Voprosy khimii i khimicheskoi tekhnologii (Issues of Chemistry and Chemical Technology)

10-15

Authors: L.O. Melnyk

The influence of the supporting electrolyte on the efficiency of arsenate retention by nanofiltration membrane OPMN-P is investigated in the paper. It is shown that the increase of sodium chloride concentration in the solution from 1 up to 3 g/L or the replacement of sodium chloride by a mixture of NaCl and Na2SO4 has no effect on the process. The coefficient of arsenate retention considerably diminishes in the presence of Ca2+ ions that can be caused by its interaction with the functional groups of a membrane and a decrease of negative value of its zeta potential. After the replacement of sodium chloride as a supporting electrolyte by sodium bicarbonate, the arsenate retention coefficient decreases from 97.5 to 92.2-93.1%. The removal of As(V) from real underground water of bicarbonate type reaches 93.3-95.7% at permeate recovery of 90% and arsenic concentration in the initial solution of 116 to 220 μg/L. This provides obtaining permeates that meet the standards of drinking water quality with regard to the contents of the microcomponent under consideration. The utilization of arsenic compounds from concentrates of membranous installations can be performed by the hydrothermal mineralization method which provides obtaining Ca5(AsO4)3(OH). The volume of membranous installations may be minimized owing to high As(V) retention coefficient by ОPMN-P membrane at permeate recovery of 90%.

20-25

Authors: A.V. Slipkan, D.E. Kytova, A.V. Shtemenko

The process of the intercalation of dirhenium(III) complex compounds of cis-configuration with general formula cis- Re2(RCOO)2Cl4∙2DMSO (where R = СH3, C2H5, С(CH3)3, і-C3H7) into a zirconium phosphate framework with an interlayer distance of 10.3 Å (θ-ZrP) has been investigated. To confirm the presence of dirhenium(III) complexes intercalated into θ-ZrP, the obtained systems complex/ZrP with loading level of 1:5 and 1:30 were investigated by X-ray powder diffraction method, UV-Vis, IR spectroscopies and analysis of thermal transformations. The obtained data indicate the formation of a new phase with the percentage of inclusion of dirhenium(III) compounds till 21%. The intercalation of dirhenium(III) compounds leads to an increase in the interlayer distance from 10.3 Å to 11.63 Å, 13.6 Å and 16.67 Å for cis- Re2(СH3COO)2Cl4∙2Н2О, cis- Re2(С(CH3)3COO)2Cl4∙2DMSO and cis- Re2(і-C3H7COO)2Cl4∙2DMSO, respectively. The analysis of the structure of the initial compounds shows that the intercalation of cis- Re2(RCOO)2Cl4∙2DMSO compounds can occur both by the substitution of equatorial or axial ligands by monodentate coordinated phosphate groups ZrP and by the coordination of fourth oxygen atom which is directed into the interlaminar space. Dirhenium(III) complex compounds remain stable in the layered θ-ZrP at room temperature maintaining biologically active cluster center Re26+. Thus, zirconium hydrogen phosphate, as a type of layered materials, is a promising carrier for non-invasive use of dirhenium(III) cluster compounds as antitumor agents.

31-52

Authors: R.D. Apostolova, N.D. Zaderey, I.V. Kirsanova

We report the analysis of the literature data on electrochemical performance of silicon with a high power intensity (4190 mA h g-1) and SiO, SiO2 oxides in negative electrodes of lithium-ion batteries (LIB) in order to estimate the outlook on the replacement of the graphite (372 mA h g-1) by Si and its oxides in commercial lithium-ion batteries. The problems of the capacity loss of Si-, SiO-, SiO2-electrodes were discussed, the loss at cycling being related to the volume expansion of electrode materials, the formation of SEI interface film. The ways of the solution to those problems are considered. The volume expansion may be decreased by the use of the nanostructures of different forms (nanoparticles, nanowires, nanotubes and others), the elaboration of thin films, the composites with carbon materials, and the composites with electrochemically active and inactive metals, the porous electrodes and also other special structure architectures. The core-shell structures coated by conducting materials are shown to be a striking example of an important improvement in Si-electrode performance in LIB. The stable and reversible capacity of Si-electrodes depends on the binders; a number of binder's materials were proposed for silicon composite electrodes. Successful Nexeon–technologies of the production of Si-electrodes allow obtaining the stable discharge capacity of more than 3500 mA h g-1 in lithium batteries. However complicated production procedures and high cost of the nanostructure architectures production delay the scalable practical use of Si-, SiO-, SiO2-electrodes in LIB.

59-62

Authors: P.I. Bashtanyk, I.I. Malyarevych, О.V. Chervakov, M.V. Andriianova, К.О. Gerasimenko, Т.G. Filinska

The effect of bio-plasticizer based on renewable raw materials of vegetable origin on a number of physical and mechanical properties of polyvinyl chloride (PVC) plasticized was investigated. Non-phthalate products based on fatty acids derivatives of vegetable oils were used as such bio-plasticizers. The influence of technological parameters of rolling process (temperature and rolling time) on physical and mechanical properties of PVC plasticized was determined. We stated the rational parameters of rolling process to be as follows: rolling temperature of 160 to 170 °C and rolling time of 3 to5 minutes. The introduction of the alternative plasticizer increases physical and mechanical properties of PVC plasticized. We carried out the modification of PVC plasticized by partial replacement of the most widely-used industrial plasticizer – diisodecyl phthalate by another bio-plasticizer – epoxidized derivatives of fatty acid methyl esters (EFAME). The effect of EFAME on physical-mechanical properties and combustibility of PVC plasticized was investigated. With increasing amount of bio-plasticizer in the composition of PVC plasticized, its physical and mechanical characteristics improve. The application of a mixture of traditional plasticizer and bio-plasticizer, namely EFAME and diisodecyl phthalate, seems to be the most promising and cost-effective way. This approach allows obtaining films based on PVC plasticized with reduced cost, enhanced mechanical properties being maintained.

