Fine Chemical Technologies

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Vol 11, No 6 (2016)
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15-27 196
A review of scientific publications that describe systems with a three-phase splitting region is presented. Mechanisms of a three-phase splitting region formation are shown. All the suggested classifications of diagrams with a three-phase splitting region are presented. Methods for studying the evolution of a three-phase splitting region are described. Problems connected with the mathematical modeling of liquid - liquid - liquid equilibrium are considered. The ability of mixtures to form three-phase splitting regions and opportunities of separating such mixtures by special methods is analyzed. A list of known systems with three and more liquid phases is presented.
28-35 187
Influence of additives of synthetic polymers of various natures on reactionary ability of the nanostructured iron catalysts in the three-component Fe-paraffin-polymer system in Fischer-Tropsch (FTS) in the slurry reactor was studied. The polymers used: polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polystyrene, cross-linked with divinylbenzene (PS-DVB), polyamide-6 (PA). The catalysts obtained by droplet thermolysis is influenced by, the nature of the stabilizing polymer. Besides the conversion of the synthesis gas depends on the contact time and is between 10 to 80%. The highest rate of FTS is observed in the Fe-paraffin-PAN. The conditions of synthesis in Fe-paraffin-polymer systems produced a wide range of saturated and unsaturated compounds. It is found that the nature of the stabilizing polymer also affects the olefin /paraffin ratio. Based on experimental data the analysis of kinetic models for the flow of CO is carried out, a kinetic and thermodynamic characteristics of the process was obtained. The relationship between the values of the activation energies and the nature of the stabilizer was established.
36-42 174
Epichlorohydrin is an important product of the basic organic synthesis. One promising direction of epichlorohydrin manufacturing is the liquid-phase epoxidation of allyl chloride with an aqueous solution of hydrogen peroxide in an organic solvent, methanol, in the presence of a heterogeneous catalyst, a titanium-containing zeolite. The multicomponent system of epichlorohydrin production according to this method contains allyl chloride, methanol, water, epichlorohydrin, 3-chloro-1,2-propanediol, 3-chloro-1-methoxypropanol-2 and hydrogen peroxide. In this work the thermodynamic topological analysis of the phase diagram of this multicomponent system of epichlorohydrin production was performed. On the basis of this study a principal technological scheme of separation of the studied system containing five distillation columns and a Florentine vessel was proposed.
43-54 148
The processes of granulation by crystallization of molten droplets in the flow of a cooling agent (prilling) and on the cooled surfaces of the granulators are widely used in the chemical and allied industries. The process of granulation (crystallization) of melts and qualitative indicators of granular products, their marketability is determined by the transfer phenomena in the phases and by the kinetics of crystallization and enantiotropic polymorphic transformations in the crystalline phase. Quantitatively the latter are given in the form of dependences of the rate of nucleation and growth of centers of transformation. The processes kinetics is usually less studied, but it determines the structure of the formed crystal phase and the maximum rate of the process. Therefore, most attention is focused on its study. The description of the scheme, of developed experimental laboratory facilities for the study of the rates of nucleation and growth of crystallization centers in the polycrystalline front of the growing group of crystals, as is the case when crystallization occurs in devices in real conditions (constrained growth of crystals) and single crystals in a thin layer (unrestricted growth of crystals) is given. The transfer of heat in the measuring cell and the sample and possible errors of experimental results were estimated using the natural scale method.


