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

9-13

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

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

20-24

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

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

29-34

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

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

40-45

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

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

61-65

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

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

72-77

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

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

9-13

Authors: A.O. Kolbasiuk, A.S. Bushuev, G.A. Galstyan

The kinetics of the catalytic oxidation of ethylbenzene by ozone-air mixture in acetic acid is investigated. It is established that the selectivity of ethylbenzene oxidation by ethyl group increases significantly in the presence of manganese(II) acetate, whereas such an increase is low under the conditions of the catalysis by cobalt(II) acetate, and it almost does not change when using palladium, nickel and chromium acetates. The selectivity of the oxidation with side chain reaches 76% in the presence of manganese(II) acetate at a temperature of 283 K. Acetophenone (66%), 1-phenylethanol acetate (10%), and trace amounts of phenylglyoxylic and benzoic acids are found in reaction products; carbon(IV) oxide is detected in gaseous wastes. The main role of ozone catalysis consists in generating an oxidized form of manganese (i.e. Mn(IV)) which initiates the oxidation of ethylbenzene in side chain. We stated that 3.6 moles of ozone are consumed per 1 mole of ethylbenzene which has reacted; this is much higher than its theoretical needs for the formation of acetophenone and 1-phenylethanol acetate. The initial rate of ethylbenzene oxidation depends on the contents of substrate, catalyst and ozone; this is a first order reaction with respect to each of these reactants. A scheme of redox catalysis is considered; according to this scheme ethylbenzene oxidation occurs as an ion-radical non-chain reaction.

19-24

Authors: T.S. Chmilenko, A.Yu. Chernyavska, I.Yu. Chernoivanenko, F.A. Chmilenko

The effect of cationic polyelectrolytes – copolymers of acrylamide with a charge density of 5 to 95% and a molar mass of 4106 to 8106 g mol-1 on the chemical-analytical properties of brompyrogallol red and its complex with molybdenum is studied. It is shown that the dye deprotonation is accelerated and the pH range of the complex existence extends in the presence of the polyelectrolytes. The values of deprotonation constant for brompyrogallol red in the absence and presence of polyelectrolytes are determined. Inorganic salts destroy a dye-polymer associate, whereas a ternary dye-polymer-metal complex is stable under these conditions. The compositions of an associate brompirogallol red–polymer and polymer–metal–dye complex compound are identified. It is established that the charge density of the polymer affects the composition of the associate dye–polymer and does not influence on the composition of the polymer–metal–dye complex. The ternary metal-polymer complex brompyrogallol red–polymer–molybdenum has been used as an analytical system for the determination of polymer in tap water in the concentration range of 0.4 to 8 mg l-1.

32-36

Authors: V.L. Budzinska

The influence of a reactive oligourethane-semicarbazide on the process of the structure formation in organic-inorganic composites based on sodium silicate and polyisocyanate is studied in this work. It is established that the formation of a system with oligomer containing urethane results in obtaining a branched oligomer with flexible polyester block. The change in the structure of the reactive oligomer results in enhanced physical-mechanical properties of the composite synthesized. Using the modifier proposed provides a fourfold increase in the tensile stress and a twofold increase in the elongation at break as compared with the initial composites. It is shown that the introduction of the modifier into the system of segmented oligomer leads to the formation of more homogeneous and denser structure. The presence of the modifier leads to a decrease in the size of silicate particles formed in such systems in situ. As a result of developed interfacial area, the structure of the composites becomes more homogeneous providing improvements in mechanical properties. The presence of reactive modifier in the structure of organic-inorganic composites allows reducing the curing time of the system to minutes instead of several hours.