68-73

Authors: E.V. Kolomiyets, K.M. Sukhyy, E.A. Belyanovskaya, V.I. Tomilo, M.P. Sukhyy

The design of a sorption heat regenerator for ventilation systems is shown; its operation and the results of the full-scale tests are described. The technology of the regeneration of low-potential heat and moisture by composite sorbent "silica gel/sodium sulfate" has been suggested. The synthesis of the composite sorbent "silica gel/sodium sulfate" is presented. The experimental plots of the changes in temperature, absolute and relative humidity at the inlet and outlet of the apparatus and between fillings with the composite are given in the paper. The correlation between flows switch-over time, airflow rate and temperature drop has been established. The relationship between heat recovery coefficient and dimensionless temperature drop as well as the relationship between moisture regeneration coefficient and dimensionless absolute humidity drop has been derived with sufficient accuracy for engineering calculation. The ability of purposeful modification of the above-mentioned ratios within broad ranges by changing the half-cycle time, the size of the granules of the adsorbent and its amount is revealed. The results of the study can be used in the development of energy-saving ventilation systems for residential and storage premises.

78-86

Authors: N.G. Nosova, V.J. Samaryk, S.M. Varvarenko, M.V. Ferens, A.V. Voronovska, M.I. Nagornyak, S.V. Khomyak, Z.J. Nadashkevych, S.A. Voronov

The porous polymeric hydrogels are considered very promising for the application in drug delivery, separation and purification of proteins and tissue engineering. Their advantages include the following: high speed of saturation by fluids (medicines, wound exudate, etc.), increasing rate of the drugs release when contacting with the affected areas, reduction of the mechanical irritation of damaged areas contacting with them, the possibility of their utilization for the treatment of deep wounds. The aim of our work was to obtain porous hydrogel materials whose properties, such as atraumaticity, injury-simulate properties and the ability to fill them with medicines, allow their using in biomedical purposes. The article presents the results of our studies that allowed determining the optimal conditions of the preparation and characterization of the hydrogel matrix formation, this matrix being suitable for filling with the appropriate modifiers and fillers. The prepolymers of acrylamide with various molecular weights were synthesized and the rheological characteristics of their solutions were investigated. This allowed optimizing the system for hydrogel obtaining. The porous hydrogels were synthesized via structuring mechanism from previously obtained water soluble and react-capable prepolymers, such as acrylamide and N-hydroxy- methylene acrylamide, under the conditions of stabilizing and forming a porous structure using surface-active co-polyester. The features of their obtaining were studied (such as the ratio of reactants, temperature, structuring time) to ensure controlling their properties as follows: porosity, swelling capacity, physical and mechanical properties. The obtained porous hydrogel materials can be used as transdermal medicines, anti-burn and blood-stopping bandages when they are filled with appropriate drugs.

93-97

Authors: A.A. Pasenko, M.I. Skiba, A.K. Makarova, V.I. Vorobyova, A.A. Pivovarov

The manufacture of Ag nanoparticles is an important goal of modern materials science as they have unique physicochemical, optical and antibacterial properties. This paper reports the main features of producing silver nanoparticles from aqueous solutions by using low-temperature nonequilibrium contact plasma. The method presupposes obtaining silver sols in a single-stage process without specially added reducing agents. The influence of AgNO3 concentration and duration of plasma chemical discharge on the oxidation-reduction potential of silver nitrate aqueous solutions was studied. The UV-visible spectroscopy was used to estimate the properties of colloidal solutions of Ag nanoparticles. The optimal value of the concentration required to produce stable silver nanoparticles has been established. The duration of the treatment by nonequilibrium contact plasma should be in the range of 4 to 6 min. It has been shown that the sols of silver nanoparticles have low aggregative stability. The introduction of polyvinyl alcohol into silver nitrate solution before the treatment by nonequilibrium contact plasma allows obtaining colloidal silver solutions which are stable at least during two weeks.

8-13

Authors: D.O. Kolomieitsev, S.A. Varenichenko, V.O. Astakhina, V.I. Markov, S.I. Kovalenko, O.V. Kharchenko

Thieno [2,3-d] pyrimidines are of great scientific and practical interest because of the similarity in structure to natural compounds, diverse biological activity and high reactivity, which defines the broad synthetic possibilities of synthesis of heterocyclic systems. The paper presents the results concerning the interaction of 4-hydrazino- 6,7-dihydro-5H-cyclopenta [4,5] thieno [2,3-d] pyrimidine with electrophilic reagents. When used this compound as a key synthon, it is possible to obtain a large number of heterocyclic compounds with promising practical application in a one-step and with high yields. For example, it was found that during the reaction with ethyl pyruvate, 2,4-diketoesters and acetyl chloride we observed intermolecular recyclization isomerization giving the corresponding triazin [1,6-b]-series via an acid-catalyzed mechanism analogous to Dimroth rearrangement. At the same time, from the above reaction with maleic anhydride gives [6,1-c] triazin as the end product. The acylation with benzoyl chloride 4-hydrazino-thieno [2,3-d] pyrimidine results in a product which contains a condensed cycle of thieno[2,3-d]pyrimidine triazole.

