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

6-16

Authors: O.A. Brazhko, A.S. Yevlash, M.P. Zavgorodnii, M.M. Kornet, O.O. Brazhko, A.V. Lagron

At the present stage of the development of organic and bioorganic chemistry, several basic approaches to the synthesis of pyrrolo[1,2-a]quinolines are known. These compounds are of interest to the researches primarily as bioregulators with a wide spectrum of biological activity. This review is an attempt to systematize and generalize literary data relating to the chemistry of pyrrolo[1,2-a]quinoline and its derivatives as important synthetic substrates and precursors for the design of biologically active substances. The main approaches to the synthesis of these compounds, consisting in various preparative methods for constructing a tricyclic base of pyrrolo[1,2-a]quinolone, were considered. The search for biologically active substances of this series is important and has a practical and theoretical significance.

24-30

Authors: V.A. Vekshyn, E.R. Grabovetskaya, L.P. Abramova

The method of the designing of industrial reactors with metal cellular catalysts is considered in the article. The proposed catalysts can be used for the low-temperature purification of exhaust gases from nitrogen oxides using ammonia. The advantages of catalytic blocks are shown in comparison with the catalysts AVС-10 that is widely used in industry. The procedures of physicochemical study and analytical control are developed. Based on laboratory tests, the sizes and structure of the proposed reactors are determined. Required amount of catalyst in the form of metal cellular blocks is determined for two types of reactors: with rectangular and circular cross-sections. The length of catalytic units is calculated and production technology is proposed. Hydrodynamic calculations demonstrate that block catalysts have lower flow resistance that the granulated ones. The reactors of circular cross-section need catalytic units of smaller volume than rectangular ones; however, the latter have a lower resistance to gas flow. The study shows that the metal cellular catalytic blocks would allow avoiding the use of additional compressors for excessive pressure to purge gases through the catalyst bed, which should reduce economic costs, and, ultimately, reduce the cost of the product.

39-46

Authors: D. Girenko, O. Shmychkova, A. Velichenko

The main features of the processes occurring during the oxidation of chloride ions on the platinum surface were investigated as well as the catalytic activity and selectivity of platinum in the anodic synthesis of hypochlorite were determined. It was assumed that the oxidation of chloride ions on the platinum surface occurs with the participation of particles like OHads or Oads, which are active centers on the surface, according to the mechanisms of chlorine evolution described in literature. In addition, it was taken into consideration that polarization at high anodic potentials decreases the degree of surface filling with labile and simultaneously increases the degree of surface filling with inert particles. The obtained results showed that the formation of chlorine and hypochlorite proceeds with the participation of labile oxygen-containing particles. It was shown that the main three parallel processes are observed during the electrolysis of NaCl as follows: (i) the oxidation of Cl– to hypochlorite, (ii) the formation of chlorate, and (iii) the oxygen evolution reaction. On a pre-reduced surface, the current efficiency of hypochlorite reaches 90% and the process proceeds at polarizations lower by 400–450 mV in comparison to process occurred on an oxidized surface. Under these conditions, chlorates are practically not formed. However, the reduced surface is gradually oxidized in the course of electrolysis process. Therefore, the ratio of active sites at which Cl– oxidation occurs is declined. It was established that weakly bounded (labile) particles take part in the formation of hypochlorite. On the passive surface, the oxidation of Cl– even in 1–2 M NaCl solutions occurs at the limiting current, the value of which is determined by the fraction of active surface centers. Comparison of the values of the limiting currents on the active and passive surfaces allows us to conclude that the ratio of the active centers of the latter does not exceed 5–10%. It was established that the surface of platinum is easily activated during short-term cathodic polarization in the region of hydrogen evolution.

53-59

Authors: L.M. Grishchenko, N.S. Novychenko, I.P. Matushko, O.V. Mischanchuk, V.E. Diyuk

Active low-temperature heterogeneous catalysts of acid-base processes based on fruit-stone activated carbon were prepared in this work. Thermodesorption properties of the samples were studied. Depending on the modification method, one can obtain catalytic materials containing 1.20–1.45 mmol g–1 of surface acidic groups. The prepared samples showed a rather high thermal stability: the decomposition of phosphorus-tungsten acid on the surface of activated carbon occurred at the temperatures of above 600С. It was shown that the modification of the surface of activated carbon by phosphorus-tungsten acid led to the oxidation of the latter, especially at high temperatures; this was confirmed by an increase in the intensity and forms of carbon monoxide evolution in the thermodesorption spectra. The catalytic properties of the synthesized samples were investigated in the reaction of dehydration of isopropyl, ethyl and methyl alcohols in a gas phase. The catalytic activity of modified activated carbon depended on the concentration of acidic centers and the preliminary treatment of the surface of carbon. The temperatures of the maximum conversion of alcohols to the reaction products on the prepared catalysts were stated to be 140–155C, 160–180C and 180–255C for isopropanol, ethanol and methanol, respectively. Preliminary oxidation by nitric acid resulted in an increase in the catalytic activity towards the dehydration of all three alcohols, the temperatures of the course of dehydration reactions diminished by 10–20C. Preliminary oxidation by hydrogen peroxide led to a decrease in the activity of the prepared samples, the temperatures of the reaction of dehydration increased by 5–55C.

69-73

Authors: Ts.I. Dimitrov, Ts.H. Ibreva, А.V. Zaichuk, I.G. Маrkovska, А.А. Amelina, E.V. Каrasik

The synthesis of ferrum-willemite ceramic pigments in the system xFeO(2–x)ZnOSiO2 (where x=0.125–1.00) was investigated in this work. The results of colorimetric measurements (in the system CIEL*a*b*) showed that the concentration of iron(II) oxide in the composition of 0.25 mol is sufficient for preparation of ceramic pigments of red-brown color. An increase in the content of iron(II) oxide in the composition of ceramic pigments from 0.125 to 0.25 mol causes the growth of values of color coordinates а* (up to +26.68) and b* (up to +36.73) as well as lightness L* (up to 48.51). A further increase in the concentration of FeO in pigments to 1.0 mol results in a decrease in the amount of red color: the value of red color coordinate а* falls to +21,87. An effective role of hydrate of silicon(IV) oxide introduced as a quartz-containing component of experimental pigments is also shown. It allows reducing the temperature of their synthesis to 900–1000С. Moreover, the growth of the firing temperature from 900 to 1000С leads to a slight increase in the amount of red color of the developed red-brown pigments (value of color coordinate а* increases from +25.38 to +26.68). By means of the methods of X-ray phase analysis and electron paramagnetic resonance, it was found that willemite solid solution and spinel (zinc ferrite) act as a carrier of color in these ceramic pigments. Formation of the above crystal phases is completed already at the firing temperature of 1000С. The synthesized pigments can be successfully used for coloring of glaze coatings on ceramics as well as glass-enamel coatings for metals.

83-91

Authors: T.A. Karavayev, V.A. Osyka, V.O. Komakha, N.V. Kaluga, V.V. Tkachuk, O.O. Sikorskyi

The article presents the results of the IR-spectroscopic study of the processes of chemical interaction in the system mineral filler–modifier–binder, which can occur in the production of water-dispersion paints and affect the operational properties of the obtained coatings. The investigated model systems included mineral fillers (chalk as a carbonate filler for norplasts (designated as CFN) or kaolin from Prosianivske deposit (designated as KC)), modifiers (sodium salt of polyacrylic acid as a dispersant (designated as Axilat 32S) and potassium methyl silicone as a water repellent (designated as GKZh-11k)), and binders (aqueous dispersion of styrene-acrylic copolymer (designated as Ucar DL 450) or organosilicon polymer (designated as IE-2404)). The analysis of the obtained IR-spectra showed the possibility of the interactions in the following systems: Ucar DL 450+Axilat 32S involving C=C bonds and functional groups of OH, Ucar DL 450+GKZh-11k with the participation of OH, Si–H and C=C groups, and Axilat 32S+GKZh-11k via OH groups. A partial chemical interaction with the participation of C=O groups of the filler is possible in the system CFN+Axilat 32S. The replacement of Axilat 32S by potassium methyl silicone is associated with the chemical interaction with the chalk surface by means of adsorbed water and the C=O groups. After washing with water, this feature remains which allows predicting the formation of a surface layer of potassium methyl silicon molecules on the particles of CFN that provides its hydrophobization. The presence of interaction processes is also detected in the system KC-1+Ucar DL 450. This is evidenced by a decrease in the intensity of the first group of absorption bands by 20–25% and the appearance of the absorption band of the C–H bond. The system KC-1+IE-2404 is characterized by the interaction processes with the participation of the OH groups on the kaolin surface; the generated bonds show a hydrolytic stability.

99-106

Authors: T.P. Kovalenko, V.O. Serdiuk, V.B. Vostres, H.F. Matiko

This paper reports a kinetic investigation into the emulsion (co)polymerization of decyl meth- and decyl acrylate with methyl acrylate for the first time. The obtained results are used to prepare copolymers based on the products of the emulsion (co)polymerization. It is determined that decyl methacrylate does not homopolymerize with the formation of emulsions regardless of the nature of an emulsifier, its solubility and initiator structure. Moreover, they reduce the rate of copolymerization with methyl acrylate. The deceleration of the copolymerization in the presence of long-chain monomers is related to the a low activity of decyl (meth)acrylate as compared with methyl acrylate. The colloid-chemical and physicochemical properties of the synthesized dispersions are investigated. The position of the maximum of the dependences of viscosity and surface tension on the polymer composition coincides with the smallest particle sizes of the dispersion; hence, the alterations in the viscosity and surface tension of the dispersion are associated with the variations in particle sizes, which results in the changes in the interface surface area. The molecular weight distribution of emulsion copolymers is studied by a turbidimetric titration technique. The absorption of water, the strength and specific elongation of the (co)polymer films are determined by tension testing. Diffusion coefficients are calculated according to the first section of the water absorption curve; the obtained values show the deceleration of the rate of the water absorption by the copolymer film as compared with the polymethyl-acrylate films. The tensile strength of the poly(methyl acrylate-co-decyl acrylate) films is less than that of the poly(methyl acrylate-co-decyl methacrylate) ones, which corresponds with the well-known facts concerning the influence of a methyl substituent in an -position on the polymer properties. The addition of hydrophobic co-monomers, decyl meth- and decyl acrylate, to the structure of macromolecules with methyl acrylate strongly affects the properties of the dispersion and derived films, which is connected with the significant structural transformations of macromolecules in the dispersions and films.

