the irradiated polymer granules. The toxic properties of PP obtained by high-temperature shear grinding of irradiated polymer granules were investigated. It was found that gamma-irradiation of polymer granules in air did not affect the toxic properties of polymer powder obtained by grinding granules irradiated with a dose of 700−4500 kGy. It was established that PP powder obtained from unirradiated and irradiated granules was a moderately toxic substance when administered intragastrically to BDF1 mice.
Changes in the composition of the surface layer of a polyethylene film after treatment in the positive column of a direct current glow discharge in a stream of oxygen and argon have been studied. The possibility of copolymerization of a diallyldimethylammonium chloride monomer and a plasma-modified polyethylene surface is demonstrated.
The results of simulation of radiation-chemical transformations in the primary coolant of a water-cooled water-moderated energy reactor (VVER) are presented. It has been shown that under conditions of intense irradiation, molecular nitrogen dissolved in the coolant exhibits chemical activity. The reaction of N2 with the excited hydroxyl radical initiates the formation of ammonia and nitrous acid. Further decomposition of ammonia produces only oxidized forms of nitrogen, with N2 acting as an intermediate product. Maintaining hydrogen and oxygen concentrations within normal limits in the ammonia water chemistry is possible only with constant dosing of NH3 and degassing of the coolant. In the case of water chemistry with H2 dosing (at the initial moment), on the contrary, a stationary regime is quickly established in the absence of disturbances, satisfying the requirements of VVER water chemistry standards. The difference between the two water chemistry systems is due to the presence of nitrogen in the NH3 molecule and its transformations as an element, regardless of the initial chemical form.
Electron beams with energies up to 3 MeV, widely used in technological and research practice, have a relatively low penetration depth into matter, and the inhomogeneity of energy absorption can reach 30% per 1 mm of path. High heterogeneity, as well as the high cost of radiation, requires the researcher to have skills in optimizing the uniformity of irradiation and reducing energy losses. This work presents the dependences of the average absorbed dose and dose heterogeneity for irradiation of liquid with a horizontal beam in test tubes or tubes with different glass wall thicknesses (0.2–2 mm Pyrex). The dependences are applicable to refining, predicting, and analyzing the distribution of absorbed dose in materials.
In the development of lithium ion batteries (LIBs) with higher energy density and safety, solid-state lithium batteries (SSLBs) have attracted widespread attention. However, even in SSLBs, when metallic lithium is used as the anode, lithium dendrites can still form during the lithium-ion deintercalation process, leading to poor cycling performance of the battery. Herein, lithium-boride (Li-B) alloy with a layered three-dimensional skeleton structure was synthesized and investigated as anode for SSLBs. Due to the stability of the special three-dimensional skeleton structure, the deintercalation of lithium ions does not cause the collapse of the material structure. Thus, compared to the metallic lithium anode, the Li-B alloy exhibits higher discharge specific capacity and better cycling performance (when using the as-prepared lithium-rich manganese-based (Li1.2Ni0.2Mn0.6O2) as the cathode material, the initial discharge capacity of the SSLBs is 209 mAh g–1, and when using LiFePO4 as the cathode material, the initial discharge capacity is 192 mAh g–1, with a capacity retention rate of 82% after 50 cycles).
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