19-25

Authors: A.V. Tsurkan, E.A. Vasil'eva, A.A. Kityk, S.A. Korniy, V.S. Protsenko, F.I. Danilov

The work shows that the electrochemical synthesis of thin protective layers of cerium dioxide on the surface of Fe/TiO2 composite coatings can be performed using methanesulfonate solutions. Thin layers of ceria with a good adhesion to the substrate are obtained at cathodic current density of less than 0.3 A/dm2 from electrolytes based on cerium (III) methanesulfonate. The presence of cerium on the composites surface was proved by means of energy dispersive X-ray spectroscopy (EDS). The modification of iron matrix of a composite by the electrodeposition of thin CeO2 film results in an essential improvement in corrosion resistance; this affords an opportunity to use such composite coatings as photocatalysts for the destruction of organic compounds in wastewater treatment. The photocatalytic activity of the developed Fe/TiO2 composite coatings with a surface CeO2 layer was shown in the reaction of photochemical destruction of methyl orange dye under the action of ultraviolet irradiation.

31-37

Authors: O. Shmychkova, T. Luk'yanenko, D. Girenko, A. Velichenko

It has been revealed that the significant delay of the current corresponding to the induction period is observed in the presence of SO42- ions, indicating the increase in the concentration of the intermediate product in the process of electrodeposition of lead dioxide. The introduction of PO43- ions into the solution leads to a significant increase in the induction period and the reaction of Pb(II) oxidation is almost complete inhibited. It is shown that in both cases poorly soluble compounds are formed facilitating the attachment of intermediate products of the electrochemical reaction of Pb(II) oxidation to the electrode surface. In the presence of sulphate ions electroactive compounds are formed, so the induction period of the formation of lead dioxide decreases. With the introduction of phosphate ions there is although a stabilization of the intermediates, but they are inert and block the active sites of the electrode surface, resulting in no increase in the current on the current-time transient. Based on the data of the influence of F- on electrodeposition of lead dioxide, it has been found that the chemisorbed oxygen species with a sufficiently highly bonded to the electrode surface are involved in the chemical step of the formation of intermediate.

43-46

Authors: T.V. Dmytriieva, V.V. Boiko, S.M. Kobylinskyi, S.V. Riabov, V.I. Bortnytskyi, S.K. Krymovska

In the present paper, the influence of metal containing compounds based on copper, zinc, and cobalt acetates and zinc formate on the degradable properties of polyethylene is investigated. It was established that the introduction of these functional additives does not significantly affect the initial strength properties of the composites; however, the addition of cobalt and copper acetates in the concentration from 1 to 5% (wt.) improves physical-mechanical properties of polyethylene composites. After the action of UV exposure and biological factors of soil during 120 days the tensile strength of composites containing 5% (wt.) of ZnAc2, CoAc2 and CuAc2 is reduced to 42.5%, 70% and 23%, respectively. The composition and intensity of the volatile products degradation of composites were characterized by pyrolysis mass spectrometry. The temperature dependences of the total ion current of volatile products release for the thermal degradation of polyethylene with functional additives show the changes of intensity depending on the temperature and the nature of cations. The changes in intensities of the mass numbers suggest that the additives of metal-containing compounds cause the structural changes in polyethylene and reduce its strength under the action of destructive factors.

51-55

Authors: A.L. Kontsevoi, S.A. Kontsevoi, L.V. Vasenko

A new method for the calculation of equilibrium gas compositions is developed, which takes into account the quantity and composition of a coal subjected to continuous steam-oxygen-air gasification. Only three reactions have been selected from numerous ones as follows 2СО  С + СО2, СО2 + Н2  СО + Н2О and С + 2Н2  СН4; those reactions adequately describe the various methods of gasification. The system of three equations has been derived on the basis of equilibrium constants, values of initial parameters concentration, pressure and temperature of the coal gasification. A solution of the obtained system by means of MathCAD software gives the equilibrium conversion ratio for the above mentioned reactions as follows: x, y and z for CO, CO2 and H2, respectively; this allows determining the equilibrium composition of the generator gas. The feature of the proposed mathematical model is the possibility to make a mass balance of the process. The effects of temperature and excess water vapor on the equilibrium composition of the gasification components have been studied. The multiple calculations allowed identifying the start temperature of the coal full transformation for various mixtures of oxidants. The investigation of the gasification parameters has been performed for the pressure of 2 MPa and the volume ratios of the gas mixture of N2/O2 = 1 and Н2О/O2 = 1; it has been revealed that the complete coal gasification is possible at the temperature more than 1300 C for this gas mixture. For the gas mixtures with the volume ratios of N2/O2 = 1 and Н2О/O2 = 2, the complete gasification is possible at the temperature of more than 865 C.