40-46

Authors: Yu.S. Dzyazko, L.M. Rozhdestvenskaya, Yu.G. Zmievskii, Yu.M. Volfkovich, V.E. Sosenkin, V.V. Zakharov, V.G. Myronchuk, V.N. Belyakov, A.V. Palchik

Organic-inorganic membranes were obtained by the modification of heterogeneous cation and anion exchange polymer substrates with zirconium hydrophosphate and hydrated zirconium dioxide, respectively, the modifier content was 3.5 to 4.3% wt. The inorganic modifiers were found to be mainly in a form of single nanoparticles and their aggregates (up to 500 nm). The effect of the modifiers on the porous structure of the membranes was investigated using the data of standard contact porosimetry. Aggregated nanoparticles are a barrier against additionally sorbed electrolyte improving migration flux of counter-ions through the membranes and minimizing concentration polarization when the current is lower than its limiting value. This allows us to avoid the precipitation of insoluble compounds directly inside membranes. The electrodialytic desalination of milky whey was investigated; both pristine and organic-inorganic membranes were applied. The composites provide preferable removal of hardness and phosphorus-containing ions from whey; moreover, a higher desalination degree is reached. The current efficiency for inorganic ions reaches 89% under the optimal operation conditions which involve particularly a contact of one side of the organic-inorganic membrane with acidic solution.

55-59

Authors: V.V. Kazakov

The influence of the condensed matters structure on some physicochemical properties and performance attributes of a ruthenium-palladium catalyst (named as RPC-1) is investigated; this catalyst being reactivated by the action of acoustic and electromagnetic fields and used in cleaning of carbon(IV) oxide from impurities in the production of urea. A mathematical model is proposed which takes into account the combined influence of acoustic and electromagnetic fields on the process of heat transfer in the system "solid–liquid". The influence of the composition of the condensed matters and acoustic and electromagnetic fields on some physical, chemical and technical characteristics of the waste ruthenium-palladium catalyst RPK-1 is studied. It is shown that the application of electromagnetic and acoustic fields is promising on various stages of catalyst preparation. It is concluded that the heat transfer by a joint action of electromagnetic and acoustic fields may be intensified in the solutions of mineral acids more strongly than in the solution of acetic acid or alkali.

66-73

Authors: O.O. Lipko, M.V. Burmistr, Yu.M. Kobelchuk, O.I. Mikhaylova, L.I. Sula

Polymeric composite material of construction purposes is developed which is based on a new water-soluble diphenylolpropane formaldehyde adhesive and discrete fiber filler with a chaotic design of reinforcing. This material is distinguished by enhanced complex of physical-mechanical and tribotechnical properties. A water-soluble diphenylolpropane formaldehyde resin is used as adhesive; it is received using a two-stage synthesis. In the first stage, the synthesis occurs under the conditions of novolak condensation of diphenylolpropane with formaldehyde in the presence of an acid catalyst and excess of phenolic component; in the second stage, the synthesis proceeds under the conditions of resole condensation in the presence of an alkaline catalyst and excess of formaldehyde. The resin is a light yellow liquid with the dry residual of 43 to 45% wt; the content of free phenol being less than 1% wt. The filler is basaltic fibers of Ukrainian production with different cutting length. The surface tension of adhesive and filler was determined. The matrix was explored by the method of infra-red spectroscopy. The rheological properties of press materials, the temperature dependence of their viscosity, the degrees of filling, and the cutting length of fibers were determined. The optimal technological parameters of the processing of press materials were ascertained. In order to evaluate the adhesive interaction of the developed water-soluble diphenylolpropane formaldehyde adhesive with basaltic filler, some pattern models were made; it was stated that the obtained polymeric matrix is characterized by a higher durability and enhanced adhesive interaction with basaltic fibers compared with a matrix on the basis of previously developed water-soluble diphenylolpropane formaldehyde resin. Some physical-mechanical and tribotechnical properties of the developed materials were determined. The material is characterized by high environmental safety; it is able to work in the high-loaded friction units in corrosive mediums instead of imported textolite.