113-120

Authors: O.A. Kostyk, O.H. Budishevska, V.B. Vostres, Z.Y. Nadashkevych, S.A. Voronov

This article presents a simplified method for the preparation of cationic starches with a different degree of substitution using triethylamine and epichlorohydrin as starting materials. The optimal conditions for a starch cationation by a semi-dry method have been determined. The cationic starch with quaternary ammonium cation groups was prepared by the interaction of an aminating reagent with corn starch in the presence of sodium hydroxide. The aminating reagent, 3-chloro-2-hydroxypropyltriethylammonium chloride, was synthesized by the one-pot interaction between triethylamine and HCl followed by the reaction with epichlorohydrin in the presence of cetyltrimethylammonium bromide as a catalyst. The cationic starches were fabricated with the degree of substitution of hydrogen atoms in starch hydroxy groups equal to 0.02–0.45. The effects of molar ratios of sodium hydroxide to the aminating reagent and the aminating reagent to starch (with respect to a D-glucopyranose unit) in the initial reaction mixture on the degree of substitution were investigated. It was shown that the cationic starch with the highest degree of substitution was formed at an optimal starting molar ratio of sodium hydroxide to the aminating reagent that is equal to 1.2–2.0. An increase in the molar ratio of aminating reagent to starch significantly increases the degree of substitution when the content of sodium hydroxide is less than the optimal value. The reaction efficiency of the cationation of corn starch decreases with an increase in the molar ratio of aminating reagent to starch (in the test range of 1.0 to 6.0).

128-135

Authors: V.M. Moskalyk, O.G. Arkhypov, V.G. Sozontov, I.L. Kovalenko

The aim of this work was to study the influence of temperature and initial concentrations of the components of the system on both the equilibrium composition of the liquid phase in the mixture "nitrogen oxides–nitric acid–water" and the content of a final product in the production of liquid mixtures N2O3–N2O4. The obtained results allow determining the main parameters of the distillation of stratifying mixtures "nitrogen oxides–nitric acid–water" in the production of N2O3–N2O4 solutions and justifying the choice of the composition of the mixture that is used for distillation. Based on experimental data, we showed that the optimal mass ratio N2O4:H2O in the prioduction of liquid mixtures N2O3–N2O4 is equal to (3–8):1, which corresponds to equilibrium concentrations of HNO3 in a liquid phase of 65–70 wt.%. The influence of temperature on the content of HNO3 and H2O in the vapor phase above the solutions of the HNO3–H2O–nitrogen oxides was investigated. The temperature dependence of the NO content in the vapor phase was established at various contents of the initial components. It was suggested that the appearance of maxima in the dependence involved was due to the predominance of the processes of decomposition of nitrous acid and dissociation of N2O3 in the range of lower temperature, whereas a further increase in the temperature resulted in an increase in the vapor pressure of nitrogen oxide(IV) and a decrease in the concentration of NO. A mathematical dependence of the equilibrium concentration of nitric acid on the initial ratio N2O4:H2O, temperature and initial concentration of HNO3 was derived. The obtained equation allows determining the equilibrium mass concentration of nitric acid with a sufficient accuracy for the ranges of the initial mass ratio N2O4:H2 of 1:2 to 12:1, the temperatures of 293–353 K and the initial HNO3 concentrations of 40–68.4 wt.%.

144-148

Authors: P. Daniel Nixon, C. Joseph Kennady

Manganese-nickel oxide films were electrodeposited on a stainless steel plate substrate in a bath containing manganese sulfate, nickel chloride and a non-ionic surfactant. The structural, morphological and electrochemical properties of these films were investigated. The X-ray diffraction pattern revealed the grain size of the material and confirmed the presence of manganese oxide and nickel oxide in the films. The preparative parameters, such as potential window, scan rate, bath concentration and numbers of potential cycles, were optimized during potentiodynamic deposition. The cyclic voltammetry was used to study the reduction and oxidation mechanism during the electrodeposition process. The charge-discharge method was applied to study the capacitor property of the synthesized material.

157-163

Authors: L.K. Patrylak, O.P. Pertko, V.A. Povazshnyi, O.V. Melnychuk

Up-to-date fluid catalytic cracking catalysts for large-tonnage refining processes work under extremely hard conditions and need to have a high stability to the thermal and steam treatment. Therefore, the purpose of this work was to compare the effect of lanthanum and zirconium additives on the porous characteristics and catalytic activity of the microspherical cracking catalysts in fresh and steamed form that were synthesized based on the Ukrainian kaolin. The synthesized initial sample contained 30% Y zeolite that was transferred to the H-form before the modification by lanthanum and zirconium. The modification led to some decrease in BET surface and samples microporosity, which was substantially intensified after steaming. In the case of zirconium, such a decrease was less than for lanthanum. The effect of the catalysts modification on the vibrations of the structural components of the zeolite lattice was investigated by FTIR spectroscopy. The observed shifts of absorbance frequencies of the bond at 1070 cm–1, which correspond to the asymmetric vibrations of tetrahedra after corresponding modifications, indicated the isomorphic substitution of the aluminum atoms by zirconium ones. The steamed samples with the zirconium content of 6.5% demonstrated the highest conversion of cumene cracking (an increase by 20–30% as compared with the unmodified sample). Therefore, the modification of fluid catalytic cracking catalysts by zirconium affects both on the adsorption and on the catalytic properties of the steamed samples.

170-176

Authors: I.G. Radzievska, O.P. Melnyk, V.M. Pasichnyy, A.I. Marynin

When developing heterogeneous food systems that contain a liquid–liquid interface, surface-active substances (surfactants) are used to reduce the surface tension and promote the stability of the emulsions. Phosphatidylcholine is a common food additive, which is widely used in emulsion products. At the same time, the physical-chemical properties of phosphatidylcholine have not been fully investigated, and its surface-active properties are not known to date. This work reports the properties of the surface layer of phosphatidylcholine obtained by step extraction from the phosphatidic complex of chicken eggs, sunflower oil and soybean oil. Based on the calculated values of the limiting adsorption, the thickness of the adsorption layer and the surface area occupied by one molecule, the identity of the surface-active properties of the studied surfactants was shown when a water-in-oil type emulsion is formed, irrespective of the source of raw materials (animal and vegetable origins). NMR 31P spectroscopy method revealed that there was no significant difference in the group and fatty acid compositions of the studied samples (0.5%). The value of the hydrophilic-lipophilic balance of the phosphatidylcholine was stated to be 6.475; thus, it belongs to the amphoteric emulsifiers of water-in-oil type emulsions. The concentration of structural transformations was determined to be 0.3%; therefore, one can prepare stable oil-water emulsions without the use of additional co-emulsifiers. The obtained data may be used for the precise selection of the composition of multi-component stabilization compositions and effective control over the stability of the structured systems.

184-189

Authors: Y.D. Rublova, N.V. Amirulloeva, V.S. Protsenko, F.I. Danilov

Surface activity of sodium dodecylsulfate and micelle formation in solutions based on deep eutectic solvents ethaline and reline (eutectic mixtures of choline chloride with ethylene glycol and urea, respectively) were investigated. The isotherms of surface tension were treated using Langmuir model and the adsorption parameters at the interface "solution/air" were determined. The change in the nature of a solvent results in a decrease in the adsorption equilibrium constant in the following sequence: water>reline>ethaline>ethylene glycol, which is caused by the corresponding changes in the solvents polarity and intensity of hydrophobic interactions. The critical micelle concentration of sodium dodecylsulfate is equal to 3.5510–3 М and 2.1410–3 М in solutions based on ethaline and reline, respectively. These values are lower than that in an aqueous medium (8.1110–3 М). An increase in the content of water additive in deep eutectic solvents has only a marginal impact on the adsorption equilibrium constant, but leads to an increase in the critical micelle concentration.

197-204

Authors: O. Stashkiv, V. Vasylechko, G. Gryshchouk

The sorptive properties of the acid-modified Transcarpathian clinoptilolite towards Gd(III) under dynamic conditions were investigated. The sorption capacity of the clinoptilolite in H-form depends on the nature and concentration of acid-modifier. The most effective sorption of Gd(III) was observed when clinoptilolite was pretreated with 1 M H2SO4 solution. The sorption capacity of the H-form of Transcarpathian clinoptilolite towards Gd(III) significantly depends on the concentration of gadolinium salt, the pH of solution and the temperature of the preliminary calcination of the sorbent. The sorption capacity of H-clinoptilolite under optimal conditions (diameter of zeolite grains was 0.20–0.31 mm; flow rate of gadolinium(III) solution with concentration 0.5 µg/mL through sorbent was 5 mL/min; and pH 10.0) was 8.2 mg gadolinium per 1 g of acid-modified clinoptilolite. The H-clinoptilolite sorbs the Gd(III) trace amounts even in the presence of other common ions. The solutions of 1 M HCl and 1 M KCl acidified by a hydrochloric acid to pH 4.0 are the most effective desorbents of gadolinium(III) ions from H-clinoptilolite. The method for gadolinium trace amounts preconcentration from aqueous solutions in a solid phase extraction mode with a further determination of this rare earth element by a spectrophotometric method was developed. The detection limit of this method is 0.3 ng/mL, and the linearity was evaluated in the range of 1–200 ng/mL.

213-220

Authors: V.I. Sytar, I.M. Kuzyayev, K.M. Sukhyy, O.S. Kabat, E.A. Belyanovskaya

Experimental and theoretical studies in the field of development and modernization of gas-filled polymeric materials were analyzed. The foamed material structure was shown to be dependent on the nature and concentration of porogens. The choice of phenylone as a polymer matrix and magnesium carbonate as a gasifier was substantiated to develop heatproof foamed polymer compositions with increased strength properties. Thermal gravimetric analysis of the substances formed at the temperatures of phenylone transitions to the state of viscous flow with emission of gaseous products was performed. According to experimental results, magnesium carbonate (MgCO3) was chosen as a porogen that is decomposed during heating with the formation of carbon dioxide and magnesium oxide. The most intense gas production process proceeded at 590 K during 15–20 min. The high values of melt viscosity of aromatic polyamide phenylone considerably blocked pore formation in the bulk of a polymer. In order to decrease the viscosity of the melt composition, it was doped with 2–3 wt.% of oligodimethylsiloxane. The results of thermomechanical study revealed that magnesium oxide, which was formed when magnesium carbonate was decomposed, have a thermostabilizing effect on the polymer, which resulted in an increase in the glass transition temperature of phenylone. It was shown that the main characteristics of the developed materials (density, thermal conductivity, and specific heat capacity) were strongly affected by porogen concentration. The study of the surface morphology of the samples exhibited a highly dispersed structure in the polymer volume with pore size close to 100–300 m. Comparative analysis of foamed phenylone and commercial foamed plastics revealed that the maximal operational temperature was about 653 K for the materials developed in this work, whereas this parameter was close to 423 K for known foamed plastics. The developed material can be recommended to use for heat insulation in aircraft and aerospace industries.