62-66

Authors: Z.C. Salayeva, R.M Mustafayeva, H.G Isaev, Н.A Mammadaliyev

The results of study on development of multifunctional catalyst based on natural clays are presented in this contribution. The method of catalyst preparation is described, the method contains the trituration of the activated clays into a powder, the subsequent addition of the binder material (raw clay), the mixing of the clays with salt solution of active components and the final heat treatment of catalyst. The favorable conditions of these steps are described in the article. In order to select the optimal concentrations of the active components, the catalysts, which are based on natural clays with different contents of iron and molybdenum, were tested in hydrogenation recycling of aromatic concentrates of liquid pyrolysis products. The catalyst based on activated clay of Khanlar deposits (a so-called "Khanlarit" and raw clay of Dash-Salakhly deposits (Azerbaijan)) was tested in long-term experiment for 200 hours in the conditions of hydrogenation recycling technical benzene–toluene–xylene (BTK) fraction of pyrocondensate. The catalyst shows high catalytic activity and stability and after oxidative regeneration recovers its initial activity. The compositions of the used clays are given in the article. The developed catalyst can be used in thermal catalytic hydrogenation recycling process of liquid pyrolysis products for the industrial production of benzene. The influence of the main parameters on the pyrolysis was studied with the purpose of the selection of the optimal conditions for thermal catalytic hydrogenation process. A technological scheme of the benzene production process of thermal catalytic hydrogenation recycling of aromatic concentrates is presented in the paper.

73-75

Authors: I.L. Plaksienko, N.V. Nikolenko

This communication is devoted to the 85th anniversary of the birthday of Professor V.I. Suprunovich who worked more than 50 years at the Ukrainian State University of Chemical Technology. Victoria Suprunovich is a well-known analyst. She has made a great contribution to the development of electrochemical methods for the analysis of the 47 metal ions of 29 chemical elements. The developed methods were based on complexation reactions between the metal ions and S- and N-containing organic reagents such as 8-mercaptoquinoline, tetra ethyl ammonium naftalin ditiokarboksylat, dalzin, unitiol, vismutol et al. The communication describes the main stages of the life, educational and research activities of V.I. Suprunovich. The main scientific achievements of Professor V.I. Suprunovich and her scientific school were considered. Her scientific heritage includes more than 300 scientific articles and several monographs and tutorials. More than 60 algorithms of methods for the analysis of a variety of industrial and natural materials have been developed, including rapid and selective methods for determining the individual components of the combinations of metals in various oxidation states, a comprehensive analysis of a variety of analytical facilities. By means of X-ray analysis, thermography, polarographic and spectral methods, the identification of the chemical and analytical properties of more than 100 new coordination compounds of 8-mercaptoquinoline has been performed. Prof. Suprunovich proposed new analytical forms to analyze steels, alloys, coatings, solders, enamel frit, ores, fireclay refractory, and jewelry alloys. Under the leadership of Prof. V.I. Suprunovich, a scientific school has been created and fifteen PhD theses have been defended. For active teaching and fruitful scientific works, Professor V.I. Suprunovich was repeatedly presented with diplomas and honorable distinctions, including the medal "For Valorous Work". The researches in the field of electrochemical analysis methods are still continued at the Analytical Chemistry Department of the Ukrainian State University of Chemical Technology. The staff of the Department remembers and reveres Prof. V.I. Suprunovich memory.

9-15

Authors: V.V. Matveyev

The changes in potentiodynamic curves of n-benzoquinone and naphthoquinone as a function of the total amount of active substance deposited on the electrode have been studied by means of thin-layer electrochemical cell allowing visual control of the processes occurring on electrode surface. If the amount of reagent is smaller than it can be completely dissolved in the electrolyte, "reversible" peaks are observed in anodic and cathodic curves. When the amount of the reactant is higher and the part of the active substance is crystallized, "irreversible" maximums appear in the potentiodynamic curves. The capacity of these peaks increases. "Reversible" peaks remain but their amplitude and the corresponding capacity do not increase. Direct observation of the processes on the electrode revealed that the electrochemical process of the reduction of the quinone crystals with the formation of hydroquinone and the reverse process proceed according to the following mechanism: dissolving; then, electrochemical reaction, and, finally, crystallization, i.e. in two stages. The product of the first stage of the reaction is a crystalline quinhydrone (naphthoquinhydrone). In the second stage, these crystals are dissolving. There is "irreversible" current maximum for each stage of recrystallization. Cycling is accompanied by transferring small crystals from an electrode zone and their subsequent enlargement which results in the loss of capacity.

21-25

Authors: A.V. Slipkan, D.E. Kytovа, A.V. Shtemenko

We investigated the process of intercalation of dirhenium(III) complexes of the trans-configuration with the general formula trans-Re2(RCOO)2Cl4 into zirconium phosphate (ZrP), using 7.6 Å – ZrP layered inorganic nanomaterial as a precursor. To determine the most effective parameters of intercalation, complex/ZrP systems at a ratio of 1:5 and 1:30 were used, and the solvent has been determined. X-ray powder diffraction (XRPD) and UV-Vis spectroscopy were applied to confirm the presence of dirhenium(III) complexes between the layers of ZrP. XRPD data indicate that a new phase with an expanded interlayer distance of 13.39 – 11.5 Å was obtained and the efficiency of the incorporation of dirhenium(III) compound increases with an increase of its amount which was confirmed by UV-Vis spectroscopy. During the intercalation process, the change in the UV-vis spectra of rhenium(III) complex of trans-configuration was observed. For the system dirhenium(III) complex/ZrP in a ratio of 1:5, disappearance of maximum at 12500 cm-1 and the shift of the absorption bands from 16129 cm-1 to 16393 cm-1 were observed indicating the formation of cis-structure type of dirhenium(III) complex. Thus, these results open new perspectives for the use of dirhenium(III) compounds as biologically active substances.

