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.