80-86

Authors: Kostyantyn M. Sukhyy, Elena A. Belyanovskaya, Irina V. Sukha, Elena V. Kolomiyets, Alina V. Gavrilko, Mikhaylo P. Sukhyy

A composite sorbents "silica gel/sodium acetate" synthesized by sol–gel method is investigated in this work. The composite structure is investigated by wide-angle X-ray scattering. The change of the adsorption properties of CH3COONa crystals is revealed to be resulted from their dispersion up to nanoscale. The sorption capacity of the composite "silica gel–sodium acetate" is stated to be 0.42 g/g that exceeds noticeably the linear superposition of the sorption capacity of the silica gel and sodium acetate mechanical mixture. The difference between water sorption kinetics for massive sodium acetate and for "silica gel/sodium acetate" composite is shown. The solar adsorptive chiller design is developed. Its operating characteristics are determined when "silica gel/sodium acetate" composite is used.

12-16

Authors: A.А. Zhigalovа, Y.E. Sknar, N.V. Amirulloeva, I.V. Sknar, V.I. Ovcharenko

The regularities of the electrodeposition process of Ni-P coatings are investigated. Uniform and smooth coatings of Ni-P alloy with a good adhesion to the substrate are obtained from a nickel methanesulfonate bath containing 0.03 to 0.12 mol/L sodium hypophosphite. The content of phosphorus in the coatings increases with an increase in the concentration of sodium hypophosphite in electrolyte. The established regularities are similar to those observed for the sulfate electrolyte. The nickel-phosphorus coatings deposited from both methanesulfonate electrolytes and sulfate ones are characterized by increased internal stresses which values increase with increasing concentrations of sodium hypophosphite in the bath. Nickel-phosphorus electrodeposits show enhanced microhardness values, their microhardness being increased with increasing concentration of sodium hypophosphite in electrolyte. Nickel-phosphorus coating exhibit a fine surface structure with small grains which are in close contact with each other. The brightness degree of Ni-P deposits measured relative to a silver mirror reaches 20% for the coatings electrodeposited from methanesulfonate electrolytes and is slightly lower than that in the case of sulfate electrolytes. The experimental data indicate that the Ni-P alloy electrodeposits obtained from methanesulfonate electrolytes exhibit enhanced physicochemical properties in comparison with the coatings deposited from sulfate electrolytes.

24-28

Authors: A.A. Kityk, D.A. Shaiderov, V.S. Protsenko, F.I. Danilov

The influence of NiCl26H2O additive to a deep eutectic solvent (DES) containing eutectic mixture of choline chloride and ethylene glycol (1:2) (i.e. a so-called Ethaline) on some physicochemical and electrochemical properties of obtained systems is examined in the present work. The density, viscosity, surface tension and electrical conductivity of the synthesized liquid mixtures (i.e. ionic liquids) are measured in the temperature range of 25 to 80 С. The calculation of the average radius of empty vacancies, or holes, in ionic liquids is performed. The introduction of nickel chloride into DES under consideration leads to a decrease in the value of the average radius of holes in the ionic liquid; as a result, the viscosity substantially decreases and the conductivity increases. The activation energies of viscous flow and conductivity are determined for the liquid mixture "choline chloride + ethylene glycol + nickel chloride hexahydrate" (1:2:1). Cyclic voltammogramms of a platinum electrode are obtained and analyzed for the systems "choline chloride + ethylene glycol", "choline chloride + ethylene glycol + water" and "choline chloride + ethylene glycol + NiCl26H2O". The electrochemical processes of cathodic electrodeposition and anodic dissolution of nickel are shown to proceed within the electrochemical window of the DES under consideration, i.e. they occur with a current efficiency of 100%.

35-41

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

The products of the interaction of tetra(butoxy)titanium and poly(butoxy)titanoxanes with acrylic acid have been synthesized and some their properties are described. The separated compounds are reddish-brown liquids or solid substances at room-temperature; they are very soluble in aromatic and chlorinated hydrocarbons, some of the products are soluble in aliphatic hydrocarbons and ketones. The structures of oligo(butoxy)titanium acrylates and poly(butoxy)titanoxanes are confirmed by elemental analysis, molecular mass measurements, IF spectroscopy and 1H NMR spectroscopy. The synthesis of the products under consideration is an equilibrium process and it is accompanied by secondary processes of the formation of butylacrylate and water as well as the condensation reaction induced by water. The achievement of the degree of substitution of butoxy groups in tetra(butoxy)titanium with acrylate groups of more than two is impossible under the reaction conditions, this is due to steric effects. As compared with tetra(butoxy)titanium, an increase in the distance between butoxy groups in poly(butoxy)titanoxanes results in a decay of the steric effects in the reaction with acrylic acid. The obtained products containing simultaneously reactive butoxy groups and acrylate groups linked with titanium atom can be further transformed as a result of hydrolysis, intereterification and polymerization of unsaturated bonds.