31-35

Authors: D.A. Shaiderov, A.A. Kityk, V.S. Protsenko, F.I. Danilov, U. Pramod Kumar, C. Joseph Kennady

The paper reports the results of our experimental study on the effect of water addition to a nickel plating bath containing deep eutectic solvent Ethaline (i.e. eutectic mixture of choline chloride and ethylene glycol) and nickel chloride upon some physicochemical properties of liquid mixtures and nickel electrodeposition process in these systems. The introduction of extra water is shown to promote a substantial increase in conductivity and a decrease in viscosity which reach the values typical of "common" aqueous nickel baths. The liquid mixtures containing choline chloride, ethylene glycol, nickel chloride and water (in the molar ratio of 1:2:1:x, respectively, where x = 6, 9, 12, 15 or 18) allow electrodepositing uniform and well adherent nickel coatings with the current efficiency of 90 to 100% at current density of ~4 A/dm2 and temperature of 303 K. Nickel coatings obtained from the investigated ionic liquids have a nanocrystalline structure with an average crystallite size of 5 to 7.5 nm. The microhardness of the nickel electrodeposits increases when increasing the water content in the system and is in the range from 420 kg/mm2 (at x = 6) to 503 kg/mm2 (at x = 18).

40-46

Authors: O. Shmychkova, T. Luk'yanenko, A. Velichenko

It has been revealed that Ni2+ ions are adsorbed on the lead dioxide surface. Their adsorption is described by the Langmuir isotherm and according to the value of the interaction energy has a weak specific character. It is shown that the addition of Ni2+ ions to the deposition electrolyte leads to a slight inhibition of the PbO2 formation due to blocking of active centers by the ionic additive. This reduces the currents both on the cyclic voltammogram and in the partial polarization curve of the formation of lead dioxide. In this case, the mechanism is not changed and is described by the traditional four-step scheme, according to which the formation of PbO2 proceeds in four stages, two of which are electrochemical steps of electron transfer, and the other two are chemical stages of the formation and decay of soluble intermediates (trivalent lead and tetravalent lead). The first step is the first electron transfer with the formation of oxygen-containing particles such as ОНads on the electrode surface, the particles being formed by the anode ionization of water. Then, in the subsequent chemical step, these particles react with lead ions with the formation of a mobile oxygen-containing intermediate of Pb (III) such as Pb(OH)2+ at the electrode surface, the intermediate is subsequently oxidized with the second electron transfer. As a result of this reaction, soluble tetravalent lead intermediates (such as Pb(OH)22+) are formed, disintegrating in the last step with the formation of lead dioxide.

53-60

Authors: Yu.M. Danchenko, Yu.V. Popov, E.S. Barabash

Acid-base properties of the surface of polymineral oxides are studied by means of pKa spectrophotometry method. The heat treatment results in an increase in the total concentration of surface Brønsted active centres by 1.5-3 times and a considerable increase in the number of the centres with acid properties. An extent of acidity increase is directly proportional to the content of SiO2 in the structure of filler. Experimental results and calculations reveal that the increase in polymeric layer density is due to the effect of the surface acid-base active centres when the filling of epoxy amine compositions occurs. We suggest using the indicator of the acid-base relationship (Q) as a criterion for the estimation of the influence of filler surface on the polymer structure in the interphase layer. The indicator allows characterizing a surface as neutral, acid or basic one when Q ≈ 1, Q > 1 or Q < 1, respectively. In order to obtain the composites with improved strength properties, one should use the fillers with subacid or subbasic surface properties (Q = 0,5-4) and a high total concentration of the active centres (more than 100∙10-14 cm-2). The application of fillers with a neutral surface (Q ≈ 1) leads to the improvement in the indicator of composites abrasion and practically has no effect on other properties. The fireproof properties of the filled epoxy composites depend on both the ratio between surface acid-base Brønsted centres of the filler and their acid strength рКа.

64-70

Authors: N.V. Nikolenko, I.S. Samchileyev, R.I. Zakharov, V.L. Kovalenko

The solubility diagrams for oxygen compounds of the system Fe(III)–Mo(VI) were calculated in the pH range of 0 to 14. When calculating the solubility of precipitates, the hydrolysis reactions of iron(III) and molybdate ions, protonation of molecules H2MoO4 and the complexation between Fe(III) and hydroxide ions were taken into account. It has been established that the highest solubility of Fe2(MoO4)3 can be provided in alkaline solutions, whereas the most stable solid phase is Fe(OH)3 at pH  7 and the precipitate of H2МоО4 is completely dissolved. The contamination of the end product (i.e. molybdenum salt) with iron impurities is possible at pH > 13 due to an increase in the solubility of Fe(OH)3. On the basis of thermodynamic and kinetic analysis, it was concluded that the best reagent for optimum leaching of molybdenum from molybdenum- and iron-containing raw materials is concentrated ammonia solution. It is concluded that the chemical model of the spent catalyst treatment is included three reactions: ammonia decomposition of the spent catalyst, the dehydration of iron hydroxide and precipitation of ammonium molybdate in the form of ammonium heptamolybdate. The main stages and the technological model of the spent catalyst treatment by the ammonia leaching method were considered to obtain the ammonium heptamolybdate and iron oxide.

76-81

Authors: D.А. Oreshkin, Yu.R. Kolesnik, O.V. Chervakov

The durability and performance of glass composites depend on their water absorption. This paper reports the process of surface protection of composite reinforcement by organosiloxane solution with the purpose of reducing its water absorption and increasing chemical and frost resistance. It was established that the water absorption of glass composites increases significantly during cyclic water saturation-drying as well as during boiling in water or in base model of concrete pore liquid, this is due to the destruction and hydrolysis of the components. This phenomenon is almost eliminated after the surface protective treatment of samples with oligomeric organosiloxane solution. The examination of IR spectra of some model systems (i.e. oligomeric dimethylsiloxane, polyester resin and fiberglass) allows suggesting the interaction of organosiloxane molecules with glass surface by terminal hydroxyl groups. On the basis of experimental data, we revealed that the surface treatment of glass composite samples with oligomeric organosiloxane solution reduces significantly their water absorption during cyclic, temperature and alkali exposure, which allows recommending glass composite reinforcement for the application in cement-concrete structures.

