Весці Нац. акадэміі навук Беларусі. Сер. хім. навук, 2005, No.3
/ Выданні акадэміі / Навуковыя часопісы
Весці Нац. акадэміі навук Беларусі. Сер. хім. навук, 2005, No.3
| Весці Нацыянальнай акадэміі навук Беларусі
СЕРЫЯ ХІМІЧНЫХ НАВУКВыдавец: Беларуская навука, Мінск, Рэспубліка Беларусь |
Нумар 3, 2005
ЗМЕСТ
АНАЛІТЫЧНАЯ ХІМІЯ
Rakhman'ko E. M., Tsvirko G. A., Bogdanovich Yu. V.
Influence of quaternary ammonium salt exchange center steric accessibility on extraction of bromide cadmium complex. pp. 5--8.
Summary: The influence of nature of quaternary ammonium salts (QAS) with varied contents of methyl groups on cadmium extraction from bromide mediums has been investigated. The cadmium complex affinity to anion-exchanger is shown to be strongly influenced by the number of methyl substituents at QAS nitrogen atom. It has been established that introduction of more methyl groups into QAS cation results in dramatic improvement of its affinity to double-charged bromide cadmium complexes, as compared to hydrophobic organic anions. The most effective cadmium extractant is QAS with three methyl groups at the quaternary nitrogen atom.
КАЛОІДНАЯ ХІМІЯ
Komarov V. S., Repina N. S. †, Rat'ko A. I.
Structure of activated natural aluminosilicates modified by organic acids. pp. 9--11.
Summary: Alkaline activation of meta-kaolinite and montmorillonite by mixture of CaO and NaCl with subsequent neutralization of activating solution with organic acids has been studied. It has been shown that with the increase of acid molecular mass, more macroporous adsorbents with high sorption capacity and specific surface are formed. Structural parameters of such modified organic-mineral samples enhance after their thermal treatment. Sorption volume improvement is in cymbate relationship with molecular mass of modifying acid. The mechanism for structure formation of the samples in presence of organic acids has been proposed.
Luksha O. V., Krut'ko N. P., Opanasenko O. N., Ovseenko L. V.
Influence of ethylene vinyl acetate and butyl acrylate copolymers on structural and rheological properties of oxidized bitumens. pp. 12--18.
Summary: Influence of copolymers of ethylene and vinyl acetate (EVA) or ethylene and butyl acrylate (EBA) on properties of oxidized bitumen is investigated. It has been shown that with increase of vinyl acetate or butyl acrylate content and branching degree, the polymer becomes more capable of interaction with bitumen and of polymeric net formation in bitumen matrix. This is accompanied by increase of tensile strength and visco-elastic properties of polymer-bitumen compositions based on those polymers. The optimal results of modifying of the oxidized bitumen with copolymers of EVA and EBA are reached at their concentration of 5--7%. The similar course of change of rheological properties researched polymer-bitumen compositions is caused by a similar chemical structure of investigated copolymers.
Investigation of relationship between speed of shift and dynamic viscosity, as well as temperature and dynamic viscosity, as compared to standardized methods, allows prediction of the material behavior under real conditions of preparation and use of polymer-bitumen compositions.
Komarov V. S., Repina N. S. †, Rat'ko A. I.
On the mechanism of alkaline activation of clays. pp. 19--22.
Summary: The mechanism of alkaline activation of meta-kaoline and Tomashkovskii montmorillonite has been discussed. It has been shown that, in the first case, a zeolite of A type and, in the second case, sodalite is formed. Sorption and structural properties of obtained samples have been studied. It has been found that during acid neutralization of after-activation solution, highly active amorphous adsorbents are formed. On the contrary zeolite-contaning adsorbents with high adsorption potential at low and medium p/ps values are formed if zeolite is isolated from activation solution; hydroxide is precipitated, washed and mixed together with zeolite.
ФІЗІЧНАЯ ХІМІЯ
Bychkova V. A., Kuvaeva Z. I.
Hydrolysis of arnino acids compound salts. pp. 23--27.
