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

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.