10-13

Authors: N.M. Velikonskaya, V.V. Velichko, E.A. Lominoga

In this paper the interaction of scandium(III) ions with salicyl fluorone in the presence of cationic surfactants, nonionic ethoxylated alcohols and their anionic derivatives was studied by spectrophotometric method. It was stated that the optimum pH region is from 2.5 to 7.0. The composition of the complexes Sc–R formed in the presence of surfactants was determined. The results showed that the ratio of Sc:R = 1:2 in the presence of the surfactants differed from that Sc:R = 1:1 which was established in case of the stabilization of the complex with gelatin. In the presence of the surfactant the solution was stable for 20 hours or more. The instability constants have been calculated. It was shown that the instability constants weakly depend on the length of the alkyl radical of surfactant; however, decreasing the degree of ethoxylation results in a substantial increase in the molar extinction coefficient. We determined the concentrations region where Beer's law holds valid (1.410-7–17.110-7 mol/L) and the molar ratios of light absorption of scandium salicyl fluoronats. The use of surfactants resulted in an increase in molar extinction coefficient of 3.5 – 4 times, thus improving analytical possibilities of their application.

21-25

Authors: A.A. Golichenko, S.Y. Treyak, A.V. Shtemenko

The antiradical activity of cis-tetraсhlorodi-μ-carboxylate of dirhenium(III) in various solvents was studied by electron spectroscopy. Carried investigations of interaction of 1,3,5-triphenilverdazile radical with Re2(CH3COO)2Cl42DMSO as an example in 1,2-dichloroethane showed that dirhenium(III) complex compounds with the saturated aliphatic acids are able to neutralize multiple excess of free radicals passing through the step of formation of the intermediate state "complex of rhenium(III) – radical". The use of similar Re26 + derivatives with ligands which contain π-bond (ferulic, indolile-3-acetic acid) causes stabilization of transition state "complex of rhenium(III) – radical" structure. It is shown that the rate of free radical destruction depends on the nature of the solvent. Solvating ability of methanol causes decrease of stability of intermediate state "complex of rhenium(III) – radical" and increase of rate of radical destruction.

32-35

Authors: D.O. Kolomieitsev, S.A. Varenichenko, V.O. Astakhina, V.I. Markov, S.I. Kovalenko, O.V. Kharchenko

Sulphur-containing fused pyrimidines, in particular thienopyrimidines, exhibit wide spectrum of biological activities which stimulates investigation of synthesis and reactions of these compounds. Our previous studies on new series of R1,R2-thieno [2,3-d] pyrimidine-4(3H)-one, thio(seleno)ne derivatives showed that some of obtained compounds have good antimicrobial activity. Another derivative of benzothieno [2,3-d] pyrimidine, 4-hydrazino-5,6,7,8-tetrahydro [1] benzothieno [2,3-d] pyrimidine 3, contains several reactive centers and the heterocyclization reactions can occur in different directions depending on the nature of cyclizing reagents. This paper reports the result of interaction of different dicarboxylic acid anhydrides (maleic, phthalic and endic anhydrides) with the multifunctional compound 4-hydrazino-5,6,7,8-tetrahydro [1] benzothieno [2,3-d] pyrimidine 3 to form novel heterocyclic compounds. The intermediate compounds of cyclization have been identified. The reaction was stated to occur either with intramolecular nucleophilic addition (for maleic anhydride) or with the formation of imid derivatives (for phthalic and m-nitrophthalic anhydrides) depending on the nature of dicarboxylic acid anhydride. The interaction of hydrazine 3 with endic anhydride occurs in one step. The new compounds were characterized by 1H NMR spectroscopy, mass spectrometry and elemental analysis.

45-51

Authors: R.V. Smotraiev, Ye.A. Manidina

The absorption kinetics of sulfur oxide(IV) by solutions of iron(II) and iron(III) salts was investigated. It was found that the absorption of sulfur oxide(IV) by solutions of iron(II) and iron(III) salts in the diffusion region proceeds in two stages: the first stage occurs by the absorption mechanism with a rapid irreversible reaction in the liquid phase; the second stage occurs via the absorption mechanism with a reversible reaction in the liquid phase. The main kinetic characteristics of the process were determined: the rate constants of absorption process for both stages; apparent activation energy and pre-exponential factors for each stage as follows: E1 = 14.26 kJ mol-1, K01 = 0.05 s-1, E2 = 9.01 kJ mol-1, and K02 = 0.01 s-1, respectively. The temperature coefficient of absorption rates is in the range of 1.04 to 1.3. The values of rate constants at the first stage of the absorption process are 1.2 to 1.7 times more than the rate constants on the second stage of the absorption process. The absorption rate of sulfur oxide(IV) by solutions of iron(II) and iron(III) salts significantly depends on the sparging mode. Thus, it is expedient to carry out the absorption process in the Reynolds number range of 50 to 100, because at lower Reynolds numbers the rate constant is significantly reduced, and for higher values there is a significant spray entrainment. The equation of the rate constant dependence for the absorption of sulfur oxide(IV) by solutions of iron(II) and iron(III) salt on the temperature and the gas-phase flow mode was determined.