228-235

Authors: Y.A. Titov, N.M. Belyavina, M.S. Slobodyanik, V.V. Chumak, O.I. Nakonechna

The conditions of isovalent substitution of lanthanum atoms for dysprosium atoms in A-positions of the SrLa2Sc2O7 two-slab perovskite-like structure of the SrLa2Sc2–xInxO7 type have been determined as follows: 0x1.60. Samples with x1.7 are multiphase and contain a number of additional phases, the main one being the phase with a cubic structure (а1.06 nm). Orthorhombic crystal structure (Fmmm space group) of the SrLa2–xDyxSc2O7 phases with the substitution degree of lanthanum atoms of 0.5, 1.0 and 1.5 was determined by the Rietveld method. The SrLa2–xDyxSc2O7 crystalline structure is based on two-dimensional (infinite in the XY plane) perovskite-like blocks, consisting of two slabs connected by vertices deformed ScO6 octahedra. Neighboring blocks are separated by a slab of A2O9 polyhedra (A2=Sr+Ln (x=0; 0.5 and 1.0) or Ln (x=1.5) in such a way that there are no direct Sc–O–Sc bonds between the octahedra of neighboring blocks. The blocks are connected through the O–A2–O bonds. Eight oxygen atoms of the A2O9 polyhedron belong to the same block as the A2 atoms, and the ninth oxygen atom belongs to the neighboring block. A1 atoms (A1=Sr+La (x=0, 0.5 and 1) or only Sr (x=1.5)) are located at 4b position in the intrablock voids of the SrLa2–xDyxSc2O7 slab perovskite-like structure and their coordination polyhedron is a deformed A1O12 cuboctahedron. It is established that isovalent substitution of lanthanum atoms by smaller dysprosium atoms leads to a gradual change in the distribution of strontium and lanthanides atoms in the interblock (8i) and intrablock (4b) positions of the SrLa2–xDyxSc2O7 structure: from partially ordered (x=0) to fully ordered (x=1.5). In this case, dysprosium atoms replace strontium atoms at the block boundary, and the decrease in the content of lanthanum atoms in the 4b intrablock position is compensated by the strontium atoms invasion. Analysis of the structural features of the SrLa2–xDyxSc2O7 phases showed that an increase in the degree of isovalent substitution of lanthanum atoms leads to a significant (more than twofold) increase in the deformation degree of the A2O9 interblock polyhedra and a decrease in the A2–O interblock length. Such structural changes, which result in a destabilization of the interblock "stitching", become one of the main destruction factors of the layered perovskite-like structure of the SrLa2–xDyxSc2O7 phases at x>1.6 and cause the absence of the SrDy2Sc2O7 scandate. The obtained data on the composition/structural features relations of the slab perovskite-like structure could be used for the purposeful regulation of the structure-sensitive properties of the SrLa2–xDyxSc2O7 type phases.

241-246

Authors: I.V. Fesych, S.A. Nedilko, N.I. Sabadash, O.G. Dziazko, T.A. Voitenko, O.V. Grabovska, M.A. Zelenko

Polymer composite with difference amount of polyvinyl alcohol (PVA) were synthesized using co-precipitation method. X-ray analysis showed the phase identity of the synthesized composite materials. The samples were indexed in hexagonal syngony (space group P63mc). It was found that the average crystallite size of ZnO is about 39 nm, while it is about 23 nm for ZnO/10%PVA. It was noted that the addition of polymer modifier agent played a vital role in controlling the growth of the crystal during the synthesis of ZnO-polymer composites. Unmodified ZnO had higher photocatalytic activity than the modified one. Thus, almost 100% decolorization of a Rhodamine B water solution was observed after 150 min, while only every tenth molecule of the dye was destroyed in the presence of the ZnO/30%PVA. The rate of photocatalytic degradation of organic molecules was significantly smaller in the presence of the oxide-polymer composite because adsorption layer of the PVA molecules on the surface of ZnO particles was formed. This significantly reduced the sorption of Rhodamine B from solution and increased its photostability. It was shown that the degradation efficiency decreased with increasing of the polymer modifier content in the samples. The obtained results have important technological importance since the synthesized composites can be used as UV filters and ingredients of sunscreens.

255-262

Authors: R.E. Khoma, V.N. Baumer, P.B. Antonenko, A.O. Snihach, V.V. Godovan, A.A. Ennan, R.M. Dlubovskii, V.V. Gelmboldt

Aminomethanesulfonic acid (Ia), and its N-methyl (IIa), N-n-propyl (IIIa), N-tert-butyl (IVa) derivatives were synthesized (IIIa has not been previously described) and characterized by means of X-ray diffraction analysis, IR spectroscopy, and mass spectrometry. Aminosulfonic acid 3a of zwitterionic structure crystallizes in the orthorhombic space group Iba2 with the following cell parameters: a=8.8405(6) Å, b=20.6348(12) Å, c=8.0433(7) Å, ===90, V=1467.27(18) Å3. The aqueous solutions of sodium salts (Ib–IVb) were prepared by reacting NaOH with the corresponding Ia–IVa acids in equimolar amounts. The toxicity of Ib–IVb was studied on 132 mice. The derivatives of aminomethanesulfonic acid belong to almost non-toxic compounds (V category of toxicity) following both intraperitoneal and oral administration in mice. According to the LD50 values, the compounds could be ranked in the following order: IIIb (2110 mg/kg)

268-274

Authors: G.N. Shabanova, A.N. Korohodska, S.V. Levadna, O.A. Gamova

Three-component systems CaO–CoO–MoO3, CoO–Al2O3–MoO3 and CaO–Al2O3–MoO3 are characterized in this work. The results of the research of the subsolidus structure of the systems under study are given. Diagrams of the systems in the field of the subsolidus are presented. The calculations of the changes of Gibbs free energy are performed at different temperatures for the model reactions. The thermodynamic and geometric topological calculations based on the developed thermodynamic database allow establishing the direction of solid-phase reactions in the three-component systems CaO–CoO–MoO3, CoO–Al2O3–MoO3 and CaO–Al2O3–MoO3 with the participation of steadily existing compounds; as a result, all conodes in these systems have been determined. The main geometric topological calculations of elementary triangles and phases of systems are performed. Geometric topological system performance is important for the prediction of the accuracy of a dosage of components and the duration of their mixing before synthesis to obtain materials with the specified phase composition. The data on subsolidus structure of the considered three-component systems are essential for further forecasting phase structure of the aluminate cements fabricated with the use of the waste of cobalt catalysts that additionally contain molybdenum oxide.

5-13

Authors: R.D. Apostolova, A.S. Baskevich

Potassium vanadate was synthesized by chemical and electrochemical deposition from a solution of potassium metavanadate to use in cathodes of lithium batteries. After annealing (350C), the deposits contained KV6O15 vanadate mixed with hydrated vanadium oxides. The prepared materials were tested in the electrodes with an electrically conducting additive. The reversible capacity of the synthesized material obtained by chemical deposition in an electrode (11.068.00.25 mm) in the electrolyte containing 1 mol L–1 LiClO4, propylene carbonate and dimethoxyethane was 140–150 mA h g–1 in the voltage range of 3.8–2.4 V. The capacity of the samples with a mass of 30–40 mg cm–2 obtained by deposition on the anode, reached 237 mA h g–1 with respect to the active component in 8–10 cycles. The observed discharge rate (0.1 mA cm–2) of potassium vanadate with particle sizes exceeding the submicron level and with a mass of 30–40 mg cm–2 was comparable to that of a nanometer K2V8O21 vanadate with a mass of 1 mg cm–2 (50 mA g–1). The ability of the synthesized vanadates to genarate more than 200 mA h g–1 in the voltage range of 3.8–2.4 V can provide a higher energy than that of nanomaterials-analogues in the range of 3.8– (1.0–1.5) V.

22-26

Authors: S.A. Varenichenko, O.K. Farat, A.V. Mazepa, V.I. Markov

New Schiff bases were synthesized by the reaction of tetracyclic formyl derivatives of xanthenes with aromatic amines in the presence of a vapor of acetic acid drops. The structures of these compounds were investigated by FTIR, NMR spectroscopies and mass-spectrometric technique. Formyl xanthenes showed absorption and emission in the range of 424–435 nm and 524–559 nm, respectively, in solvents with different polarities. Initial formyl xanthenes were characterized by a sufficiently high Stokes shift of 100–130 nm and a moderate fluorescence quantum yield. The prepared Schiff bases exhibit no fluorescence, with the exception of two products with antranilic acid. These compounds show weakly structured absorption spectra with maxima at 527 nm and 532 nm. Luminescence maxima were found in the range of 582 and 598 nm; as a result, the prepared compounds are characterized by low fluorescence quantum yields in the range of 0.01–0.02 in acetonitrile solution and the Stokes shift of 55 nm and 65 nm.

34-41

Authors: M.M. Zhyhailo, O.I. Demchyna, I.Yu. Yevchuk, B.I. Rachiy, V.V. Kochubey

The synthesis of a series of hybrid polymer-inorganic membranes based on acrylic monomers (acrylic acid, acrylonitrile and 3-sulfopropylacrylate potassium salt) and sol-gel system 3-methacryloxypropyltrimethoxysilane–ethanol–water with various ratios organic/inorganic is reported in this paper. The synthetic procedure includes UV-initiated polymerization of monomers in the presence of photoinitiator and cross-linker and sol-gel process in situ. A high content of gel fraction (>95%) indicates the successful synthesis and formation of cross-linked polymer-inorganic structures insoluble in organic solvents and water. Investigations performed by means of impedance spectroscopy showed high proton conductivity of membranes (10–4–10–2 S cm–1) and its dependence on temperature and material composition. The prepared membranes have relatively good chemical stability in the time interval of testing and high ion-exchange capacity (1.12–1.68 meq g–1). Thermogravimetric study showed the influence of the content of inorganic component on the increase of thermal stability of the membranes. Consequently, taking into account the complex of the characteristics, the synthesized organic-inorganic materials is a potential candidate for DMFC application.

48-53

Authors: Y.I. Koltsova, S.V. Nikitin

The paper is focused on increasing the crystallization degree of porous glass-crystalline materials to improve their mechanical properties. The search for a favorable heat treatment method is one of the ways to achieve this. This study reveals the influence of the temperature-time mode on the samples properties in the course of the roasting process; the procedure includes endurance at the temperature of 600C during cooling. It is determined that the application of the specified roasting mode has a number of advantages in comparison with slow cooling of the samples together with a furnace. The proposed method of roast provides a decrease in the content of a crystalline component and ensures a significant decrease in the coefficient of constructive quality of the studied materials (on average 16.3%). The influence of micro-wollastonite additives in the amount of 1.5–7.5 mass fractions (beyond 100%) on the properties of experimental porous glass-ceramic materials is also investigated. The additive increases the crystallization degree and allows achieving the formation of wollastonite crystals. It is established that the use of the additive under consideration increases the mechanical characteristics of the samples (for instance, coefficient of constructive quality increases from 15.17 to 16.33) due to crystallization of wollastonite in the interporous partitions; this provides a reinforcing effect with respect to the whole material.