47-51

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

The electrocatalytic activity of Fe/TiO2 composite electrochemical coatings towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution (1 M NaOH) is investigated in this work. The composite coatings are obtained from methanesulfonate baths containing a certain amount of the dispersed phase of TiO2 nano-powder (P 25, Degussa, Evonik). The content of titania in composite coatings reaches to 5%. An appreciable acceleration of both hydrogen evolution reaction and oxygen evolution reaction is observed when TiO2 particles are incorporated into an iron matrix. The kinetics of HER and OER obeys the Tafel equation. The Tafel parameters are calculated and the probable mechanisms of electrochemical reactions are proposed and discussed. It is suggested that the electrocatalytic activity of composites is associated with an increase in the surface active sites on which some adsorptive stages of the electrochemical processes occur. In addition, the enhanced electrocatalytic activity of Fe/TiO2 composite can result from the formation of redox couple TiO2Ti2O3TiOOH.

56-62

Authors: R.V. Dinzhos, E.A. Lysenkov, N.M. Fialko

The effect of fabrication method (i.e. extruder mixing and ultrasonic dispersion) and the type of the filler (i.e. nano-sized silica and carbon nanotubes) on the thermophysical properties of nanocomposites based on polypropylene is studied using the method of differential scanning calorimetry. It is shown that the features of structure formation processes and the thermal properties do not depend on the fabrication method of nanocomposites and the type of the filler. The extremal character of the concentration dependence of the crystallinity degree and the melting point for nanocomposites based on polypropylene may be explained by the percolation processes of the filler particles. It is revealed a decisive influence of the nanoparticles surface on the thermal properties of polymer nanocomposites.

72-74

Authors: J.I. Mirzai, F.A. Hashimov, I.J. Ahmedova, F.B. Yusubov

The catalytic conversion of isobutene of high silicon zeolite catalyst in the H-form is studied in a temperature range of 150 to 450 ºC. A mathematical model for this process is developed by means of the experimental design method. The model considers the influence of temperature and volume velocity on the outputs of liquid and gaseous products of reactions. The results of chromatography and infrared spectroscopic analysis show that the liquid reaction products in the course of the conversion of isobutene at 150 to 250 ºC mainly include aliphatic hydrocarbons whereas at the temperature of 350 to 450 ºC they consist of aromatic hydrocarbons. Thus, liquid products include toluene and xylenes. Furthermore, it is stated that the catalyst activity is observed only after the accumulation of 6 to 8% condensation products on the surface of catalyst. It should be noted that the accumulated condensation products on the catalyst surface do not negatively affect the catalyst activity for a long time. Based on the developed mathematical model we performed the process optimization by computer simulation; a set of optimal parameters were determined.

79-85

Authors: I.S. Samchileev, A.N. Kalashnikova, N.V. Nikolenko, V.L. Kovalenko

The kinetics of the decomposition process of iron molybdate in a soda ash solution has been studied in a model loop reactor with a stationary solid phase. The study was aimed to optimize the recovery conditions of molybdenum. It was shown that the leaching process is limited by the stage of the diffusion of reactants ions through the iron hydroxide layer if the rate of solution flow is no less than 0.04 m/s. The concentration of molybdenum in all experiments increased with the duration and concentration of the soda ash leaching solutions. At the same time increasing the temperature in leaching process seems to have less influence on the molybdenum recovery than the concentration of soda ash solution. For the first time we derived an equation for the rate of a heterogeneous process in which the concentration of the leaching reagent is connected with the conversion rate of the solid reactant. The apparent activation energy of the soda ash decomposition of iron molybdate was calculated. On the basis of the analysis of experimental data we suggest that the key impact factors for optimization of the soda ash decomposition of iron molybdate are the size of the catalyst particles and the concentration of the leaching solution.