57-61

Authors: D.G. Zublev, V.D. Barsky

We investigated the influence of both the air supply to decarbonization and the value of disclosure recirculation windows on the recirculation of combustion products in the verticals of coke oven battery located in the middle of the heating wall. The investigation was performed in a production environment. All measurements were carried out at the recirculation windows opened by 100% and 50%. The contents of oxygen and carbon monoxide in the samples of the combustion products taken from the recirculation windows from the vertical downward flow exceed the content of these gases in the samples collected from vertical upward flow. This indicates the presence of a so-called "short circuits" in the heating channels: instead of feeding the combustion products from the vertical downward flow in the vertical upward flow of coke oven gas and air from the vertical upward flow through the recirculation box arrives in a vertical downward flow. The presence of "short-circuit" is also confirmed by measurements of pressure drop. In all cases pressure was higher near the recirculation windows in the vertical of the upstream than in the vertical of the downstream, which is consistent with the results of analysis of the combustion products composition.

68-73

Authors: I.M. Kas'yanenko, V.Yu. Kramarenko

The influence of pigment volume concentration (PVC) and pre-treatment conditions on the vapor and liquid water permeability of a coatings based on aqueous acrylic dispersion Acronal 290D has been studied by international standard methods. These parameters show that water is penetrated through coatings more quickly with increasing PVC. The Nielsen's model for the permeability of the systems containing porous aggregates of filler particles has been used and the fitting parameters were determined. Based on a very sharp PVC dependence and very low values of exponent parameters, it can be concluded that filling of water-based coatings facilitates water migration similar to the channel type diffusion. Increasing of pre-treatment cycles number results in the reduction of permeability that can be related to the enhanced efficiency of coalescence process due to higher temperature conditions at drying of coatings. The PVC effect on the class of coatings in coordinates of the Kunzel's diagram has been also demonstrated.

79-80

Authors: A.O. Omel'chuk, O.A. Pivovarov, A.V. Kravchenko, F.I. Danilov, A.V. Shtemenko

Doctor of Science, Academician of National Academy of Sciences of Ukraine, Professor Volkov S.V. passed away on March 9, 2016. The article highlights the path of Academician Volkov S.V. in science and his contribution to modern inorganic chemistry.

9-13

Authors: A.Yu. Karnina, A.O. Gyrenko, O.P. Mysov

The kinetics of ammonium tetravanadate(IV) thermolysis is investigated in the paper, this compound being the precursor for obtaining nanodispersed vanadium dioxide. On the basis of derivatographic analysis results, the values of reaction order, activation energy and pre-exponential factor are determined which are equal to n = 1, E = 60.0±4.7 kJ/mole, and k0 = 748.3±3.8 s-1, respectively. To determine the reaction order, a method is used which has been suggested by Kissinger. The method is based on determining the maximum temperature of the investigated phenomenon and on the asymmetry of a differential-temperature curve that is assessed by planimetry. The stepwise character of the reaction is studied; the reaction starts at a temperature of 230±5 °С, then reaches a pick at 270±10 °С and is completed at 375±5 °С. The rate of samples heating during the analysis determines the final results; the optimal heating rate is about of 2.5 to 5 °С per minute. A model kinetic equation of ammonium tetravanadate(IV) thermolysis has been derived. The adequacy of this kinetic equation is confirmed by the fact that the two values of temperature coefficient coincide (γan = γexp), the former (γan) is calculated using Van't Hoff rule via the derived model kinetic equation, the later (γexp) is calculated based on the combined analysis of DTG curves within the temperature range of 250 to 320 °С.

20-24

Authors: N.Ya. Kuzmenko, S.N. Kuzmenko, O.V. Skrynnik

New organotitanium compounds of boron which contain butoxy and acrylate groups have been synthesized. The obtained compounds are reddish-brown liquids or solid substances at room-temperature; they are very soluble in aliphatic, aromatic and chlorinated hydrocarbons, lower aliphatic alcohols and ketones. The structure of the oligomeric [(alkoxy)(acrylate)titanate] boranes was confirmed by elemental and functional groups analysis, molecular mass spectrometry, IR and 1H NMR spectroscopies. The synthesis of such compounds by the acidolysis of tris[tri(butoxy)titanate] borane is accompanied by azeotropic distillation of a part of acrylic acid and n-butyl alcohol and by the side reaction of the formation of butyl acrylate and water. The interaction of water with butoxy groups of the end products results in occurring condensation processes; as a consequence, their molecule mass increases. The consumption of acrylic acid in the processes of butyl acrylate formation and its azeotropic distillation with n-butanol leads to the change of the stoichiometric ratio of the starting compounds; in addition, the degree of the substitution of butoxy groups with acrylate groups in the end products decreases compared with a computed value. The synthesized products simultaneously contain two complexing atoms (i.e. boron and titanium), reactive butoxy groups and unsaturated bonds of acrylate groups. This suggests that these compounds will be useful as active components (coupling agents) of polymer compounds to improve their properties.