Summary: The degree of hydrolysis for compound salts of amino acids (arginine aspartate, arginine glutamate, lysine aspartate, lysine glutamate and ornithine aspartate) in their 0.1 M aqueous solutions have been calculated. All the examined salts have been shown to have low hydrolysis degree (no more than 0.35%) and narrow range of pH values (6.15--6.70) of their aqueous solutions. The equations for describing relationships between pH and hydrolysis degree for compound salts of amino acids have been suggested. It has been demonstrated that hydrolysis degree of these salts remains low in wider range of pH (5.0--8.0) as well.
Shevelyova M. P., Kabo G. Ya., Maksimuk Yu. V.
Enthalpy of formation for 2-(1-hydroxycyclohexyl)cyclohexanone. pp. 28--32.
Summary: The enthalpy of formation for 2-(l-hydroxycyclohexyl)cyclohexanone has been measured using a bomb calorimeter: Dr H0m (cr, 298.15) = -597.63 ± 2.42 kJ • mol-1, Df H0m (liq, 298.15) = -577.31 ± 2.42 kJ • mol-1 (the latter being obtained from the heat capacity data and the enthalpy of fusion). Enthalpies of autocondensation for cyclohexanone and of dehydration reaction for 2-(l-hydroxycyclohexyl)cyclohexanone were calculated and compared with the dehydration enthalpy for 1-methylcyclohexanole.
Vashina V. G., Murashkevich A. N., Zharskii I. M.
Controlling of structural characteristics of silica gels on various steps of the sol-gel method. pp. 33--38.
Summary: Porosity and structural properties of silica obtained by sol-gel method have been studied by BET using nitrogen adsorption, benzene adsorption under static conditions, and with "Fritch" laser analyzer.
Fen'ko L. A., Bil'dyukevich A. V.
Phase diagram of polycaproamide -- dimethylformamide -- lithium chloride system. pp. 39--41.
Summary: The phase diagram of the polycapramide -- dimethylformamide -- lithium chloride system have been built using the cloud points method and spectroturbidimetry titration. Areas of thermodynamically stable compositions as well as amorphous separation, gel-like state and phase separation accompanied by crystallization of the polymer and lithium chloride solvate with stoichiometric ratio of DMF:LiCl = 4:1, have been determined.
Rabchynski S. M., Ivanov D. K., Streltsov E. A.
Photoelectrochemical method for preparation of CdSe nanoparticles. pp. 42--45.
Summary: Colloidal CdSe nanoparticles with average particle size from 40 to 80 nm were synthesized by the photoelectrochemical technique using Se electrode precursor. Colloidal particles were formed as the result of Cd2+ ions interaction with H2Se generated photoelectrochemically. The formation of metal selenides was observed both at the Se-cathode surface and in the electrolyte. At metal concentration below 0.01 mol-1 metal selenide colloidal particles were negatively charged because of HSe~ anion adsorption and this favoured the evacuation from the electrode surface into the solution. At Cd2+ concentration above 0.01 mop-1, selenide particles were positively charged because of Cd2+ adsorption and this resulted in attraction of the particles to the negatively charged electrode preventing colloidal solution formation. Thus, varying the metal ion concentration provided the means of controlling the photoelectrochemical reaction. The similar approach was successfully applied for In2Se3 and ZnSe colloidal nanoparticles.
Prigozhaeva L. M., Polikarpov A. P., Shunkevich A. A., Soldatov V. S.
Influence of small additions of bifunctional comonomers on the reaction of graft copolymerization of acrylic acid on the polypropylene fibers. pp. 46--49.
Summary: The influence of small additives of bifunctional comonomers (ethylene glycol dimethacrylate, methylene bis-acrylamide and divinylbenzene) on the process of radiation graft copolymerization of acrylic acid on the pre-irradiated polypropylene fibers has been studied. The dependence of graft copolymerization parameters (the graft level and conversion of the monomer, effectiveness of graft copolymerization) upon the type of comonomer at 284 K and 353 K has been analyzed.
Kolyago A. E., Rakhmanov S. K., Sergeeva O. V., Stashonok V. D.
Formation of silver nanoparticles in photographic layers means of redox dispersion method. pp. 50--56.
Summary: Methods for obtaining silver nanoparticles using redox treatment of AgBr chemical reduction product in real and model photosensitive layers have been proposed, based on chemical dispergation of microsized silver particles and their conglomerates in polymeric matrix (gelatine, polyvinyl alcohol). The possibility to change shape, mutual arrangement and granulometric composition of silver nanoparticles, setting the given value for their size (from 2 to 200 nm), by varying silver contact time with redox solution, treatment conditions and concentration of solution components is demonstrated.
