Том 90, № 4 (2017)

Procedure was developed for surface dyeing of polycarbonate glass with photochromic thermally relaxing compounds from the classes of spiropyrans, spirooxazines, and chromenes via diffusion of photochromic molecules from solutions in cyclohexanone. It was shown that the highest diffusion efficiency of photochromic compounds without loss of the optical surface quality of polycarbonate glass is reached at a temperature of 80°C. Samples of photochromic polycarbonate glasses were obtained and their photochromic properties were studied.

The destruction of complexons derived from succinic acid under the action of UV radiation was studied. IR spectroscopy, thin-layer paper chromatography, and complexometric titration were used to determine the destruction products of these complexons. It was found that the complexons decompose under UV irradiation substantially more easily than ethylenediaminetetraacetic acid does, and the products of their decomposition can undergo a biological utilization under natural conditions. The data obtained in the study make it possible to choose, instead of ethylenediaminetetraacetic acid, ligands that will be nearly fully destructible in the light without deteriorating the ecology.

Application of the oxidative modification of sulfate kraft lignin with sodium periodate under mild conditions is suggested in order to obtain a sorbent for detoxication of spillage places of rocket fuels based on 1,1-dimethylhydrazine and to purify wastewaters containing this compound. It was found that processing with the periodate at a temperature of 55°C for 20 h results in a more than twofold increase in the content of carbonyl and quinone groups in a lignin preparation and a rise in its polydispersity due to the appearance of a macromolecular condensed fraction and a threefold increase in the sorption capacity for 1,1-dimethylhydrazine. The sorbent can bind 6.7% of 1,1-dimethylhydrazine and substantially surpasses in this parameter other lignin-based sorbents. It was shown that the firm chemical binding of hydrazines hinders desorption of the highly toxic rocket propellant and products of its oxidative transformation from the surface of lignin both into solution and into the vapor phase, thereby providing safe handling of the spent sorbent.

It is shown that Purolite S957 cation-exchange resin containing phosphonic-acid and sulfonic groups is capable of selectively sorbing molybdenum(VI) in the presence of rhenium(VII) in solution.

The optimal pH value of the concentrated boron–gluconate bath for electroplating Co–W coatings is established to be 6.5 (the concentrations of the alloying components are raised by a factor of 5 compared with the commonly used electrolyte). The microhardness of binary Co–W alloys obtained from this bath reaches 1000 kg mm^–2, and electrodeposition proceeds with high current efficiency ( 93–95%). We demonstrate the critical role the volume current density plays in determining the microhardness of the binary coatings electrodeposited from this bath under galvanostatic conditions. We attribute this peculiarity of the investigated system to microhardness size effect, which is associated with structural modifications in the plated coatings that can be induced by changing the volume current density. Using the concentrated bath improves efficiency of electrodeposition.

The effect exerted by treatment with cyclic anodic current in 1 M H₂SO₄ in the interval 0.0–2.0 V on electrodes made of a porous (55 vol %) composite material consisting of A-437E acetylene black and polytetrafluoroethylene (60 wt %) was studied. The cyclic volt–ampere curves were recorded in 3 M KOH and 1 M H₂SO₄ to determine the double layer capacity. The anodic treatment leads to an increase in the volume of pores filled with the electrolyte and in the electrical capacity of the electrode due both to an increase in the area of the surface wetted with the electrolyte and to the pseudocapacity caused by oxidation of the carbon black surface.

The corrosion resistance of nickel coatings on a copper substrate, plated from low-temperature electrolytes based on acetates, tartrates, and isobutyrates, was studied by the methods of electrochemical impedance spectroscopy (EIS) and polarization curves. The tests were performed in a 0.3% NaCl solution. The nickel coatings exhibit high chemical activity, dissolving in the NaCl solution. The electrochemical step is the limiting step of the corrosion process.