29-34

Authors: T.L. Rakitskaya, A.S. Truba, А.A. Ennan

The phase composition of the samples of the solid component of welding aerosol (SCWA), which was obtained during welding of steel by means of UONI 13/55 electrode manufactured in Ukrainian, was studied by X-ray phase analysis and IR spectroscopy; the samples being both freshly prepared (FP) and modified by water treatment at 60 °C (M). It has been found that the both samples were polyphase and characterized by a high degree of crystallinity. Ten individual phases have been identified in the FP-SCWA composition as follows: magnetite (Fe3O4), manganochromite ((Mn, Fe)(Cr, V)2O4), goethite (Fe2O3), -Fe2O3H2O, manganese oxide (Mn3O4), calcium fluoride, potassium and sodium carbonates, potassium chromate (K2CrO4), magnesium silicate (MgSiO3), etc. The most intensive reflections are observed for mixed phases. Water treatment of the SCWA results in a disappearance of the reflections of water-soluble phases while the reflections of some individual phases become more intense. Taking into account characteristics of the reflection of (311) magnetite phase for FP-SCWA (2θ = 35.465, d = 2.529 Å) and M-SCWA (2θ = 35.418, d = 2.532 Å), the values of unit cell parameter for the cubic unite cells of spinel were estimated as follows: 8.3877 Å and 8.3976 Å for FP-SCWA and for M-SCWA, respectively. Using the well-known Scherrer equation, the sizes of magnetite nanoparticles were estimated, they were equal to 68.0 nm and 31.5 nm for FP-SCWA and M-SCWA, respectively. IR spectra for both samples are very complicated because of their phase inhomogeneity and structural features of certain phases. However, they contain the bands attributed to stretching and deformation vibrations of M–O and M–OH bonds which are typical of metal oxides and spinels. The results obtained by X-ray phase analysis and IR spectroscopy revealed some changes in the structure of certain phases as a result of hydrothermal treatment of the SCWA. Both FP-SCWA and M-SCWA demonstrate protective properties in respect to ozone at its concentration of 1.0 mg/m3; however, the values of the protection action time being different. The protection action time was 600 min for FP-SCWA, whereas it was 10 times lower for M-SCWA. The catalytic activity of the SCWAs depends on many factors, among them the phase composition, the ratio between phases which are catalytically active in the reaction of ozone decomposition, the unit cell parameter and the size of magnetite nanoparticles.

40-45

Authors: R.D. Apostolova, I.V. Kirsanova, E.M. Shembel'

Thin-layer molybdenum sulphides synthesized by electrolysis method can be used in lithium-ion micro batteries for miniature electronic devices such as smart cards, microsensors, etc. Molybdenum sulphides are deposited on the cathode from thin-layer aluminium which is known to the best anticorrosion constructional material in lithium-ion batteries. Mo-sulphide deposits with satisfactory adhesion to the substrate cannot be produced on smooth aluminium surface that leads to the deterioration of the discharge characteristics of Mo-sulphide lithium-ion batteries at long cycling. The modification of aluminium surface by zincate treatment was used in this work, it contribute to the strengthening of adhesion ability of the Al-substrate and the improvement of the electrochemical properties of Mo-sulphide lithium-ion batteries. It was established a positive effect of zincate treatment on the structure and discharge characteristics of synthesized materials with using X-ray phase analysis and discharge-charge cycling in galvanostatic mode. Mo2S3 sulphide was produced as monophase material on the modified surface of Al-substrate. According to the images of deposits surface obtained by means of atomic-force microscopy the deposit consists of agglomerates of nanometer size (200 to 250 nm). The reversible capacity of Mo2S3 in lithium-ion batteries achieves a value of 225 to 240 mA h g-1. The proposed method of preliminary zincate treatment of the aluminium substrate surface to electrochemically obtain thin-layer molybdenum sulphides for their further using in lithium-ion battery promotes allows increasing the relation of the active component mass to the metal substrate mass.

61-65

Authors: O.А. Kalinichenko, O. Banakx, T. Journot, P.A. Gay, L.A. Snizhko

The formation mechanism and some properties of coatings obtained from tricalcium phosphate solutions on titanium by anodic spark deposition were studied. The process was carried out in galvanostatic mode on unipolar pulses with frequency of 50 Hz at the current density of 400 Am-2 and voltage of 700 V. The propensity of coatings to dissolution in biologically active environments (SBF-test) was assessed by measurement of thickness, X-ray and elemental analysis data obtained before and after testing. It has been established that the basic components of coatings are titanium, titanium dioxide in anatase form, as well as calcium phosphate compounds, such as Ca3(PO4)2, CaTi4(PO4)6, and Ca(PO3)2. Ca/P atomic ratio of 0.35 to 0.45 weekly depended on the concentration of electrolyte and time of electrolysis in the range of 3 to 15 min. After a two weeks' endurance in SBF, Ca/P ratio declined on average by 20%, which testifies to the bioresorptive properties of obtained coatings. At the same time, the thickness of the film and content of titanium have increased, which may indicate the accumulation of titanium dissolution products in sublayer of the coatings.

72-77

Authors: A.Yu. Poloz, Yu.R. Ebich, N.R. Prokopchuk, R.M. Dolinskaya, V.V. Mozgalev

The influence of oligomeric rubbers with reactive groups, such as carboxylic, hydroxyl, epoxy, and acylhydrazone ones, which can interact with epoxy groups of the ED-20 resin matrix, on the properties of the epoxy compositions cured by polyethylenepolyamine was evaluated. The investigated oligomeric rubbers participate in forming the cross-linked structure of epoxy compositions. When oligomeric rubbers have been added in the epoxy matrix, an increase in the energy of deformation was observed which is caused by the presence of flexible fragments of three-dimensional network due to the incorporation of rubbers molecules. The contribution of energies of elastic and viscous deformations to the total energy of deformation was determined at abrasive damage of epoxy compositions at different angles of attack of the abrasive.