АРГАНІЧНАЯ ХІМІЯ
Petkevich S. K., Potkin V. I., Nechai N. I., Vashkevich E. V., Kaberdin R. V.
Synthesis of N-acyl substituted 2-(l-nitro-2,3,3-trich!oro-2-propenylidene)-oxazolidines and imidazolines. pp. 57--59.
Summary: The corresponding N-acyl derivatives were obtained by the reactiion of 2(1-nitro-2,3,3-trichloro-2-propenylidene)-oxazolidine and -imidazolidine with acetyl chloride and benzoyl chloride in the presence of pyridine. In the reaction with imidazolidine, both amino groups of the heterocycle participated.
Dikusar E. A., Yuvchenko A. P., Kozlov N. G., Kadutsky A. P., Olkhovik V. K.
Method of preparation for salts of 4,4'-biphcnyldicarboxylic acid with amines and triphenylphosphine. pp. 60--64.
Summary: A method of preparation for salts of 4,4'-biphenyldicarboxylic acid with amines and triphenylphosphine has been described.
Tarasevich V. A., Basalaeva L. I.
Synthesis of 5-amino-4-hydroxy-3-[methoxy-(4-sulphophenyl)azo]phenylazo]-2,7-naphtalenedisulphonic acid sodium salt. pp. 65--66.
Summary: Sodium salt of 5-amino-4-hydroxy-3-[methoxy-(4-sulphophenyl)azo]phenyIazo]-2,7-naphtalenedisulphonic acid was synthesised by stepwise diazotization of sodium sulphanilate with o- or p-anisidine and then with 5-amino-4-hydroxy-2,7-naphtalene disulphonic acid.
БІЯАРГАНІЧНАЯ ХІМІЯ
Drozhdenyuk A P., Kolomiets E. I., Zdor N. A, Romanovskaya T. V., Epshtein If. V., Dubovskaya L. V., Vashkevich I. I., Sviridov O. V.
A new method for purification and quality control of Streptavidin. pp. 67--72.
Summary: The laboratory technology of Streptavidin preparation from the cultural fluid of Streptomyces avidinn by a non-chromatographic method has been described. The method includes partial removal of contaminating proteins and pigments with calcium fluoride gel and the successive precipitations of streptavidin-containing protein fraction from the supernatant with ammonium sulfate and iso-propanol. The yield of Streptavidin was about 70%, and the purity of the final product was no less than 95%. The analytical modification of the same procedure may be used for the assessment of Streptavidin content in the cultural fluid. Bimolecular binding to solid-phase immobilized biotin and to biotinylated peroxidase from the solution was utilized for quantitative determination of biologically active polyvalent Streptavidin. An oligonucleotide probe containing biotin and fluo-rescein residues at its opposite ends was used for testing Streptavidin coated microplates designed for genodiagnostics studies. Tubes with immobilized Streptavidin were controlled against the preset quality parameters for solid-phase radioimmunometric assay.
Andrianov A. M.
Structure and conformational properties for HIV-MN GP120 V3 loop. pp. 73--82.
Summary: Secondary structure elements and conformations of irregular stretches for the HIV-MN GP120 V3 loop, including the virus immunogenic crown as well as the sites liable for cell tropism and cell fusion, were determined using the theoretical method developed previously. Computations based on the published data of NMR spectroscopy in water and in water/trifluoroethanol mixture point out that, in the first case, V3 loop N-terminal segment 1--14 exhibits the extended conformation whereas its C-terminal stretch 21--35 takes an unordered structure. A double p-turn IV-IV was revealed in water in central V3 loop region 15--20 which determines the specificity of virus binding with neutralizing antibodies. The addition of trifluoroethanol was shown to result in substantial altering of the HIV-MN V3 loop secondary structure. For instance, extended segment 1--14 develops into irregular site but C-terminal fragment 24--31 transforms into helix 310. The structural rearrangements occur also in stretch 15--20, producing the more compact, as compared to water, spatial fold of the main chain. On the basis of comparative analysis, statistically significant differences were found for the local structures of the HIV-MN V3 loop in water and in water/trifluoroethanol mixed solvent.
ГЕАХІМІЯ
Akudovich S. A.