58-64

Authors: H. Lavrenyuk, B. Mykhalichko

This paper reports the results of determination of tensile strength, surface hardness, water resistance and chemical resistance of polymer materials based on the self-extinguishing epoxy-amine composites modified with copper(II) carbonate. This allowed forming the basics of a new type of polymer materials with enhanced physicochemical and mechanical properties. The results of the experiments showed that the use of CuCO3, which is considered as a flame-retardant agent of epoxy-amine composites, not only suppresses the spread of the flame, thereby effectively reducing the fire hazard but also improves the performance characteristics of the produced polymer coatings. Due to its exceptional complexing ability, copper(II) carbonate is readily incorporated into the structure of an epoxy polymer, which ensures that the composite materials retain their performance characteristics at an appropriate level. The addition of CuCO3 to epoxy-amine composites in the amount of 20–40 mass parts per 100 mass parts of binder increases the tensile strength and the surface hardness by 67.8–87.2% and 19.7–21.5%, respectively, in comparison with the original composition. It was also found that epoxy-amine composites with CuCO3 additives are characterized by increased water resistance and resistance to aggressive environments.

71-76

Authors: A.M. Makeiev, T.Ie. Keda, L.M. Potiha, O.A. Zaporozhets

New derivatives of [1,2,4]triazoloazines substituted in the amine-rearrangement are synthesized using a novel approach that is based on the cyclization of methyl (E)-4-hydroxy-4H-1,2,4-triazole-4-amine salts with bromo-2-butenoate and methyl 2-(bromomethyl)benzoate. The influence of the solvation shell of dimethyl sulfoxide, acetonitrile, ethanol and their mixture with water on the spectral characteristics of the new compounds in solutions was investigated. The molecules are sensitive to changing the solvate shell in solutions; they are characterized by a positive solvatochromic effect when solvent polarity is increased. Their solutions in dimethyl sulfoxide show intense blue fluorescence (em=460–468 nm), which decays with time. It was shown that water quenches the fluorescence of 1-amino[1,2,4]triazolo[1,5-b]isoquinoline-1-ol-10-olate in organic solvents. The intensity of fluorescence of 1-amino-10-hydroxy-1H,5H,10H-[1,2,4]triazolo[1,5-b]isoquinoline-4-one increases with an increase in the water concentration in dimethyl sulfoxide in the range of 0.05 to 0,5% (v/v). This means that this molecule can serve as a highly sensitive probe for the determination of water level in dimethyl sulfoxide.

84-92

Authors: A.V. Mishchenko, E.V. Mishchenko, E.A. Venger, D.S. Kachuk, T.A. Popovych

The paper reports the results of the study on the hydrolytic stability of films obtained from aqueous dispersions of polyurethane ionomers of sulfonate and carboxylate types, in particular the effect of the process duration of films in aqueous solutions of soda and surface-active substances on the bursting tension during stretching was investigated. This indicator is important when using dispersions as binders in pigment compositions for the printing of textile materials, because the indicators of the stability of colorings to wet treatments, in particular to washing, depend on the properties of dispersions. It was found that the investigated polyurethane ionomers do not provide the stability indicators, which would be expected from a polyurethane nature of the binder. An assumption was made that this results from an insufficient stability of some polyurethanes to hydrolysis. For increasing the polymer stability to hydrolysis and the stability of colorings to wet treatments, we tested the possibility of increasing the density of a three-dimensional structure of polyurethane. To this end, pre-condensates of thermosetting resins, which are widely used in finishing works, were used. An increase in the stability of both films of polyurethane ionomers and the coloring formed was stated when using the binders of the specified type in the presence of pre-condensates of thermosetting resins. The mechanism of the action of the pre-condensates of thermosetting resins was determined in the formation of polyurethane films. It was established that a high efficiency of additives of pre-condensates of thermosetting resins towards the polyurethane binder is ensured by the resin formation and the formation of a composite-type film with increased strength characteristics on the surface of a fabric. The formation of a polymer system of the specified type provides high coloring stability and improves performance characteristics of a textile material.

104-111

Authors: O.V. Perlova, E.I. Tekmenzi, N.А. Perlova, A.P. Polikarpov

Some characteristics of sorption recovery and concentration of uranyl ions from model nitrate solutions by fibrous ion exchangers FIBAN C-1 (a cation exchanger) and FIBAN AC-22V (an amino-carboxyl polyampholyte) under dynamic conditions were established. It was shown that effective recovery and concentration of uranium(VI) is combined with a high rate of uranium sorption. Quantitative characteristics of uranium sorption under dynamic conditions (dynamic exchange capacity, total dynamic exchange capacity, uranium content in the phase of the sorbent and sorption rate) were calculated. It was established that the fibrous cation exchanger FIBAN C-1 manifested better uranium(VI) sorption properties from model nitrate solutions (maximum sorption is equal to 0.23–0.34 mmolg–1) and concentration of these solutions (100–115 times) than polyampholyte FIBAN AC-22V (maximum sorption is equal to 0.011–0.014 mmolg–1, concentration is only 2.5 times). It was shown that a 10-fold increase in the rate of solutions transmission through FIBAN fibrous ion exchangers (from 2.5 to 25 cm3min–1) resulted in an insignificant degradation (~1.2–1.5 times) of the characteristics of sorption process. It was experimentally found that the initial form of the fibrous ion exchangers can be fully restored by passing of 10 and 16 column volumes of a 0.5 M HNO3 solution through the ion exchangers FIBAN C-1 and FIBAN AC-22V (in uranyl form), respectively.

118-125

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

The viscoelastic properties of epoxy resin-based composites ED-20 in a mixture with aliphatic epoxy resin DEG-1 have been determined as functions of the applied industrial polyamine hardener and additional heat treatment (at the temperatures of 60–140С). The differences in the thermomechanical and physical-mechanical properties, and wear resistance of the composites have been stated resulted from the change in the ratio of the energies of elastic and viscous deformation. The ratio of the energies of elastic and viscous deformation of composites in a dynamic loading mode is influenced by the formed spatial cross-linked structure of the epoxy matrix. The effects of the temperature of additional heat treatment on the change in thermomechanical properties and the nature of the destruction of epoxy composites have been shown. It has been proposed to apply a combined heat treatment conditions (80+100C). To achieve optimum viscoelastic properties after hardening at 20C, it is expedient to heat-treat the obtained epoxy composites in a vitreous state at temperatures close to vitrification temperature and use a Polyamine B hardener.

135-142

Authors: L.O. Snizhko, N.L. Gurevina, O.O. Kalinichenko, V.O. Holovenko, K.V. Roienko

Plasma electrolytic oxidation of lightweight metals performed in water-based solutions is usually accompanied by both the release of a large volume of gases (mainly H2 and O2) and heat emission. Today, the existing electrochemical concepts that tend to explain the oxidation mechanisms involved in the metal conversion under the plasma electrolytic oxidation discharge regime do not provide a clear explanation about these phenomena. In this paper, the critical role of the exothermic thermochemical reactions that occur in micro-discharges between the metal particles emitted from the substrate by discharges and the surrounding water vapour (2Al+6H2O=2Al(OH)3+3H2+Q) is considered. This reaction is thermodynamically favourable over a wide temperature range from room temperature to temperatures far in excess of the melting point of aluminium (660C). This means that the main product of the reaction between dispersed aluminium and water is aluminium hydroxide Al(OH)3. At the same time, conditions realised in spark discharges allowed forming also Al2O3, because it is the most stable product at high temperatures. Comparison between the calculated amount of aluminium oxide, performed using the characteristics of individual discharges, and experimental results taken from the literature revealed that the thermochemical reactions is mainly responsible for both the large amount of gas release and heat emission during the plasma electrolytic oxidation of aluminium.

153-159

Authors: A.B. Tarnavskyi, U.V. Khromyak, R.B. Veselivskyy

The data of temperature-modulated differential scanning calorimetry, thermomechanical and microscopic analyses allowed establishing the effects of poly-N-vinylpyrrolidone (PVP) on the suprаmоleculаr structure in the mixtures of PА-6–PVP and PА-66/6–PVP, crystallite sizes, degree of material crystallinity and temperature of physical transitions. The thermodynamic compatibility between the components of polyamide–PVP mixtures in the viscous-fluid state is determined. The compatibility between PА-6 and PVP is manifested as one endo-peak observed in the curves of differential scanning calorimetry. The endо-effect is somewhat blurred for the case of PА-66/6. This is explained by the presence of links with various structures in PА-66/6. An increase in PVP content in the mixtures also leads to the growth of the maximal temperatures of peaks in the processes of melting and crystallization and the expansion of their temperature and time ranges. Thermomechanical study showed that the melting temperature increases with an increase in the content of PVP in the case of PА-6–PVP mixtures, whereas it decreases in the case of PА-66/6–PVP mixtures. A decrease of deformation in the area of highly elastic state is observed. Microscopic study of the structure of the materials based on modified polyamides revealed the growth of the size of suprаmоleculаr formations and significant changes in the interphase layers. However, the size of crystal formations in the mixtures of PА-66/6–PVP is slightly smaller than in PА-6.

5-11

Authors: V.N. Anisimov, V.V. Anisimov

We showed the inability to evaluate the properties and the processing conditions of polyurethanes based of their hardness, although such evaluation is usually used in their marking, this approach does not take into account the peculiarities of molecular structure and the nature of the initial components. A scientifically substantiated approach to the creation of materials based on block-polyurethanes (BPU) of different morphology was developed. The effect of rigid phase content was studied. The characteristic points of the rigid blocks content, Рс1 and Рс2, which correspond to the conditions of geometric phase transitions, were determined and the conditions of the formation of geometric phase morphology with optimal parameters (Рс1РсРс2) were found. Thus, there is a noticeable inflection in all of these graphic dependences for the BPU based on oligo(tetramethylene ether) glycol at points with Pc1=30% and Pc2=50% (conditional strength at tension, elasticity modulus, relative elongation at rupture, hardness, softening temperature, and degree of crystallinity). The technological parameters of BPU molding under pressure with optimal phase morphology, including rapid prototyping complexes (3D printers), have been established. The recommended parameters allowed productively affecting the process of molding under pressure and preparing qualitative products from the developed composites with a specified complex of properties (gaskets, friction supports, elastic elements of gearing devices, extruded strands, circular rings, plates, tubes, etc.). In addition, due to recycling, we managed to substantially reduce ecological risk and increase the commercial attractiveness.

