Proc. of the Natl. Academy of Sciences of Belarus, Ser. Chemical Sci., 2007, No.2
/ Publications / Scientific Journals
Proc. of the Natl. Academy of Sciences of Belarus, Ser. Chemical Sci., 2007, No.2
| Proceedings of the National Academy of Sciences of Belarus
(Vestsi Natsiyanalnai Akademii Navuk Belarusi)
SERIES OF CHEMICAL SCIENCESPublished by The Belaruskaya Navuka Publishing House, Minsk, Republic of Belarus |
Number 2, 2007
CONTENTS
INORGANIC CHEMISTRY
Murashkevich A. N., Lavitskaya A. S.
Preparation and investigation of a composite based on titanium and silicon oxides. pp. 5--11
Summary: TiO2--Si2 composites as hybrid xerogels and precipitated powders have been obtained by sol-gel and coprecipitation methods. Titanium and silicon alkoxides and TiCl3 have been used as starting materials. Properties of Ti2 -- Si2 composites have been characterized with XRD (X-ray diffraction), IR-spectroscopy, thermogravimetry and adsorption gravimetry. Change of structural-sorption properties of the composite with heating has been studied. It has been shown that thermal transformations are accompanied by specific surface reduction caused by Ti2 crystallization.
Mozheiko F. E, Korshuk E. E, Potkina T. N.
Intensifying processes of phosphorite suspensions' dehydration. pp. 12--17
Summary: It has been shown that to achieve high efficiency for processes of dehydration, thickening and filtration of the pulp formed during flotation enrichment of phosphorite ores, the latter should be treated first with coagulants (inorganic salts of di- or trivalent metals), and then with polymeric flocculants such as polyacrylamide.
COLLOID CHEMISTRY
Komarov V. S., Leonenko L. I., Rat'ko A. I.
Preparation of carbon-mineral adsorbents from montmorillonite and organic compounds. pp. 18--22
Summary: Conditions for modification of the structure of a clay mineral (montmorillonite) by organic substances' solutions have been studied. The concentration of polymer in the solution providing maximum uptake capacity of the carbon-mineral sorbents obtained has been determined.
It has been shown that montmorillonite saturation in 1--2% solutions ensured maximum sorption capacity of the samples obtained. This phenomenon has been explained using the theory of polymeric solutions. The mechanism for sample structure formation depending upon montmorillonite saturation degree by an organic compound, has been discussed.
Komarov V. S., Leonenko L. I., Rat'ko A. I.
Carbon-mineral adsorbents based on polymer-modified montmorillonite. pp. 23--26
Summary: Conditions for modification of the structure of a clay mineral (montmorillonite) by water solutions of polymers have been studied. The concentration of polymer in the solution keeping maximum uptake capacity of the carbon-mineral sorbents obtained has been determined. The mechanism of structure formation of samples has been discussed. This phenomenon has been explained according to basic theoretical principles of colloidal chemistry.
Rat'ko A. I., Kouznetsova T. E, Romanenkov V. E., Eremenko S. I., Tikhov S. E, Khabibulin D. E, Lapina O. B., Sadykov V. A.
Specific features for reaction of aluminum powder with water in presence of surfactants. pp. 27--31
Summary: It has been found that the reaction of aluminum hydrothermal oxidation with water in presence of surfactants has two definite areas, namely: kinetic, when oxidation rates in solutions are higher than in water, and diffusive when conversion degree for aluminium in water is higher than in solutions. It has been found that the effect of various surfactants consists in making products amorphous, reducing specific surface area, widening alumina pores, and in conversion of the hysteresis loop for carbon tetrachloride vapour sorption-desorption isotherms, that provides the evidence for alumina mesopore shape change.
Opanasenko O. N., Zhigalova O. L., Ovseenko L. V., Dikhievskaya L. V.
Regulation of alkylamidoimidazoline-based surfactants' emulsifying ability. pp. 32--38
Summary: The effect of oleophilic liquids' solubilization on surfactant adsorption processes at water-air and oil-water phase borders has been studied. It has been shown that solubilization of non-polar hydrocarbons with micellar solution of alkylamidoimidazoline-based surfactants results in critical micelle concentration increase and equilibrium shift in micellar system towards increased content of single surfactant molecules, that favors emulsification at the oil-water phase border. It has been shown that solubilization of a non-polar hydrocarbon allows preparing bitumen emulsions with optimal colloidal chemistry characteristics.
ANALYTICAL CHEMISTRY
Zayats M. E, Leshchev S. M., Yurchenko R. A., Petrashkevich N. V.
