(Vestsi Natsiyanalnai Akademii Navuk Belarusi)
SERIES OF CHEMICAL SCIENCES
Published by The Belaruskaya Navuka Publishing House, Minsk, Republic of Belarus
| Proceedings of the National Academy of Sciences of Belarus (Vestsi Natsiyanalnai Akademii Navuk Belarusi) SERIES OF CHEMICAL SCIENCES Published by The Belaruskaya Navuka Publishing House, Minsk, Republic of Belarus |
Summary: A process of a film growth during chemical deposition of gold from dicyanoaurate-hypophosphite solutions on a surface of nickel coatings has been investigated by electrographic and ESCA methods. Electroless gold deposition has been shown to be retarded due to passivation of a surface with insoluble AuCN and oxidation of catalytically active nickel surface and to terminate at the film thickness of 4 µm.
Summary: Data on a size (< 4 nm), a shape (mostly edged) and a crystal structure (cubic zinc blends for 3 of 4 cluster samples) of CdTe nanoclusters prepared through a wet chemical route using 2-mercaptoethanol and 1-thioglycerol as stabilising agents were obtained by X-ray diffractometry and high resolution transmission electron microscopy.
Gaponik N.P., Shchukin D.G., Kulak A.I., Sviridov D.V.
Microheterogeneous photocatalytic systems based on polyaniline-modified ferric (III) oxide. pp. 16--20
Summary: Synthesis methods have been elaborated for microheterogeneous colloidal photocatalysts of "core-shell" type based on a-Fe2O3 modified by polyaniline. The catalysts synthesized afford an effective SO2 conversion into sulphate in an aqueous media. A nature of limiting stage of the photocatalytic process has been elucidated as a result of electrochemical modelling of its oxidative and reductive components as well as direct photochemical measurements in the colloid under irradiation. The ways of the photocatalytic system optimization by polyaniline shell doping with heteropolytungstate-ions have been proposed.
Ivanova N.P., Kapitsa M.S., Zharskii I.M.
Electrodeposition of corrosion resistant nickel coatings in pulsing mode of electrolysis. pp. 21--24
Summary: Corrosion resistance of nickel coatings prepared in sulphate and acetate-chloride electrolytes under direct and pulsing current has been evaluated by a contact current technique. Pulsing current has been shown to decrease Ni-coating thickness by 1 -- 4 µm and save 8.9 g/m2 µm of nickel.
Bondareva G.V., Rat'ko A. I.
Chromium (VI) adsorption on a modified carbon fibrous adsorbent. pp. 25--29
Summary: An absorbability of the initial and modified relative to Cr2O72--ion carbon fibrous adsorbent (CFA) has been investigated. The initial CFA has been shown to adsorb up to 82 mg/g of Cr(VI), while that figure for the modified CFA equals to 105 mg/g. A conclusion has been drawn based on kinetic curves analyses that ion-exchange process being carried out in deluted solutions of K2Cr2O7 is realyzed by an outside diffusion mechanism.
Siderko V.M., Teplyakova O.A., Shevchuk T.A., Kulinkovich O.G.
A dependence of cloud point of poly(N-isopropylacrylamide) water solutions on concentration of organic and inorganic salts. pp. 30--33
Summary: Organic and inorganic salts have been shown to deteriorate at a small concentrations a mutual compatibility of polymer with water. A temperature of phase transition rises at a salt concentration of about 10-3 mol/l. An effect of organic and inorganic salts on cloud point of poly(N-isopropylacrylamide) water solutions has been studied. An influence of a third component on a polymer phase transition in water has been explained in terms of macromolecule hydration.
Sen'kov G.M., Nikitina A.M., Yakubenko V.M.
Changing of properties of catalyst of raffinate reforming during work. pp. 34--37
Summary: A chemical composition and reaction properties of a catalyst for unsaturated hydrocarbons hydrogenation have been investigated after a longduration work. The chemical composition has been shown to be unchanged, while a complete regeneration of catalytic properties is possible as a result of oxidative regeneration.
Sokolovskii A.E.
A study of liquid-vapour equilibrium in the systems of ZnMe2--CdMe2 and ZnMe2--GaMe3. pp. 38--43
Summary: A vapour pressure of binary systems of ZnMe2--CdMe2 and ZnMe2--GaMe3 has been measured by a static method with a membrane zeromanometer. Thermodynamic parameters of the evaporation have been determined. A vapour phase composition and activity coefficients have been calculated using Wilson equation.