19-27

Authors: T.M. Boichuk, S.M. Orlyk

Among the problems of reducing the overall level of environmental pollution, the problem of reducing the content of N2O and NO in gas emissions from mobile and stationary sources remains one of the most complex and important. The reduction of N2O by carbon monoxide or hydrocarbons seems to be promising for purification of dilute gas emissions from nitric (I) oxide (<1 vol.% N2O) which are formed in the production of nitric acid and solid fuel combustion processes. The reduction of the inhibitory effect of oxidizing agents (SO2, O2, H2O) is a critical factor in the design of catalysts for DeNOx processes. Monolithic catalysts of a new generation, related to the so-called structured catalysts, are today the most demanded in the processes of ecological catalysis due to the possibility of a more rational use of active components, the increase in productivity and the decrease in the gas-dynamic resistance of a catalytic reactor. We showed that the activity of binary In-, Co-oxide catalysts in the joint reduction of N2O and NO by carbon monoxide depends on the nature of the support (Al2O3, ZrO2), the sequence of the introduction of the active components and the acidic properties of the surface. The deposited In-, Co-oxide catalysts of the zirconium oxide base doped with palladium (0.1%) showed high activity in the joint reduction of N2O and NO by carbon monoxide: 90–99% conversion of N2O, NO and CO was achieved at 450C. The tolerance to the effects of H2O and SO2 was observed. The developed palladium-containing indium-cobalt-oxide structured catalysts (on block carriers of a kaolin-aerosilogel honeycomb structure) are characterized by high activity, moisture and sulfur resistance, low content of platinum metals; they can be used for complex purification of waste gases from nitrogen oxides (N2O, NOx) and CO.

35-40

Authors: O.M. Dykun, A.M. Redko, V.I. Rybachenko, O.I. Dzyuba

Five gossypol Schiff bases were synthesized (with 4-fluoroaniline, 4-methoxyaniline, 3-amino-5-methylisoxazole, 4-aminoantipyrine and aniline) and their structures were established by 1H NMR spectroscopy. The reaction with 2,2'-diphenyl-1-piсrylhydrazyl (DPPH) in the presence of chloride acid was conducted and the correspondent rate constants were determined. The protonation of gossypol Schiff bases in the presence of chloride acid leads to the shift of tautomeric equilibrium from the enamine-enamine form to imine-imine one. Additional O–H groups appear in the structure of the molecule, they are able to react with DPPH). The correlation between the chemical shifts of protons in N–H groups and the rate constants in acid media was shown. Higher values of the chemical shifts of protons in N–H groups of azomethine group indicate a higher reactivity of corresponding Schiff bases. Then the difference in the reactivity of investigated Schiff bases toward DPPH in the presence of chloride acid can be explained by the ability to protonate the nitrogen atom of the azomethine group. The biological activity of a number of gossypol Schiff bases in biotests toward the root system of cucumbers (Cucumis sativus L.) was determined.

46-54

Authors: А.V. Zaichuk, А.А. Amelina

Directed synthesis of blue-green spinel-type ceramic pigments is theoretically justified and experimentally vindicated using the system СoO–MgO–CaO–Al2O3–Cr2O3–TiO2. The slag of aluminothermal production of ferrotitanium with a high content of aluminium (III) oxide (71.5 wt.%) is used as a raw material. It is shown that calcium hexaaluminate is a primary phase of slag which takes part in the formation of magnesium and cobalt aluminate spinels. This allows appreciably reducing the temperature of pigments' firing (to 1150–1200С in the presence of mineralizing additive B2O3). The introduction of chromium (III) oxide into the composition of pigment batches in the amount of 0.1–0.5 mol (9.8–32.1 wt.%) provides blue-green coloring of ceramic pigments (=467–487 nm). The results of physicochemical study shows that the color of the pigments is connected with different ratio between aluminate and chrome spinels in a solid solution (Со, Mg)(Cr, Al)2O4; their crystal size is 4–6 m. The developed spinel pigments exhibit improved chemical stability (water resistance of 99.99%; 1 N HCl acid resistance of 99.97–99.99% and 1 N NaOH alkali resistance of 97.40–99.95%). They can be used to fabricate high-quality glass coatings of a blue-green color range (=472–485 nm).

62-72

Authors: N. Klymentiy, S. Pukas, L. Orovčík, R. Gladyshevskii

The isothermal section of the phase diagram of the ternary system Ti–Cu–Al at the temperature of 800C was investigated using X-ray powder diffraction, microstructural analysis and energy-dispersive X-ray spectroscopy. The homogeneity ranges at 800C of three purely ternary compounds were determined: TiCuxAl3–x, x=0.30(3)–0.60(3) (structure type Cu3Au), TiCu2+xAl1–x, x=0–0.52(2) (structure type MnCu2Al) and TiCuxAl2–x, x=0.54(3)–1.14(3) (structure type MgZn2). The crystal structure of an additional compound near the composition TiAl3 was refined on X-ray powder diffraction data (Ti1.15(2)Cu0.09(1)Al2.76(3), structure type ZrAl3; Pearson symbol tI16, space group I4/mmm, a=3.9159(3), c=16.556(2) Å). This ternary compound, observed at 800C, is probably an extension of the solid solution of the binary high-temperature phase reported as Ti5Al11 with the same structure type. The microhardness of the ternary compounds was measured.

80-88

Authors: Yu.V. Matveichuk

A new film selenate selective electrode was developed. The electrode membrane contains 3,4,5-tris(dodecyloxy)benzyltetroxyethyltrimethylammonium chloride (5 wt.%) as an electroactive component; polyvinylchloride is a polymer matrix (33 wt.%), 1-bromonaphthalene serves as a plasticizer (42 wt.%), p-trifluoroacetylbenzoic acid heptyl ester is a solvating additive (20 wt.%). The electrode shows a wide linear range of 210–6–10–2 mol L–1 Na2SeO4; the slope of the electrode function is 26.00.3 mV decade–1; the lower detection limit is 110–6 mol L–1 Na2SeO4; the working pH range is 2.15–6.3; the potential drift is 0.9 mV h–1; the response time is from 15 to 90 s (depending on the concentration (activity) of SeO42– ions). The electrode shows selectivity towards SeO42– ions in the presence of chloride, bromide, sulfate and other ions; its lifetime is 1 month. The developed electrode was tested in model solutions using both the "introduced–found" method in a variant of the calibration graph and the method of limiting solutions. The electrode was also used to determine selenium in Brazil nuts. The determination of selenate ions by capillary electrophoresis was used as a reference method.

95-100

Authors: Yu. Melnyk, R. Starchevskyi, S. Melnyk

The paper reports the results of the study on the transesterification of sunflower oil triglycerides with 1-butanol in the presence of d-metal oxides. It is shown that the initial rate of the transesterification reaction and the maximum conversion of triglycerides are differently affected by the oxides of different d-metal. A range of the activities of the investigated oxides is identified according to the initial reaction rate and triglyceride conversion attained. The oxides of zinc and nickel (II) are the most active catalysts. The use of ultrasound treatment in the transesterification reaction of triglycerides with 1-butanol in the presence of iron (II) oxide allows increasing their conversion by about 16%. However, even the application of the ultrasound treatment in the presence of the mentioned catalyst ensures a less conversion of triglycerides than that when using the oxides of nickel (II) and zinc. An increase in the molar ratio of triglycerides to 1-butanol up to 1:15 and 1:20 completely reduces the effect obtained by the application of ultrasound in the transesterification process. Thus, it is possible to achieve the triglyceride conversion of above 97% resulted from a 15-fold increase in the molar excess of 1-butanol in the presence of nickel (II) and zinc oxides during 150 min of the reaction. A further increase in the molar ratio of reactants to 1:20 provides an almost complete conversion of triglycerides in the presence of these catalysts, the reaction duration simultaneously decreases to 120 min. There is an extremal dependence of the triglyceride conversion on the catalyst content (FeO) in the reaction mixture. The optimal content of a catalyst in the reaction mixture is 0.25–0.30 wt.%. The obtained results show that some d-metal oxides can be used as highly efficient catalysts of the transesterification reaction.

109-119

Authors: A.I. Nesterenko, N.G. Nesterenko

Quantitative analysis of the energy of the process of hydrodynamic cavitation showed that the collapse of cavitation bubbles is accompanied by the release of energy which is sufficient for the cracking of heavy hydrocarbons. A possibility in principle of intensifying the cracking of petroleum products through the use of hydrodynamic cavitation is shown. A quantitative analysis of the optimal sizes of cavitation bubbles and their volume fraction was carried out. The physicochemical mechanism of the processes occurring in the real experiment on the intensification of cavitation cracking of petroleum products was proposed. The movement of oil in the inlet pipe, in the centrifugal vortex chamber, behind the nozzle of the centrifugal vortex chamber and in the outlet pipe is considered. To describe these processes, the input parameters were taken that can be controlled in a real experiment: the values of excess static pressure at the inlet and outlet of the centrifugal vortex chamber, dimensions and design features of the centrifugal vortex chamber, oil temperature and volume flow rate of a petroleum product. Mathematical simulation of these processes showed that an attached cavity is formed behind the vortex chamber. A complete quantitative description of the attached cavity geometry, axial, peripheral velocity, and static pressure of the oil product flow was obtained. It is shown that the attached cavity plays a dominant role in the process of intensification of cavitation cracking of petroleum products.

127-138

Authors: Z.H. Pikh, R.V. Nebesnyi, A.Z. Pich, V.V. Ivasiv, T.V. Kharandiuk

We studied the mechanism of aldehydes oxidation by the system selenium-containing catalyst–hydrogen peroxide. On the basis of literature data analysis, our experimental results and developed kinetic model of the reaction, we stated that the oxidation of unsaturated aldehydes by Se-containing compounds and hydrogen peroxide occurs through the formation of intermediate active compound of peroxide nature, selenium peracid. Study of the kinetics of reaction with Se-containing catalysts in different oxidation state (0, +4, and +6) showed that the highest reaction rate was observed when selenium oxidation level was +4. It was also found that the nature of solvent significantly affects the reaction rate and solvents can be ranged by their positive effect as follows: formic acid>tertiary alcohols>acetic acid>dioxane>acetone. It was shown that the oxidation reaction in acetic acid occurs even without catalyst but proceeds in several directions that causes low selectivity towards the target products. As a result of kinetic study, we determined that the concentration of hydrogen peroxide had no effect on the reaction rate; however, an increase in water concentration in the reaction mixture (which is introduced into the reaction mixture together with hydrogen peroxide solution) decreases the reaction rate. On the basis of the results of kinetic simulation, we showed that the oxidation of unsaturated and saturated aldehydes occurs through two following ways: it chiefly proceeds through the step of non-catalytic interaction of aldehyde with hydrogen peroxide in the case of saturated aldehydes, whereas this route occurs only to a small extent in the case of unsaturated aldehydes.