Development of improved extraction method of wine and grape juice sample preparation for gas chromatography determination of hydrophobic pesticides. pp. 39--44
Summary: On the basis of literature data on cypermethrin, lambda-cyhalotrin, tolylfluanid and chlorothalonil solubilities in n-hexane and water, the possibility of hexane use for the extraction sample preparation from wines and grape juices for gas chromatography determination of these pesticides has been established. Estimated values of distribution constants for studied substances ranged from several thousands to 108, the recovery is close to 100%. Hexane is currently used from time to time as an extractant for determination of these pesticides. However, its application is limited by foam formation causing the necessity of extra steps in the multistep sample preparation process. It has been established that ammonium sulfate addition, in amounts about 5 g per 10 ml of wine, almost completely suppresses foam formation during hexane extraction of the above pesticides. This allows preparation of the sample in 5--10 minutes instead of traditional 1--2 days, noticeably reduces the amount of reagents spent, increases the analysis accuracy and minimizes the background noise level on chromatograms. The method of sample preparation of wines and grape juices for cypermethrin, lambda-cyhalotrin, tolylfiuanid and chlorothalonil quantitative determination below the maximum allowed level has been proposed.
PHYSICAL CHEMISTRY
Yegiazarov Yu. G., Soldatov V. S., Potapova L. L., Radkevich V. Z., Khaminets S. G.
Platinum-modified carbon fiber sulfonic cation exchangers as electrodes for hydrogen-air fuel cell. pp. 45--51
Summary: Method for preparation of anode and cathode materials based on a carbon fiber cation exchanger, with both proton and electron conductivity, has been developed. Electrocatalytic activity of prepared electrodes in operation mode of hydrogen-air fuel cell has been determined. Activities of the best samples are comparable with the ones of analogues from foreign manufacturers.
Azarko V. A., Agabekov V. E., Strigutsky V. P., Mikhailovsky Yu. K., Kalechits G. V., Shulitsky B. G.
Paramagnetic properties of thermovacuum-formed films of 1H-indole-3-(N-phenyl)aldonitrone. pp. 52--55
Summary: Kinetics and mechanism of UV-promoted transformation of 1H-indole-3-(N-phenyl)aldonitrone in thin film state have been studied by ESR-spectroscopy. It has been found that ESR signal influenced by an appropriate geometric configuration in particular intermolecular interaction of the charge-transfer type can be present in the spectra.
Rabchynski S. M., Lisiankou A. D., Streltsov E. A.
Electrochemical preparation of photosensitive CdTe films on Ti substrates. pp. 56--61
Summary: A method for the electrodeposition of photosensitive semiconducting n-CdTe films (with thickness up to 2 µm) onto Ti surface covered with chemically deposited sublayer of CdS (200 nm) has been developed. The cadmium sulfide sublayer provides the substantial adhesion of the CdTe film to the substrate and determines the micro structure of its poly crystalline deposit. The photoelectrochemical behavior of Ti/CdS/CdTe electrode is described by the model of isotype n-n-heterojunction in which the space division of photoelectrons and photoholes occurs both on CdTe/electrolyte and CdS/CdTe interface. It has been shown that the CdS sublayer hinders the dark oxidation of the telluride.
ORGANIC CHEMISTRY
Dikusar E. A., Kozlov N. G, Potkin V. I., Yuvchenko A. P., Tlegenov R. T.
Synthesis of 11-(2-chlorobenzoiloxy)lu-pinine and its salts with a series of carboxylic, organic sulphonic and arsenic-containing acids. pp. 62--64
Summary: A method of preparation for salts of ll-(2-chlorobenzoiloxy)lupinine with a series of carboxylic, organic sulphonic and arsenic-containing acids has been described.
BIOORGANIC CHEMISTRY
Potapovich M. V., Tarun E. I., Eryomin A. N., Isakova V. G, Khlebnikova T. S., Lakhvich F. A.
Effect of fluorinated cyclic b,b'-triketones on catalytic activity of urease and glucose oxidase - peroxydase pair. pp. 65--73
Summary: Fluorinated cyclic b,b'-triketones inhibited the soybean urease in aqueous medium: 2-(3-fluorobenzoyl)-5,5-dimethyl-cyclohexane-1,3-dione and 2-(4-fluorobenzoyl)-5,5-dimethylcyclohexane-1,3-dione had the inhibition constant of 14.9 µM. These compounds inhibited urease activity 1,3 and 8,7 times, respectively, more efficiently than the known herbicide tralkoxydime and 2-benzoyl-5,5-dimethylcyclohexane-1,3-dione. Effect of fluorinated b,b'-triketones on the catalytic activity of the glucose oxidase - peroxydase pair was less pronounced, and sometimes activation occurred instead of inhibition.
POLYMER CHEMISTRY
Bil'dyukevich A. V., Semenkevich N. G., Pratsenko S. A.