90-94

Authors: E.V. Smyrnova, N.D. Koshel

The aim of this study is to assess the possibility of obtaining information on the mechanisms and kinetics of processes occurring on iron-oxide electrode on the basis of potentiodynamic cycling. Voltage-current curves are registered on the iron plates in solutions KOH in a closed cell. The method of cyclic voltammetry can fully adequately characterize the features of charge-discharge processes on the electrode; it can be effectively used for the estimation of kinetic properties of different materials to use them as active masses in the power sources. It is shown that the alkali concentration significantly affect the form of a current-voltage curve which contains three main peaks. Two anodic peaks 1 and 2 correspond to the reactions Fe0  Fe2+ and Fe2+  Fe3+, respectively. Cathodic peak 3 is related to the cathode equivalent of reaction Fe2+  Fe3+. A few interdependent processes occur in the system with different equilibrium potentials; therefore the form of potentiodynamic curves depends on the width of potential cycling area. Deeper and comprehensive correlation with the functional properties of the materials in power sources may be obtained by combination of potentiodynamic investigation and the method of galvanostatic cycling.

103-11

Authors: V.V. Matveyev

The article describes the biography of Professor L.N. Sagoyan and highlights his scientific and educational achievements. His great contribution to the electrochemical science is closely connected with his work at the Department of Technical Electrochemistry and Scientific-Research Laboratory of Storage-Battery Systems of Dnepropetrovsk Institute of Chemical Technology (nowadays it is called Ukrainian State University of Chemical Technology). The main results of Prof. Sagoyan's investigations concern processes occurring on the nickel oxide electrode. He proved hydrogen transfer in the solid phase in the Ni(OH)2–NiOOH oxidation-reduction, he obtained data on semiconductor properties of these phases and their evolution in electrochemical reactions, he developed a model for the calculation of the dynamics redistribution of electrochemical process during charge-discharge, he also explained the nature of cobalt activating role.

9-16

Authors: O.Yu. Voskoboynik

The present article describes the synthesis and biological activity of series of 6-S- and 6-N-substituted 3-R-2H-[1,2,4]triazino[2,3-c]quinazolin-2-ones. It is shown that 3-R-2H-[1,2,4]triazino[2,3-c]quinazoline-2,6(7H)-diones cannot be used as starting materials for the synthesis of the target compounds, whereas the modification of potassium 3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-thiolates provides such an opportunity. The individuality of the synthesized compounds is proved by liquid chromatography–mass spectrometry and their structures by 1Н NMR, 13С NMR and mass spectroscopy. The characteristic signals in 1Н NMR, 13С NMR–spectra are described; the features of molecule fragmentation under electron impact are elucidated. The anticancer activity according to National Cancer Institute (USA) protocol is evaluated for some of the obtained compounds. The results of anticancer activity allow identifying a compound, which is capable of inhibiting the growth of ovarian cancer cells OVCAR-4 at 61.64%. The results of microbiological screening demonstrate that the synthesized compounds were inactive relative to E. Coli, show a moderate activity against P. aeruginosa and show very encouraging results in the study of antimicrobial activity against S. aureus and antifungal activity against C. albicans. The prospect of further research aimed at creating novel anticancer, antibacterial and antifungal agents based on the compounds described is herein discussed.