150-156

Authors: I.V. Semeniuk, V.V. Kocubei, O.Ya. Karpenko, H.H. Midyana, O.V. Karpenko, V.V. Serheyev

Thermal, titrimetric analysis and UV/Vis spectroscopy were used to study the structural features of molecules of humic acids prepared from different raw materials, such as biohumus, peat, brown coal, and chernozem. Humic acids were extracted from these material by aqueous solutions of potassium hydroxide at the temperature of 50C and precipitated with by a solution of hydrochloric acid at pH<2. The precipitate of humic acids were separated by centrifugation, washed on the filter with distilled water; the purified precipitate was further dried at the temperature of 60–70C. The thermal analysis of the samples of humic acid was performed in air in the temperature range of 20–1000С. On the basis of the thermolysis results, the content of carboxyl and hydroxyl groups in molecules of humic acids was determined and the ratio of aliphatic structures to cyclic ones in humic acids under consideration was calculated. The absorbance was determined by means of UV/Vis-spectroscopy. Its values were used to calculate the ratio of the amount of carbon in aromatic fragments to that in side radicals. The obtained data indicate a high proportion of aliphatic fragments in the structure of humic acids which confirms the data gained by thermal analysis. The total acidity of humic acids was determined by means of the barite method, it conforms with the values obtained by the thermal analysis of the samples under investigation.

163-171

Authors: О.К. Trunova, O.S. Berezhnytska, Ya.V. Fedorov, N.V. Rusakova, S.S. Smola

New monometallic, mixed ligand and polymeric complexes of Sm(III) with unsaturated -diketones (2-methyl-5-phenyl-1-pentene-3,5-dione and 2,6 dimethyl-1-heptene-3,5-dione) and phenatrolin have been synthesized and investigated in solutions and solid state in the present work. The structure and spectral-luminescent characteristics of the synthesized complexes have been determined. It was shown that -diketonate ligands in the complexes were coordinated to the lanthanide ion bidentate cyclically and the coordination environment of the cation remained unchanged during polymerization; however, there was an increase in the symmetry of the polyhedron. It was established that metal complexes and polymers exhibited effective 4f-luminescence in the visible region of the spectrum. The luminescence intensity was higher for mixed-alloy complexes and the luminescent characteristics of the Sm(dmhpd)3 complexes were lower than those for Sm(mphpd)3; but the similar energy differences between the triplet levels of the ligands and the resonance level of lanthanide caused the same intramolecular energy transfer from the -diketonate fragment to the samarium ion. The comparison of spectrophotometric and luminescence characteristics of metal complexes and polymers on their basis was carried out and it was determined that the main parameters of 4f-luminescence (integral intensity and quantum yield) in metal-polymers were considerably increased in comparison with monomeric analogues.

6-16

Authors: A.R. Gaidai, P.V. Vakuliuk, I.M. Furtat, T.V. Murlanova, N.I. Kunytsya, V.A. Tertykh, R.B. Kozakevych, A.H. Grebeniuk, A.A. Golub

This work deals with the preparation of nanocomposites based on pyrogenic silicon matrix modified with ornidazole. The physical, chemical and functional properties of the synthesized nanocomposites were characterized. 13С and 1Н nuclear magnetic resonance and UV spectroscopies were used to study the composition of the prepared nanocomposites (i.e. ornidasils). The presence of ornidazole on the silica surface was proved using elemental analysis, liquid chromatography and high resolution mass spectrometry. Sorption kinetics of active substance and sorption capabilities of ornidasils towards pathogens and proteins was investigated. The PM3 method of quantum chemistry showed that the formation of adsorption complexes on the highly dispersed silica surface occurs due to the hydrogen bonds between the surface groups of silanol and the nitro groups of ornidazole; the water excess will gradually wash away the molecules of ornidazole adsorbed on the surface of silica. The release of ornidazole in the model solution was about 77% of the active compound after 20 min of desorption and further concentration of ornidazole in the solution was maintained at a stable level due to the gradual release of the drug which was experimentally confirmed. The expansion of antimicrobial effect of ornidazole in the nanocomposites for the gram-positive and gram-negative test cultures was established as compared with the initial active compound.

22-29

Authors: M. Litynska, N. Tolstopalova, I. Astrelin, N. Petrus

High arsenic content is typical of natural waters of many countries, including Ukraine. Concentration of arsenic in drinking water, which is higher than 10 g/L, causes a lot of undesirable consequences (hyperkeratosis, cancer, different diseases). It is necessary to develop new methods of arsenic removal and improve the existing ones. Iron-containing adsorbents are ones of the most usable for water treatment in case of pollution by arsenic. Both natural water and wastewaters have complicated mineral composition. That is why the study of influence of other ions is a topical issue. The paper reports the influence of anions (chlorides, sulfates and hydrocarbonates), cations (sodium and calcium) and pH on the arsenate adsorption on the synthesized goethite, hematite and ferrihydrite. The influence of chlorides is ambiguous and an increase of arsenate adsorption efficiency occurs in case of iron (III) oxide and hydroxide. Sulfates and hydrocarbonates significantly impede removal of arsenate for all investigated iron-containing sorbents. The effect of chlorides and sulfates does not practically change in the pH range of model water of 6 to 8, while the presence of hydrocarbonates dramatically deteriorates the process with increasing pH. One can conclude from these data that high concentrations of sulfates and hydrocarbonates are undesirable in waters which are purified from arsenic compounds by iron-containing adsorbents.

35-45

Authors: N.V. Nikolenko, Yu.V. Kalashnikov, A.O. Kostyniuk, A.Yu. Poloz, E.V. Aksenenko

The adsorption of a number of organic acids and bases from aqueous and methanol solutions was studied under static conditions at room temperature. It was shown that the organic compounds are adsorbed on Fe(III) and Mo(VI) oxides and Fe(III) molybdate due to the formation of the surface hydrogen bonds. The possibility of the adsorption by means of a donor-acceptor interaction of the organic compounds with the surface cations Fe3+ was not detected. It was shown that the adsorption energies of organic bases are linearly correlated with the effective charge of nitrogen atoms and their adsorbability changes in the following range: Fe2O3>MoO3>Fe2(MoO4)3. An explanation of these correlations was proposed based on the concept of the domination of electrostatic interactions. Heterogeneous-catalytic oxidation of methanol and formaldehyde was proposed to consider assuming two forms of adsorption of their molecules: via binding of oxygen atoms with Lewis acid sites, or via the interaction of carbon and hydrogen atoms of the C–H bonds with Lewis basic centers of a catalyst. It was concluded that the selectivity of the iron molybdate catalyst in the partial oxidation of methanol can be caused by low adsorbability of intermediate products of the methanol oxidation reaction on the catalyst surface.

53-58

Authors: Y.A. Titov, N.M. Belyavina, M.S. Slobodyanik, V.V. Chumak, O.I. Nakonechna

By using X-ray powder diffraction method, it was determined that scandium atoms in SrNdScO4 slab perovskite-like structure are substituted according to SrNdSc1–хInxO4 type if 0x0.85. A further increase in a degree of substitution of scandium atoms for indium ones in the single-slab SrNdSc1–хInxO4 scandatoindates (x>0.85) results in destruction of a slab structure and formation of a second phase with CaFe2O4 structure type, which quantitative content increases up to ca. 100% at х=1. Orthorhombic crystal structure (Pbca space group) of SrNdSc1–хInxO4 phases with a substitution degree of scandium atoms equal to 0.25, 0.5 and 0.7 was determined by the Rietveld procedure. The base of SrNdSc1–хInxO4 slab peroskite-like structure consists of two-dimensional perovskite-like blocks of one slab of distorted InO6 octahedra joined by vertices. There are no direct (Sc,In)–O–(Sc,In) bonds between the octahedra of adjacent blocks. There is a layer of (Sr,Nd)O9 polyhedra between adjacent blocks, while the –O2–(Sr,Nd)–O2 interblock bonds provide a junction of the perovskite-like blocks. Comparison of structure features of SrNdScO4 scandate and SrNdSc1-xInxO4 phases showed that the isovalent substitution of the scandium atoms for bigger indium atoms in the single-slab SrNdSc1–xInxO4 structure leads to a consistent increase in the deformation degree of (Sr,Nd)О9 interblock polyhedra, the average (Sc, In)– O distance in (Sc,In)O6 octahedra and their inclination to each other, as well as to a significant increase in the length of the (Sr,Nd)–O2 interlock bond (from 0.226(1) nm at x=0 to 0.238(1) nm at x=0.3–0.7). An increase in the distance between the perovskite-like blocks weakens their bonding strength, while an increase in the deformation degree of (Sr,Nd)O9 interblock polyhedra and the inclination of (Sc,In)O6 adjacent octahedra increases the structure tension. The total effect of these factors leads to the destabilization and destruction of the slab perovskite-like structure and causes both the limited range of SrNdSc1–xInxO4 solid solutions with a slab perovskite-like structure (0x0.85) and makes impossible the formation and existence of SrNdInO4 indate with this structure type.

67-73

Authors: А.I. Yanchak, Yu.I. Slyvka, V.V. Kinzhybalo, T.J. Bednarchuk, M.G. Mys'kiv

By means of alternating current electrochemical synthesis with wire copper electrodes in methanolic solutions of corresponding ligands and copper(II) halide salts, two novel copper(I) -complexes [Cu2(dau)Cl1.58Br0.42] (I) and [Cu2(dapa)Cl1.74Br0.26] (II) (where dau and dapa are 1,3-diallylurea and 1,3-diallylparabanate, respectively) were prepared in well-shaped crystalline form and studied with X-ray diffraction method. Compound I crystallizes in orthorhombic crystal system, space group P212121: a=8.047(3) Å, b=8.154(3) Å, c=16.533(5) Å, V=1085.8(76) Å3, Z=4. Compound II crystalizes in monoclinic crystal system, space group I2/a: a=6.420(3) Å, b=8.088(3) Å, c=49.020(9) Å, =90.92(3), V=2545.03(16) Å3, Z=8. Both structures contain two crystallographically independent copper(I) ions with one half in trigonal planar coordination environment and the other half in trigonal pyramidal one. Both compounds are built of parallel copper halide polymeric chains of one type in I and two types in II, cross-linked by organic ligand molecules to produce 3D-polymer bulk in I and 2D-layered structure in II. In compound I, 1,3-diallylurea is both - and -bonded to copper(I) halide chains (by means of two allylic C=C bonds and carbonyl O atom), whereas 1,3-diallylparabanate is a solely -donor ligand in compound II. The structure of II is noteworthy due to the combination of two different chain types that have been previously observed only separately in copper(I) halide coordination compounds.