Effect of polyethersulfone molecular weigth upon membrane transport characteristics. pp. 74--79
Summary: The effect of polyethersulfone (PES) molecular weigth upon the structure and permeability of the ultrafiltration membrane has been studied. It has been established that for membranes obtained from "polymer-solvent" and "polymer-solvent-nonsolvent", hydraulic permeability increases and selectivity goes through an extreme peak with decreasing of the molecular weight of PES.
GEOCHEMISTRY
Kudelsky A. V.
Some peculiarities of oils, brine- and oil-dissolved gas geochemistry within Pripyat' oil and gas basin. pp. 80--89
Summary: Some geochemical peculiarities of oil, brine-and oil-dissolved gas characterized by rather high chocentrations of hydrogen sulfide, ammonia (ammonium salts) and presence of cyanides in the sequence of some areas, have been described for the first time. The presence of cyanides is a unique property of oil and brines from the Pripyat' Trough, caused by geochemical effects of repeated high-temperature metamorphism of oils accompanied by a paragenetic release of H2S, NH3 (NH4+) and HCN.
TECHNICAL CHEMISTRY AND CHEMICAL TECHNOLOGY
Basalyha L L, Vorob'eva E. V., Krutko N. P., Domovskaya T. G, Bychek P. S., Kirienko V. M., Cherkas O. A., Nikolaeva N. M.
Analysis of clay and mineral admixtures in products of potash ore processing by IR spectroscopy. pp. 90--94
Summary: The possibility of qualitative and quantitative analysis of clay and mineral admixtures in products of potash ore processing by IR spectroscopy has been demonstrated for the first time. Some of the parameters that determine the adequacy of technique and results reproducibility have been studied.
Lipik V. T., Prokoptchuk N. R.
Alkaline hydrolysis of polyethyleneterephthalate waste. pp. 95--100
Summary: The results of fused PET depolymerization with alkalis have been described. The possibility of terephtalic acid and ethylene glycol preparation, by reacting the melted polymer with alkalis, has been shown. It has been established that the best reagent for depolymerization is calcium hydroxide. The developed method of chemical recycling does not require high temperatures and pressure, and allows obtaining monomers suitable for synthesis of new products, within short time.
Dyakonov O. M.
Formation of protective pyrocarbonic films on metal particle surfaces. pp. 101--105
Summary: The structure of pyrocarbon films obtained on metal particles' surface (bearings of ShH15 steel) by low-temperature (600--1000°C) pyrolysis of oil phase and its gaseous destruction products have been investigated. It has been found that film formation occurs through precipitation of dense nonporous chark-like residue followed by transformation into carbonaceous pyrocarbon with anthracite structure at higher temperatures. Metal chip shifts the temperature of these processes to lower (below 200°C) area due to its catalytic properties.
Dormeshkin O. B.
Effect of ammonium ions on neutralization process in the system CaO--H3PO4--H2SiF6--H2O. pp. 106--111
Summary: The effect of ammonium ions on neutralization process in the system CaO--H3PO4--H2SiF6--H2O has been studied. It has been established that in presence of ammonium ions the minimum of fluoride ion solubility is shifted to higher pH values. The effect of basic technological parameters on purification degree, as well as on chemical and technological properties of deposits formed during purification, has been investigated, and optimal conditions for phosphoric fertilizer production waste water purification in presence of ammonium ions have been determined.
Levitsky I. A., Bohdan K. O.
Ceramic masses for manufacturing products of front ceramics. pp. 112--116
Summary: Results of research and development of ceramic masses for manufacturing front ceramics based on fire-resistant, refractory and fusible clay raw materials and lean additives have been presented. Physical and chemical properties, color characteristics, structure and phase composition of the materials obtained have been investigated; the technology for making front ceramics products has been developed.
Bambalov N. N., Samokar O. M., Navosha Yu. Yu., Zhdanok S. L.
Humic acid photolysis by UV radiation. pp. 117--120
Summary: Irradiation of peat and sapropel humic acid solutions in 0.1N NaOH by UV and visible light results in optical density decrease, because of destruction processes followed by partial mineralization into final degradation products such as carbon dioxide, water etc. The UV part of the spectrum makes the main contribution to photo destruction of humic acids, its share being more than 80% of the total optical density decrease, while the visible light contribution to destruction processes does not exceed 20%.
SCIENTISTS OF BELARUS
Lesnikovich A.I., Krutko N.P., Agabelov V.E. et al.
Vladimir Sergeevich Soldatov (On the occasion of 70th birthday). pp. 121--123
Click here to read this article in Russian (Win1251)
/ Publications / Scientific Journals / Back to Top of Page
Designed and maintained by Dr. Nikolai N. Kostyukovich. Last updated: May 14, 2007
Created with assistance of Dr. Ignatii I. Korsak
Copyright © 2007 The National Academy of Sciences of Belarus
Copyright © 2007 The Belaruskaya Navuka Publishing House