Komarov V.S., Repina N.S., Karpinchic E.V.
An effect of ultrasound, SAS and drying conditions on Al2O3 Structure. pp. 44--48
Summary: Physical and chemical principles of Al2O3 porous structure formation dependence on a hydrogel ultrasonic treatment in the presence of surfactant and under conditions of drying have been elaborated. The ultrasonic treatment in the presence of surfactant has been shown to displace a structure of the samples synthesized in a microporous sphere. A sublimation dry of hydroxide has the same effect. Reasons and mechanism of such effects as ultrasound, surfactant and drying conditions on the process of structure formation, enhance of specific surface and sorption volume are discussed. The methods proposed show promise as preparation methods for adsorbents and ultra disperse detergents which are raw materials for ceramics synthesis.
Komarov V.S., Repina N.S., Shavel A.I.
Activation of natural alumosilicates by bicomponent acidic solutions. pp. 49--53
Summary: An acidic activation of natural alumosilicates by bicomponent acidic solutions has been shown for the first time. The acidic activators consist of 20 % solution of H3PO4 and 20 % solution of HCl, HNO3 or H2SO4. An effectiveness of clays activation has been shown to be the highest in the presence of HCl and slightly lower in the presence of HNO3 or H2SO4. A sorption capacity and a specific surface of the samples activated by bicomponent acidic solutions are higher than these for the samples activated by individual acids. An interpretation of the activation mechanism is given.
Summary: Dehydrobromination of 3-carene-dibromocarbene adduct has been established to be accompanied by an arrangement resulting in unsaturated hydrocarbon with an eight-membered cycle and monobromide with a carene skeleton. If the conditions of carbene synthesis facilitate a dehydrobromination of the adduct, monobromoderivatives of cycloheptatriene would be the main reaction products.
Pritytskaya T.S., Kel'in A.V., Sorokin V.L., Kulinkovich O.G.
Synthesis and polymerization of derivatives of dithienylfuran, terthiophene and dithienylpyrrole. pp. 60--65
Summary: Synthesis of substituted dithienylfurans, terthiophenes and dithienylpyrrols with alkyl substituents in one of the five-membered cycle is described as well as polymerization of the substances synthesized under effect of aqueousless FeCl3 Elecroconductive properties of the polymers prepared have been atudied.
Oparin D.A., Khobets S.E., Solodunov A.A.
l-Ethylthio-3,3-diaryltiophthalylium salts in reactions with amines. pp. 66--69
Summary: Primary amines have been shown to react independently of their structure with 1-alkylthio-substituted thiophthalylium salts unambiguously on a-carbom atom of a hetero-ring followed by elimination of alkylmercaptane and formation of iminothiophthalane derivatives.
Summary: A chemical modification of a cell surface (biotinylation of erythrocyte plasma membrane proteins) has been shown not to alter thyroxin-binding properties of the receptors. A resistance of membrane prooxidant-induced haemolysis and activities of protectin system enzymes are also unchanged. It was found thal a direct physical adsorption of streptavidin on a plastic surface decreases a cell binding as compared to a biospecifically mediated coating.
Summary: Mixed nitrosulphoesters of dextran have been synthesized by a consequent nitration of polysaccharides in mixtures of nitric and phosphoric acids and phosphoric anhydride and by sulfation of nitroesters in sodium pyrosulphate (Na2S2O7) -- dimethyl sulphoxide (DMSO) system. An effect of nitrating and sulphating mixtures composition, temperature and sulphating reaction time on a content of functional groups and intrinsic viscosity of nitrosulphoesters of dextran has been studied. Water-soluble nitrosulphoesters of dextran with a degree of nitro groups substitution in the range of 0.3--0.7 and intrinsic viscosity of 0.18--0.04 possess a combined anticoagulant and antiaggregate activity.
Summary: Transport characteristics of different UV-membranes of MIFFLIN type have been studied during ultrafiltration of model water-alcohol solutions as well as waste technological media, obtained during fractionating of blood plasma. A treatment of membranes with 20% ethanol solution has been established to result in a substantial increase of their productivity, an effectiveness of treatment depends on an initial permeability and a composition of polymer matrix. A technological process has been developed of regeneration of protein alcohol solution of blood plasma.
Volozhin A.I., Osmolovskaya L.Yu., Rozmyslova A.A.