83-97

Authors: A.V. Slyuzar, Z.O. Znak, Ya.A. Kalymon, R.L. Bukliv

The main methods of purification and processing of hydrogen sulfide-containing gases are reviewed. The methods are classified as non-conversion and conversion ones, according to the nature of physical-chemical and chemical transformations of hydrogen sulfide in these processes. The adsorption, absorption, chemisorption and membrane processes are non-conversion methods. The catalytic solid- and liquid-phase, biological, plasma- and electrochemical processes are conversion methods. Their main advantages and disadvantages of these methods are discussed. The processes that are widely used in industry, especially those used in Ukrainian industry, are described in detail. It is noted that the use of known and traditional methods, which are widely-distributed in industry to purify high debit gases, is economically ineffective for the purification of hydrogen sulfide-containing gases from low debit sources. It is shown that the lack of appropriate gas purification technologies causes the pollution of the environment by harmful gas emissions, the inefficient use of these gases and the necessity of using additional stages of neutralization of generated wastes. A conclusion is drawn about the necessity of wider implementation of the newest methods that would minimize pollution of the environment by sulfur-containing compounds and make these processes cheaper as result of full utilization of hydrogen sulfide and the production of valuable marketable products, hydrogen and fine-dispersed or polymeric sulfur.

109-115

Authors: M.F. Buller, V.A. Robotko

The paper reports the long-term influence (more than 3 years) of water in a liquid and vaporous state on the main properties of double-base propellants. It was established that either a quick increase or a loss of weight due to the moisture migration occurs originally during the experiment (up to 200 days), depending on the relative humidity of an ambient air and the initial content of moisture in a propellant. Subsequently (more than 200 days), a continuous weight loss of the samples was observed that is explained by the removal of volatile components (i.e. liquid plasticizers) from a propellant. Using the obtained experimental data, the diffusion coefficients of moisture and propellant volatile components were calculated. Diffusion coefficients of volatile components do not depend on the humidity of an ambient air. The effects of atmospheric moisture during the experiment on the combustion heat and density of double-base propellants were analyzed. The process of migration of double-base propellant components into a surrounding aqueous medium was investigated in the course of a long-term exposure (more than 2 years). On the basis of the performed study, diffusion coefficients of nitroglycerine, dinitrotoluene and centralite-ІІ into water were calculated. Migration of double-base propellant components into water occurs from a thin external layer of the propellant element and is determined by the low solubility of the components of double-base propellants.

123-131

Authors: A. Kityk, V. Protsenko, V. Pavlik, M. Boča

High-temperature corrosion of stainless steels AISI 316 and AISI 304 in a molten "solar salt" used as a heat transfer fluid in concentrating solar power (60 wt.% NaNO3 and 40 wt.% KNO3) was investigated at the temperature of 550C. It was shown that the corrosion rate is influenced by the composition of stainless steel and the presence of impurities NaCl in the solar salt. With an increase in the content of sodium chloride impurity in the solar salt, the corrosion rate of both stainless steels increases. The corrosion resistance to the destruction of stainless steels AISI 316 and AISI 304 is provided by the formation of (Cr,Fe)2O3 oxide film on the surface of the samples. Thus AISI 304 stainless steel with chromium content of ca. 20% shows higher corrosion resistance in the solar salt than AISI 316 stainless steel with lower chromium content (ca. 18%). It is known that AISI 304 stainless steel additionally contains molybdenum and a higher content of nickel. The presence of these transition metals in the composition of stainless steel also affects the formation of a protective oxide film that prevents further corrosion damage of steel samples.

139-144

Authors: L.Ya. Parashchuk, V.V. Kochubey, L.I. Odosiy, S.V. Korolko

The effect of the cement type, from which engineering protective constructions are produced, on the value of the linear absorption coefficient of radiation flow has been investigated. The chemical and mineralogical composition of cement for the protective concrete was selected so that hydrated new-formations with the highest possible content of chemically bound water can be formed when hardened. The differential thermal analysis was conducted using a derivatograph Q-1500 D of Paulic-Paulic-Erdey system. Based on the obtained data, the quantitative composition of hydration products of cements under study was determined. A change in radiation intensity (in becquerel) was experimentally measured after passing through the concrete samples based on the Portland cement PC II/A-S 400 and the expansive Portland limestone cement PLC-5. Using the law of the weakening of a narrow monoenergetic beam of -quanta after passing through a substance, a linear absorption coefficient was calculated for the concrete samples of different composition. By means of special mechanical and physicochemical methods, the relationships between the processes of structure formation and the protective characteristics of the samples have been established. It was shown that hydrated compounds formed in the course of hydration of a cement constituent allow increasing the linear absorption coefficient together with raising the level of protection.

151-157

Authors: O.V. Savvova, A.F. Lyahovskiy, N.K. Blinova, G.K. Voronov, S.A. Ryabinina, V.L. Topchyi

The paper reports promising directions of development of glass-ceramic materials using in the military sector of industry for the production of protective armor plates which are exploited under the conditions of high-speed mechanical stressing and action of electromagnetic waves. The main types and areas of application of protective glass-ceramic materials with high radio-transparency and armor protection capacity are analyzed. The purpose of this work was to develop the components of impact-resistant glass-ceramic materials and obtain competitive radio-transparent light armor structures. The compositions of glass-ceramic materials based on lithium disilicate, -spodumene or mullite (80 vol.%) were chosen, these materials being prepared under the conditions of low temperature thermal treatment and characterized by high mechanical properties. The influence of chemical composition, structure of glass-ceramic materials and current frequency on the change of their electrical properties has been established. The developed glass-ceramic materials show improved mechanical properties and radio-transparency in a wide range of frequencies which allows using them as protective structures for radio equipment.

166-175

Authors: О.S. Khomenko, N.M. Sribniak, S.O. Hretsai, I.F. Teliushchenko, V.D. Ivchenko, V.V. Dushyn

The work was aimed at improving the production technology of porous ceramic blocks and improving their operational properties. It was established that the introduction of a complex of burning additives, which contains the wastes of pulp and paper industry, ash from thermal power-station and sawdust, into the composition of ceramic mass allows intensifying the processes of drying of semi-finished products and firing of finished products. The specified additives burn out at different temperatures during burning process and emit heat, which promotes reducing fuel consumption and allows saving energy. When the additives burn out, a porous structure of products is formed which leads to the improvement of their thermal insulation capacity. It is important that the selected complex of additives ensures an increase in the mechanical strength of the products by almost 4–4.5 times as compared with the products of the base composition. The rational amounts of additive components (relative to 100 wt.% ceramic mass) are as follows (wt.%): 10 sawdust, 5 wastes of pulp and paper industry, and 8 ash. The main properties of porous blocks are as follows: the density of 814 kg m–3, the water absorption of 13.7%, the mechanical compressive strength of to 9.2 MPa, and the thermal conductivity of 0.29 W (m C)–1.

181-185

Authors: M.D. Koshel'

This communication is devoted to the memory of outstanding Ukrainian electrochemist Professor O.S. Ksenzhek. The communication describes the main stages of the life and research activities of Prof. O.S. Ksenzhek.

5-11

Authors: K.I. Kuznetsova, V.B. Vostres, R.I. Fleychuk, O.I. Hevus

A series of novel surfactants on the basis of pentaerythritol derivatives and 3,3-disubstituted oxetanes basis was synthesized. Among other substances, a nonionic peroxy surfactant containing a polyethylene glycol fragment was prepared by the interaction of bromo dihydroperoxide (a pentaerythritol derivative) with polyethylene glycol methyl ether. The consequent transformations of 2,2-di[(tert-butylperoxy)methyl]propan-1,3-diol, through the stages of the formation of dimaleate with the participation of two hydroxyl groups, the formation of acyl dichloride and a further reaction with polyethylene glycol, yields a goal peroxy surface-active monomer belonging to asymmetric esters of maleic acid. A nonionic surfactant containing a residual of higher fatty acid and a polyethylene glycol fragment was prepared by the esterification of a dihydroxy substituted oxetane with oleic acid and the subsequent oxetane ring opening of the obtained monoethylated polyethylene glycol diester. The effects of the reaction conditions on the yield and the composition of interaction products were investigated. The dependences of the surface tension of aqueous solutions of the obtained surfactants on their concentrations were established; the values of critical micelle concentrations were determined.

18-24

Authors: R.S. Petryshyn, Z.M. Yaremko, M.M. Soltys

The dependence of the surface potential of a double electric layer on the electrolyte concentration in highly concentrated nano-disperse systems are discussed in this paper. A model of the double electric layer is substantiated which takes into account the changes in the diffusion coefficient and electric mobility of counterions in an electric field due to an increase in the concentration of counterions and surface potential. According to the proposed model, the ratio of the concentration of counterions at the interphase boundary to its concentration in the volume of a disperse system is smaller than the similar ratio calculated via the classical Gouy-Chapman theory. The obtained results are used to estimate the excess of counterions in the double electric layer in comparison with their amount in the volume of the disperse system. The dependences of the surplus of counterions in a double electric layer on the surface charge and geometric characteristics of the disperse system, such as the thickness of the double electric layer and the characteristic parameter of the disperse system (measured as half of the distance between the solid surfaces in highly concentrated disperse systems) are established. An increase in the ratio of the thickness of a double electric layer to the characteristic parameter of the disperse system leads to an increase in the surplus of counterions in a double electric layer.