23-30

Authors: A.N. Zubko, V.I. Tkach

The interaction between the organic cation of thiamine (Тіа) with the heteropolyanion of 12-molybdophosphoric acid PMo12O403– was investigated in this work. The formation of a slightly soluble associate was confirmed by UV, IR spectroscopies and amperometric titration. The ratio of reactants was determined by the method of amperometric titration, the method being based on the reaction of the thiamin organic cation with the heteropolyanion of 12-molybdophosphoric acid PMo12O403–. It was stated that in the pH range from 2.0 to 5.5 the ratio of thiamin organic cation to heteropolyanion is 3 to 2 and the organic cation is doubly charged (Тіа2+). When the pH value is in the range from 6.0 to 8.0, the ratio of thiamin organic cation to heteropolyanion becomes 3 to 1 and the organic cation is singly charged (Тіа+). The associate of the thiamine organic cation with the heteropolyanion of 12-molybdophosphoric acid was used as an electroactive substance in a plasticized membrane of an ion-selective electrode which is sensitive to the thiamine cation. The effects of different plasticizers (dioctyl phthalate and dibutyl phthalate), variation in the content of the electroactive substance in the ion-selective electrode and the pH value on the slope of electrode function were studied. The linearity range of detectable concentrations was stated to be from 10-2 to 10-5 mol/l. The developed method of a direct potentiometric determination of thiamine organic cation both in aqueous solution of thiamine hydrochloride and in food bioactive additives is characterized by a high sensitivity (up to 10–5 mol/l), rapidity and accuracy.

35-41

Authors: N.V. Lutsenko, M.A. Mironjak, V.I. Tkach

The interaction between the organic cationic complex particle "glycyrrhizin-Ва2+" and heteropolyanion of Keggin structure РМо12О403- was investigated by spectrophotometric method. These slightly soluble associates were used as electrode active substances in plasticized polyvinyl chloride membrane ion-selective electrodes which are sensitive to the organic cationic complex particle "glycyrrhizin-Ва2+". Based on the experimental data, a new method for the potentiometric determination of glycyrrhizin both in industrial products and in roots of licorice extract has been developed. The method is characterized by a high sensitivity, selectivity and accuracy.

47-54

Authors: V.G. Vereschak, O.O. Pasenko, M.V. Salich

We analyzed the physicochemical processes of nanostructure formation of stabilized zirconia powders prepared by co-precipitation method. It has been established that scandium (III) precipitates in the same pH range as that of zirconium (IV). When preparing ZrO2 from co-precipitated zirconium scandium hydroxides, through their thermal dehydration two types of water molecules and two types of OH groups are formed in intermediate compounds. The number of high-temperature OH groups correlates with the number of additive ions which are localized near additive ions and form bridge OH groups. On the basis of a concept on zirconium (IV) tetrameric structure in solutions, a physicochemical model of nanoparticles formation in scandium (III) stabilized zirconia powders prepared by co-precipitation method has been proposed.

62-66

Authors: A.S. Krvavych, M.S. Kyrka, V.P. Novikov

In this work, we investigated the chemical composition of Gladiolus Imbricatus. The procedures of extracts preparation from different parts of the plant were developed. Chloroform extracts obtained in Soxhlet's apparatus were investigated using the method of gas chromatography-mass spectrometry (GC/MS). The analysis of extracts revealed the presence of 21 compounds; among them palmitic acid, lauric acid, oleic acid, myristin, eicosane, piperazine, nonacosane, farnesol, and spermidine were found to be present in the largest amounts. The identified compounds have a wide application in the cosmetic industry. They are used as plasticizers, emulsion stabilizers, and constituents in perfumery compositions. We have developed an industrial technology for producing the complex of biologically active substances (BAS) considering the main factors affecting the completeness and rate of the extraction. The percolation method was chosen to achieve the extraction of the maximum amount of BAS. The obtained extract may be used as a valuable raw material for the manufacturing of cosmetics and drugs.