Со-Мо/Al₂O₃ and Ni-W/Al₂O₃ catalysts were tested in hydrotreating of light cycle oil from catalytic cracking, of the straight-run gasoil, and of their mixture under typical hydrotreating conditions used in industry. The catalysts prepared using PMo₁₂ and PW₁₂ heteropoly acids exhibit high catalytic activity. The Со-Мо/Al₂O₃ catalyst is more active in hydrodesulfurization and hydrogenation of olefin and diene hydrocarbons, whereas the Ni-W/Al₂O₃ catalysts are more active in hydrogenation of mono- and polycyclic aromatic hydrocarbons. Comparison of the quality characteristics of the hydrogenizates obtained with the requirements of the technical regulations shows that the required levels of the sulfur content and cetane number of the hydrogenizates at practically accessible process parameters can be reached for mixtures of the straight-run gasoil and light cycle oil from catalytic cracking with high content of the latter component only when the process with the Со-Мо/Al₂O₃ system and Ni-W/Al₂O₃ catalysts is performed in two steps.

Samples of carbon–oligomer filler prepared by ketonization of tire rubber crumb with dinitrogen monoxide were characterized. The effect of the oligomeric component of the filler on the kinetic parameters of cross-linking in model compounds was determined. A study of the main rheological and physicomechanical properties of elastomer compounds based on butadiene–α-methylstyrene rubber containing carbon–oligomer filler demonstrated the possibility of using it as a component of polyfunctional action.

Methacrylate-containing oligosilsesquioxanes were synthesized by acidohydrolytic copolycondensation of γ-methacryloyloxypropyltrimethoxysilane and phenyltrimethoxysilane in a mixture of bismethacrylate monomers, 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]propane and triethylene glycol dimethacrylate, and were characterized by NMR spectroscopy and MALDI-TOF mass spectrometry. Performing the process in the bismethacrylate medium favors formation of uniform blends. Their introduction in an amount of 3 wt % into filled methacrylate dental composites considerably improves the physicomechanical characteristics of these composites.

The electrochemical synthesis of poly(4-aminomethyl-5-hydroxymethyl-2-methyl pyridine-3-ol) on steel and copper electrodes was achieved in both sulfuric acid and oxalic acid by cyclic voltammetry technique. Characterization of the polymer films were achieved by Fourier transforms infrared spectroscopy technique (FTIR) and scanning electron microscope (SEM). Corrosion performance of coatings was investigated in 0.1 M H₂SO₄ by potentiodynamic polarization and electrochemical impedance (EIS) spectroscopy techniques.

In the present work, a new composite material poly(3T + 6T + TiO₂) was electrochemically synthesized. This composite material was synthesized in a solution of (CH2Cl2/TBAP) containing the monomers (terthiophene), (sexithiophene) and semiconductor (TiO₂) particles. The preparedsamples were characterized electrochemically by cyclic voltamperometry (CV) and spectrometry analysis by scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, energy dispersive X-ray spectroscopy (EDX) and fourier transform infrared spectroscopy (FTIR), respectively. The effect of TiO₂ concentration in the solution on dispersed microparticle entity and on the photocurrent response was investigated. The results showed that TiO₂ particles were dispersed and codeposited into the copolymer poly(3T + 6T + TiO₂) matrix, and titanium atom was confirmed by EDX spectra. From SEM images, the TiO₂ has a spherical shape and micrometer size. The FTIR spectrum indicated that titanium dioxide do not show a significant modification in terms of band shape and no interaction between polymers and TiO₂ particles. Furthermore, the results showed that the composite films with different amounts of TiO₂ exhibit good photocurrent properties which imply that these composites films can be used in various fields, such as photoelectrochemical applications as photovoltaic cells.

In this paper, nanoscaled titanium dioxide (TiO₂) was synthesized through sol-gel method by using butyl titanate as precursor. The optimized TiO₂ was obtained experimentally. The reaction kinetics and optimal degradation conditions of direct pink 12B were studied. The results show that as-prepared TiO₂ particles with diameter of ~22 nm are characterized by high catalytic activity. The photocatalytic degradation result shows that the degradation rate of direct pink 12B is 97.58% under ultra-violet light (UV).

The kinetics of free moisture removal from a CaO₂ paste under the conditions of convective drying and UHF field at atmospheric pressure were compared. Drying under the action of UHF radiation is characterized by the absence of the heat-up period. The use of the microwave radiation at atmospheric pressure decreases the drying time in production of anhydrous calcium peroxide by a factor of approximately 10 compared to convective drying.