High temperature synthesis of filmforming polyimides based on 1,2,3,4-cyclopentantetracarboxylic acid dianhydride and aromatic diamines. pp. 87--90
Summary: Cycloaliphatic polyimides based on 1,2,3,4-cyclopentantetracarboxylic acid dianhydride and aromatic diamines have been obtained by one-step catalytic polycondensation of monomers in m
-cresol solution at 180--190 °C with catalytic amount of some tertiary amines. Optimal conditions of soluble polyimides synthesis and film preparation on their base have been selected. Polyimide films prepared have been characterised by mechanical and thermal properties.
Kaputskii F.N., Mardykin V.P., Gaponik L.V., Milchanina T.L.
Oligomerization of C9 fraction of liquid products of benzine pyrolysis on a cationic catalyst. pp. 91--92
Summary: Result of oligomerization of C9 fraction of aromatic hydrocarbons in the presence of a complex cationic catalyst (aluminium trichloride etherates) are presented. Optimal parameters of hydrocarbon resins synthesis for varnish-paint materials have been determined.
Bodrykh T.I., Stepanova L.I., Sviridov V.V.
On a possibility of film preparation of Ni -- Ag alloys by successive deposition of Ni metals. pp. 93--97
Summary: A possibility of film preparation of Ni -- Ag alloys by successive deposition of Ni and Ag layers has been investigated. Thermal treatment at 100--200 °C of the samples obtained by silver deposition, which were two-layer system in an initial state, has been shown to result in silver diffusion into nickel and appreciable equalisation of a composition. Data on phase composition and some regularities of diffusion process in these alloys have been obtained.
Levitskii I.A., Biruk V.A., Chernyak A.P., Pavlukevich Yu.G.
Investigation of kaolins of the Republic of Belarus to evaluate a possibility of their application in production of ceramic goods. pp. 98--102
Summary: Natural kaolins of the Republic of Belarus are not homogeneous by their chemical composition and size distribution. They are characterized by a high content of dye-stuff oxides and that of alkaline metals. An enrichment process substantially increases their quality. A possibility has been shown to use the natural kaolins as components for production of ceramic tiles of different types, while the enriched kaolins show promise as components for hygiene ceramic goods.
Vorob'ev N.I., Teterevkov A.I., Zyk V.V.
Extraction of rare earth elements from phosphogypsum with sulphuric acid. pp. 103--106
Summary: An extraction degree of rare earth elements-, fluorine- and phosphorus-containing compounds from phosphogypsum under conditions of sulphuric acid treatment has been investigated as a function of a solution strength, temperature and a circulation factor. Maximal extraction degree accounts for about 30% of lanthanides, 50--70% of phosphates and 70 -- 80% of fluorides. The extraction degree of compounds containing rare earth elements has been found to decrease with increasing number of solution cycles. On six cycles a composition of liquid becomes constant. With a cycle number increase variation of a composition of liquid are insufficient and does not exceed 1.0 g/l (rare earth elements), 10.5 g/l (phosphorus pentoxide) and 1.9 g/l (fluorine). As a result of the extraction a concentration of fluorine- and phosphorus-containing compounds in the washed phosphogypsum falls to a level of 0.1 and 0.5%, respectively. All this permits for phosphogypsum to be used in filling material production and as a medical gypsum without further purification.
Grozhik V.A., Bychko G.V., Khodskii L.G.
Peculiarities of corrosion process of thin films of leadborate and leadborosilicate glasses. pp. 107--111
Summary: An effect of chemical composition of thin glass films on their corrosive resistance and other properties has been found by IR-spectroscopy and X-ray phase analysis to hastochastic nature inlike bulk glasses. This peculiarity should be taken into account at practical application of thin glas films.
Chernikova G.P., Agabekov V.E., Gal'china G.P., Shibaeva L.V. †
Water soluble thin film organic material for enhancing contrast in photolithography. pp. 112--115
Summary: A water soluble material based on steryl pyridine and polyvinyl alcohol has been worked out to enhance contrast in a lithography process using naphthoquinone-novolac photoresists.
Summary: A distribution of some heavy metals (Zn, Cu, Pb, Cd) in cow milk in Belarus has been studied depending on season variation and territories. A main pollutant is Pb and its average content is above permissible contamination limited for milk and milk products. There are some anomalies for Cd and Zn but in the most cases a content of these elements as well as Cu in milk is safe for consumption.
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