78-82

Authors: O.V. Savvova, O.V. Babich

The mechanism of structure and phase formation of carbonate-apatite-containing glass-ceramic materials has been studied in this article, the performance properties of these materials have been determined. The system Na2O–СaO–ZnO–Al2O3–B2O3–P2O5–SiO2 was chosen as an initial one in which the compositions of model glasses with CaO:P2O5 ratio of 1:4 have been synthesized for obtaining carbonate-apatite-containing glass ceramic materials. The introduction of zinc oxide in an amount of 5 to 8 mol. % into the composition of calcium-silico-phosphate materials results in an intensive process of phase segregation. The phase segregation firstly exhibits the formation of nano- and micro- inhomogeneities in the structure; then formation of calcium phosphate nucleation is observed under cooling. Under the conditions of short-term thermal treatment, the fine structure is formed with a content of 50 vol. % of crystalline phases of calcium hydroxyapatite and calcium carbonate-apatite. According to the results of pilot tests, we have established that the mechanical properties of the obtained glass-ceramic materials meet the requirements of implants that can be used under variable loads of bone. The prospect of using the obtained bioactive glass-ceramic carbonate-apatite-containing calcium silicate materials as implants for bone endoprosthesis is confirmed on the basis of positive results of the clinical and biological tests.

10-18

Authors: A.I. Gladii, F.I. Tsiupko, Y.Y. Yatchyshyn, I.P. Polyuzhyn, M.M. Laruk

Polycarboxylates based on maleic monomers with a distant carboxylic group are applied as hyper plasticizers for concrete and demulsifiers for oil-water emulsions; they have rust-resisting properties too. These maleic monomers have two unsaturated bonds with different reactivity in addition to the distant carboxylic group. In the present communication, the kinetics of the non-catalytic and catalytic acylation of hydroxyethylmethacrylate and hydroxyhexapropylenoxyacrylate by maleic anhydride has been studied by means of acid number determination using conductometric titration. The experimental data are well described by the kinetic model of irreversible second-order reaction. The studies were conducted without solvents at a 10% molar excess of hydroxypolyalkylenoxy(meth)acrylate and at a concentration of triethylamine as a catalyst within the range from 0 to 4 mol. % of the initial concentration of maleic anhydride that is suitable for the implementation of an industrial process. The optimal conditions for the synthesis of two monomers are as follows: the temperature is 363 К or 353 К, the reaction time is 0.5 or 2 hours at catalyst concentration of 4 mol. % of the initial concentration of maleic anhydride. A kinetic compensation effect was observed for the activation energies and pre-exponential factors calculated by the Arrhenius equation. The structures of the purified synthesized monomers have been confirmed by refractometric method and IR spectroscopy.

23-37

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

The presence of ionic dopants in the electrolyte inhibits the process of PbO2 electrodeposition in the kinetic region due to adsorption of ionic additives on the growing oxide surface. In this case, the addition of fluoride ions increases the deposition current in the diffusion region by increasing the contribution of migration component. The ion-doped oxide forms in the presence of additives in the electrolyte. The content of additives in the deposit varies between 0.2 to 4.2% (wt.) depending on the additive nature, its concentration and deposition conditions. Lead dioxide deposited from methanesulfonate electrolytes at room temperature is a mixture of α- and β-phases, and the content of the latter does not exceed 4.2% wt. Temperature growth and the addition of doping ions in the electrolytes lead to an increase in the β-phase content in the coating. Increasing the deposition potential and decreasing the electrolyte's pH lead to the growth of crystals size and the appearance of priorities in the crystallographic orientation. The content of crystals with orthorhombic lattice is proportional to the charge consumed in the formation of two-dimensional nuclei.

45-49

Authors: T.P. Rebrova, V.L. Cherginets

Europium dihalides are used as dopants in optical luminescent crystals grown from molten media. Oxygen-containing admixtures existing in the melt react with Eu2+ cation that can result in oxide precipitation and loss of the activator. To estimate the possibility of running similar processes the data on solubility and dissociation of EuO in halide melts are necessary. It is of interest to trace the effect of halide melt composition on oxide solubilities. Solubility product (6.3∙10-9 mol2∙kg-2) and dissociation constant (6.0∙10-6 mol∙kg-1) of EuO in molten NaBr-NaI (0.8:0.2) mixture are determined by a potentiometric titration method with the use of membrane oxygen electrode. Total concentration of ionic (Eu2++O2 ) and undissociated (EuO) forms in the saturated solution is equal to 1.15∙10-3 mol∙kg-1. In comparison with NaI melt, the concentrations of Eu2+ and O2 in the saturated solution increase by 25 per cent whereas the concentration of undissociated EuO and the total content of europium in the saturated solution of EuO decrease by 30 per cent. An increase in the dissociation degree of europium monoxide in bromide-iodide melt as compared with the iodide can be explained by the presence of harder base (bromide) in the former melt. The reduction of EuO concentration in the mixed melt is explained by a decrease in the melt of a number of holes appropriate for EuO by size as compared with the pure iodide.