30-38

Authors: Yu.I. Slyvka, N.T. Pokhodylo, M.G. Mys'kiv

Three new copper(I) ,-complexes with 1-(2-fluorophenyl)-((2-F-Ph)TSA) and 1-(2-ethoxyphenyl)-((2-EtO-Ph)TSA) 5-allylsulfanyl-1H-tetrazoles were synthesized in a single crystal form and structurally characterized by X-ray diffraction method. Crystals of complexes [Cu{(2-F-Ph)TSA}(NH2SO3)] (I), [Cu4{(2-F-Ph)TSA}2Cl4] (II) and [Cu2{(2-EtO-Ph)TSA}2(H2O)2](NO3)2 (III) were obtained under conditions of the alternating-current electrochemical synthesis starting from the alcohol solution of the appropriate organic ligand and copper(II) salt. [Cu{(2-F-Ph)TSA}(NH2SO3)] (I) crystallizes in acentric space group P212121 (a=7.545(3) Å, b=12.890(4) Å, c=14.249(4) Å, V=1385.8(8) Å3, Z=4) and characterizes by a formation of polymeric chains with bridging sulfamate anions. π-Complexes [Cu4{(2-F-Ph)TSA}2Cl4] (II) and [Cu2{(2-EtO-Ph)TSA}2(H2O)2](NO3)2 (III) crystallize in the centrosymmetric space group P-1 (II: a=7.837(3) Å, b=8.695(3) Å, c=11.429(4) Å, =109.61(3), =93.82(3), =105.08(3), V=698.1(5) Å3, Z=1; III: a=8.094(3) Å, b=10.243(4) Å, c=11.221(4) Å, =113.44(3), =97.11(3), =106.79(3), V=786.4(5) Å3, Z=1)), but they show a significant difference in the fragment organization. Compound III is built of centrosymmetric [Cu2{(2-EtO-Ph)TSA}2(H2O)2]2+ dimers in which (2-EtO-Ph)TSA acts as a tridentate chelate-bridging ,-ligand. Molecule (2-F-Ph)TSA in II causes a formation of "stepped cubane" tetramer Cu4Cl4. A brief review of all known Cu(I) -compounds with allyl substituted 1-aryl-1H-tetrazole-5-thiols is given.

47-54

Authors: O.M. Usachev, A.V. Rysich, M.P. Velichko, G.M. Rozantsev, S.V. Radio

The method of pH-potentiometric titration and mathematical simulation using CLINP 2.1 software in the acidity range Z=(HCl)/(Na2WO4)=0.0–2.2 (where (HCl) and (Na2WO4) are the molar quantities of hydrochloric acid and sodium tungstate, respectively) were used to study complex formation in the aqueous-glycerine solution Na2WO4–HCl–NaCl–H2O–C3H5(ОН)3 (С(Na2WO4)=510–3 mol/L, ionic strength I(NaCl)=0.1 mol/L, volume content of glycerine of 10 to 50%). Models of equilibrium processes of the formation of isopoly tungstate anions were developed which adequately describe the experimental dependences pH vs. Z. The Newton (quazi-Newton) method was used to calculate the logarithms of equilibrium concentration constants of the formation of isopoly tungstate anions. Diagrams of isopoly tungstate anions distribution as a function of acidity were plotted for aqueous-glycerine solutions. It was stated that tetratungstate anion ([W4O14(OH)2]6–) is formed in aqueous-glycerine solutions, in contrast to aqueous solutions and H2O–DMF (DMF is N,N-dimethylformamide) and H2O–DMSO (DMSO is dimethyl sulfoxide) systems. Tetratungstate anion initially changes into hexatungstate ([W6O20(OH)2]6–) and then transformed into acid paratungstate B anion (Н[W12O40(OH)2]9–). At the same time, it is worth mentioning that hexatungstate anion fully participates in the consecutive process of tetrahexaparatungstate B anion transformations in solutions containing glycerine, while the concentration of [W6O20(OH)2]6– remains stationary at a fixed acidity in DMF or DMSO containing solutions. Hydrolytic conversion of acid paratungstate B anion into paratungstate ([W12O40(OH)2]10–) and protonated heptatungstate ([HW7O24]5–) anions occurs in the range of existence of paratungstate anions. The content of the protonated heptatungstate anions increases and becomes dominant as glycerine content in the solution grows. The behavior of decatungstate anion and its protonated forms was determined in relation to an increase in glycerine content. It was found that a high content of decatungstate anion and its protonated forms was observed at high Z values (Z>1.60). This makes such solutions promising for the synthesis of salts with Hx[W10O32](4–x)– (x=0–3) anions.

64-70

Authors: R.D. Apostolova

In order to replace Li-ion batteries that do not meet the requirements of consumers for cost energy and safety, an alternative Mg-battery has been previously offered. An approach to the development of Mg-battery was suggested, according to which the required capacity of magnesiation can be achieved through capacitive non-faraday processes and surface reactions involving an electrolyte. This approach was successful in anodes for Mg-battery based on nano-sized meter oxides Mn2O3, Mn3O4 and MnO. In this work, we synthesized and tested Mn2O3 and Mn3O4 oxides with a particle size above the submicron level, which are environmentally less dangerous than nanoscale analogs. The synthesized oxides are used in a composition with a Norit carbon filler in a magnesium perchlorate electrolyte based on dimethylformamid with a magnesium counter-electrode. The starting capacity of (Mn2O3, Mn3O4, Norit) magnesiation reaches 160–200 mA h g-1. The exchange current in the system "composite electrode/electrolyte" is 1.510–5 A cm–2. The resistance to the charge transfer across the electrolyte/Mg-electrode interface associated with surface effects on magnesium reaches 30 k cm2. The potentiality of (Mn2O3, Mn3O4, Norit)-electrode coupled with magnesium in a magnesium-perchlorate electrolyte based on dimethylformamide are limited by inefficient conversion of the Mg-electrode.

79-86

Authors: V.A. Vekshyn, E.R. Grabovetskaya

Kinetics of the selective reduction of nitrogen oxides by using ammonia on a supported cellular platinum catalyst is considered in the article. The calculations allowed determining the kinetic areas of these reactions on the catalysts concerned. The effects of temperature and volumetric flow rate on the efficiency of the purification process were investigated. The values of the rate constants for nitrogen oxides reduction and ammonia oxidation reactions were calculated on the basis of experimental studies with the use of mathematical modeling methods. The influence of monobasic organic acids, acetic and formic acids, on the activity of the catalysts of this type was determined. The samples of catalysts modified with formic acid showed the highest activity. This fact can be explained by a high rate of the main reactions of NOx reduction compared to the rate of ammonia oxidation side reactions. The causes of a decrease in the activity of catalysts with change in temperature were established. The surplus of temperature results in a decrease in the concentration of ammonia below stoichiometry, which leads to the reduction in effectiveness of the process.

93-98

Authors: E.A. Dzura, I.V. Markova

The formation of additional chemical bonds in rubber-fiber composites is considered and compared with rubber modified by m-phenylenebismaleimide containing only dispersed fillers. It is shown that the nature and content of dispersed fillers have a significant impact on the adhesive strength of polycaproamide fibers with rubber containing this modifier. The adhesive strength of rubbers containing m-phenylenebismaleimide with polycaproamide fibers depends not only on their specific surface of the fillers but also on the pH of their aqueous extract. The effectiveness of the fillers increases in the following series: Ultrasil VN-3

106-111

Authors: N.N. Rulyov, V.V. Lukianova, O.V. Kravtchenko

Oil-containing effluents from food processing factories belong to the of industrial discharge wastes which are very difficult to treat because they contain both emulsified oils and solid organic impurities. This paper considers the availability of ultraflocculation and microflotation methods for the phase separation of oily cleaning solutions which are regularly used to clean production equipment at roasted nuts snack factories. Studies on flocculant selection were performed using actual liquid wastes from JSC "Riber and San Rasha Production" factory by means of a device "UltraflockTester" designed and produced by "Turboflotservice" company. The device includes a mini-flocculator and an optoelectronic measuring system used to establish flocculation efficiency by the determination of relative mean size of floccules and water clarification rate. It was demonstrated that sulfate acid (1.9–2.0 L m–3) as well as a neutralizer produced by "ChemiLine" (13–14 L m–3) can be effectively used to reduce suspension pH from 13.6 to 7.5. Experimental findings proved that the best results of phase separation of waste oil-containing detergent solutions were achieved when applying cationic high-molecular flocculant "Praestol-658-BC-S" produced by Ashland Company. The flocculant consumption which ensures a high degree of the aqueous phase clarification is 60–70 mg L–1. It was stated that the best regime of ultraflocculation treatment lasts 5 seconds when the shear rate of medium within the flocculator reaches 2000 s–1.

121-126

Authors: V.G. Sozontov, O.G. Arkhypov, O.V. Suvorin, V.M. Moskalyk, I.L. Kovalenko

The present work considers the main characteristics of phase equilibrium "liquid–vapor" in a multicomponent stratified system "nitrogen oxides–nitric acid–water" at a pressure of 0.1–1.1 MPa. The method is developed which allows calculating the composition of vapor phase and involves the polymerization of nitrogen dioxide and the formation of dinitrogen trioxide. Using the values of partial pressures of NO and NO2, the particular equilibrium constant of the reaction of acid formation is calculated. It is shown that the dependence of the logarithm of particular equilibrium constant on the equilibrium HNO3 concentration is linear at the studied mass ratio N2O4:H2O=1:2…12:1 and the initial concentration of nitric acid of 40.0–68.4 wt.%. This indicates that particular equilibrium constant does not depend on the pressure. It is established that the particular equilibrium constant can be determined taking the overall equilibrium constant calculated via thermodynamic constants and the particular equilibrium constant calculated from the partial pressures of HNO3 and H2O. The composition of the vapor phase is calculated and the experimental data are shown to satisfactorily agree with the data obtained for the thermodynamic functions. A relative error between experimental and calculated data is about 5%.

135-143

Authors: M.O. Chaban, L.M. Rozhdestvenska, Y.S. Dzyazko

This work is dealing with the problem of selective extraction of Li+ ions from combined solutions by electromembrane method. A sorbent based on lithium-substituted double oxide of titanium (IV) and manganese (IV) are used. The effect of the heat treatment of the sorbent on the sorption of Li+ is studied. An increase in the temperature of the preheating from 500 to 600C does not significantly affect the sorption, but the diffusion coefficient of the sorbed ions decreases from 7.310–12 to 5.910–13 m2s–1. At the same time, the selectivity towards Li+ ions increases, and the selectivity towards Na+, K+, Ca2+, and Mg2+ ions decreases. It is noted that such a change in properties occurs due to the formation of Li0.75Mn0.25Ti2O4 at 600C, the presence of this phase in the sorbent being proven. It is established that the function of the sorbent in the membrane system comes to the turbulization of the solution flow. However, under the action of alkalization of the solution near the surface of the sorbent granules, the sorption capacity increases from 0.08 to 0.52 mmolg–1 with increasing the voltage from 3 to 20 V. In this case, the capacities towards Na+ and K+ ions can be reduced by an order and by two orders of magnitude, respectively. After regeneration of the sorbent from the eluate, lithium carbonate is precipitated. This indicates that the compound may be a by-product in the electrolytic desalination of seawater: the granules of double oxide perform in this case a double function of both sorbents and spacers.

150-151

Authors: O.A. Pivovarov, O.V. Chervakov, Yu.M. Kobelchuk

This communication is devoted to the 80th anniversary of the birthday of Professor M.Y. Kuzmenko. He has made a great contribution to the methods of synthesis of new organometallic polymers and polymeric materials on their basis. The communication describes the main stages of the life and research activities of Prof. M.Y. Kuzmenko.