Trace elements of highly mineralized brines of Pripyat Trough. pp. 83--86.
Summary: Data of the trace element composition, concentrations and distribution peculiarities (Ag, Al, Ba, Be, Bi, Co, Cr, Cu, Ge, Mn, Mo, Ni, Pb, Sb, Ti, Tl, V, Y, Yb, Zn, Zr) in subsurface brines of the Pripyat Trough have been presented. Several techniques of quantitative and semi-quantitative atomic emission spectral analysis of trace elements in highly mineralized (200--460 g/l) brines, as well as the technique for estimation of the average values in the case of imperfectly determined distributions, have been discussed.
ТЭХНІЧНАЯ ХІМІЯ І ХІМІЧНАЯ ТЭХНАЛОГІЯ
Basiniuk E. V., Zhukow V. K.
Willow using activated carbons preparing. pp. 87--90.
Summary: It has shown a possibility of getting high-quality activated carbons on the basis of natural and modified willow by the steam activation method. The values of sorpting pores are 0.53 and 0.65 cm3/g and specific areas -- 760 and 1181 m2/g accordingly.
Mozheyko F. F., Dikhtievskaya L. V., Goncharik I.I.
Physico-chemical properties of galite waste. pp. 91--93.
Summary: Physico-chemical properties of galite waste have been investigated. The ways of purposeful regulation of their properties for use of galite waste as a component of complex fodder addition for cattle was shown.
Tereshchenko I. M., Popov P. Yu.
Ways of energy consumption reduction for cordierite production. pp. 94--97.
Summary: Using unconventional raw materials and introduction of fine cordierite cake makes it possible to boost sintering and cor-dierite formation processes. As the result, conditions are created for low temperature (1180-- 1200°C) cordierite synthesis, the products being reasonably stable thermally and mechanically.
Production based on materials designed can be used in electrical industry, engineering and chemical industry, as well as in production of refractory and construction materials.
Bobkova N. M., Barantseva S. E., Kravtchuk A. P., Login V. G., Kononovich V. M., Shostak L. M.
Peculiarities of crystallization for glasses based on diabaze-granite mixture. pp. 98--102.
Summary: Peculiarities of crystallization for glasses based on diabaze-granite mixture have been studied. The possibility for synthesis of rock glass-ceramics with highly desirable physical and chemical properties have been substantiated.
Fleisher V.L., Lamotkin A.I.
Study of abietic acid and amino alcohols reaction products thermal stability. pp. 103--105.
Summary: Thermal destruction of amide and ester bonds in products of abietic acid reaction with mono-, di- and triethanolamine, as well as tall oil and rosin with monoethanolamine have been studied by differential thermal analysis.
Zhukova I. L., Orekhova S. E., Novikova L. N., Khmylko L. I.
Method of chromium-containing wastewater purification by modified wood. pp. 106--109.
Summary: The possibility of using modified sawdust for removal of chromium (III) and (VI) compounds from solutions has been established. The sorption mechanism has been suggested. Factors influencing the efficiency of purification have been determined.
Klyuev A. Yu., Prokopchuk N. R.
Colophony-terpenoid-maleic adducts: preparation, properties and use. pp. 110--118.
Summary: Methods for preparation of colophony-terphenoid-maleic adducts (CTMA) by treatment of turpentine with maleic anhydride at 190 ± 5 °C have been developed. Physico-chemical properties of CTMA have been investigated. The possibility of using CTMA in industry is discussed.
Chernaya N. V., Emello G. G., Lamotkin A. I.
Kinetics of modified tall rosin emulsion slow coagulation. pp. 119--123.
Summary: It has been found that the character and the rate of modified tall rosin electrolyte-promoted coagulation depends upon concentration of various aluminium hydroxy complexes in aluminium sulfate solution. It has been established that increasing the solution pH from 1.95 to 6.80 decreases the initial coagulation rate from 6.1 • 10-3 to 4.0 • 10-4 cm-1 • c-1 and increases slow coagulation threshold from 7.30 • 10-6 to 1.49 • 10-3 mol/l.
/ Выданні акадэміі / Навуковыя часопісы / Да пачатку старонкі
Распрацавана і падтрымліваецца Мікалаем М. Касцюковічам. Апошняе абнаўленне: 21 лістапада 2006 г.
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