55-62

Authors: V.D. Barsky, G.A.Vlasov, А.А. Pivovarov, A.V. Kravchenko

With the use of the model of metamorphism dynamics, the authors theoretically and experimentally show the "leaps" of metamorphic restructuring of fuel, and determine the character of changes in the ratio between chemical bonds of different nature. The report provides, on this basis, generalized concept according to which the dynamics of intermolecular binding in solid fuel is determined by outrunning reduction of the role of EDA-interactions and hydrogen bonds. Minimum strength of supramolecular structure arising in connection with it falls on the stage of coking coals. Models of averaged "molecules" of solid fuel are offered which characterize its chemical composition during the periods of revealed "leaps" of metamorphism. Adequacy of these models is confirmed by stoichiometric equations of reactions behavior, material balances of stages and compatibility of combustion values of model substances and coals of close elemental composition. Basic provisions of the developed theory on chemistry of the process of metamorphism were used in estimation of the chemical potential of coals, as well as during comparative assessment of primary reserves of coal, oil and gas: 87.05%, 4.92% and 8.03% (mass percent), accordingly, which differs significantly from data published earlier (95% of coal and 5% of oil and gas).

66-72

Authors: T.L. Rakitskaya, T.A. Kiose, K.O. Goludchik, L.P. Oleksenko, R.M. Dlubovskii

Natural clinoptilolite (Sokirnitsa, Transcarpathian region, Ukraine, hereinafter called as N-CLI) was thermally (by heating at 300 C, hereinafter called as 300-CLI) and hydrothermally (by boiling in distilled water, hereinafter called as H2O-CLI) activated. The modified and natural samples of clinoptilolite were further used as supports (S) for obtaining K2PdCl4-Cu(NO3)2-KBrS systems by impregnation of each support with the mixed aqueous solution of these compounds at their certain ratio followed by drying at 110 C till constant weight. The systems anchored were tested as catalysts for the reaction of low-temperature carbon monoxide oxidation. The comparison of the catalytic activities of these systems with the supporst properties characterized by X-ray phase analysis, IR spectroscopy, thermogravimetric analysis, and ad/desorption of water vapor showed that the modification of clinoptilolite was resulted in slight changes in its structure without any damage of its framework. Evidently, a dramatic improvement in the catalytic behavior of K2PdCl4-Cu(NO3)2-KBr300-CLI system was due to the significant increment (actually, twice) in 300-CLI surface area compared with N-CLI and H2O-CLI as a result of the complete zeolite water removal. It was accompanied by the heightening in a number of accessible Al(ОН)Si and Si-O-Al structural fragments which were the sites of formation of catalytically active surface palladium-copper complexes.

79-85

Authors: U.V. Khromyak

In this work, we synthesized copolymers of polyvinylpyrrolidone with methyl methacrylate by means of emulsion polymerization. The formation of graft copolymers of polyvinylpyrrolidone is confirmed on the basis of IR-spectroscopic studies. The nature of monomer, concentration and temperature significantly affect the effectiveness and the degree of grafting. The synthesized copolymers have been used as polyvinylpyrrolidone polymer matrixes to produce methyl methacrylate–copolymer compositions which are cured by the block polymerization. The polymerization of methyl methacrylate occurs with at a high speed, and the degree of monomer conversion reaches 65 to 95% for 10 to 15 minutes depending on the ratio of the components. The highest rate of polymerization and the maximum degree of conversion are observed if the ratio between the polymer matrix and methyl methacrylate is equal to 2:1. The obtained materials are distinguished by enhanced performance properties such as hardness, heat resistance, adhesion to various substrates, water absorption, and chemical resistance in acidic and alkaline media.