55-62 273
Carnosine is a natural dipeptide antioxidant. It is proved that it protects human’s cells from oxidative stress. However, it has a short lifetime in a human organism due to the carnosinase activity. In order to solve this problem we used carnosine encapsulated in liposomes. Thus, the aim of this study was the creation of a new liposomal carnosine drug form. We used two encapsulation methods that show different carnosine behavior: a passive and an active one. We took into account that conditions of obtaining liposomes such as lipid composition, pH and temperature are important. In this study the lipid composition providing the maximum encapsulation efficiency was determined. Dipalmitoylphosphotidylcholine (DPPC) and its mixture with cholesterol (Chol) wereused as composition lipids. It was shown that the active encapsulation method using the creation of ammonium sulphate pH gradient provided the best results: 41.7% encapsulation efficiency (according to NMR spectroscopy) when using DPPC:Chol (7:3) mixture as lipids. Moreover, the properties of the liposomes were studied. Using the dynamic light scattering and electron microscopy methods carnosine liposomes (DPPC:Chol) were shown to be spherical nanoparticles with an average size of 133 nm. Carnosine release kinetics studied with the use of a France’s cell showed that carnosine was released in 24 hours (liposomal composition DPPC:Chol was 7:3). A study of carnosinase action on liposomal carnosine showed that the maximum amount of carnosine remained unchanged in DPPC:Chol liposomes (7:3). The results of the study make it possible to conclude that liposomal carnosine has a better activity in the human organism.
63-67 204
The work is dedicated to the production of polymer suspensions using ultrasonic dispergation in a flow mode. An apparatus was designed on the basis of a Russian flow ultrasonicator. The applicability of this apparatus for obtaining aqueous dispersions of polymeric micro- and nanoparticles by means of one-step emulsification followed by solvent extraction / evaporation was demonstrated. The influence of the process parameters on the characteristics of the obtained suspensions was studied. The particle size distribution and the average size of the resulting particles were evaluated by using Delsa Nano S, Beckman Coulter laser analyzer (USA). The dependence of the average diameter of the suspension particles on the stabilizer concentration and on the change of the phases feed rate was shown. When polyvinyl alcohol was used as a stabilizer in the concentration range 0.5-2%, the average particle size was 30-400 nm. The feed rates of the aqueous and organic phases affect the nature of the particle size distribution.
68-74 184
The changes of the 8-oxo-2'-deoxyguanosine (8-oxo-dG)/dG ratio in the DNA of laboratory mice hepatocytes under the influence of toxic stress were studied. It was shown that the injection of carbon tetrachloride causes the growth of 8-oxo-dG level. A rapid increase in the level of 8-oxo-dG in DNA occurs during the first day of the experiment at short-term toxic stress. Subsequently, 48 hours after the initial injection, the level of 8-oxo-dG decreases to the control values. This change in the value of the biomarker can be attributed to the activation of the reparative and antioxidant systems. The subsequent injection results again in an increase of 8-oxo-dG level, and the latter only increases thereafter. This reflects the exhaustion of the reparative potential of the organism and accompanies the progress of inflammation and pathological change of the liver tissue.
75-82 154
Metalloorganic complexes of rare earth elements with porphyrins have attracted attention over the past years in view of potential applications as templates for biology, nanotechnology and medicine. For deeper understanding and studying of their properties the knowledge of electronic structure and bonding in these compounds is required and should be investigated essentially by a photoelectron spectroscopy. In present work the electronic structure and stability of tetrakis-porphyrins and its ytterbium complexes were studied experimentally by X-ray (XPS) photoemission spectroscopy. The X-ray photoemission data show the different atomic constituents in accordance with its states in molecules which can be related to the peaks of N1s, C1s, O1s, Yb4d appearing in the electronic spectra. In the tetraphenylporphyrin free base spectrum of the N1s state core levels there are two peaks of N1s which were assigned to sp3 and sp2 nitrogen respectively (pyrrol- and azastates). In Yb metalloporphyrin charge distribution is more uniform for N1s spectra and thus wide single peak of N1s states reflects small difference between pyrol- and aza-nitrogen. The analysis of Yb4d electronic states shows that spectra do not consist of the spin-orbit split doublet, but instead is composed of asymmetric peak with multiplet splitting. Divalent Yb has a filled 4f shell, i.e. a 4f14 configuration, and the 4d spectra shows the doublet with 3:2 ratio, while for trivalent Yb, 4f13, the 4d peaks consist of a multiplet. The spectrum analysis demonstrated the multiplet splitting of Yb 4d and trivalent state in Yb(acac)-5,10,15,20-tetrakis-porphyrins. The research of thermal stability of tetraphenylporphyrin, octabrominetetraphenylporphyrin, ytterbium acetylacetonate octabrominetetraphenylporphyrin by X-ray photoelectron spectroscopy and thermogravimetry measurements in the range of temperatures of 30-450°C (when heating in ultrahigh vacuum) has shown destruction of the octabrominetetraphenylporphyrin and ytterbium acetylacetonate octabrominetetraphenylporphyrin after warming up higher than 150ºС while free base porphyrines (tetraphenylporphyrines) have shown thermal stability under vacuum conditions.


83-90 163
«New atomic energy technologies» federal program is being realized in Russia. This program includes experimental energy complex development and building, which contains: - a natural safety lead coolant fast reactor «BREST-300»; - a spent fuel recycle facility including fuel fabrication and re-fabrication, radioactive waste immobilization and discarding in accordance with radioactively-equivalent state. The current recycle facility preliminary design involves dry operation of spent fuel elements disassembly using steel shell dissolution by liquid zinc. Fuel element shells are made of special radiation-proof steel «EP-823» containing the following amounts of elements (%): C - 0.2; Мn - 0.8; Si - 1; S - 0.01; Р - 0.015; Сr - 12; Ni - 0.5; Мо - 0.9; V - 0.2; N - 0.05; Fe - 84.325. After dissolution zinc liquid containing steel elements is distilled. Still zinc is sent back to shells dissolution. The bottom product is destructurized particulate with the composition corresponding to original steel. Actinides steel shell and bottom product contamination was predicted using computer modeling. In accordance with the project technical specification actinide content in the disposable materials must be under 0.0001%. Thus, the bottoms product should be purified. Oxidative slag cold crucible induction melting purification was chosen and tested in laboratory scale. The following slag types were investigated: Al2O3-SiO2, B2O3-SiO2, Al2O3 - CaO. It was found that the most appropriate slag is B2O3-SiO2, and the optimal process temperature is about 1600°C.
91-97 203
The article considers specific features of the formation of nanocomposites based on the lattice packing of SiO2 nanospheres (opal matrices) with clusters of titanium and iron compounds (FeTiO3, FeTi2O5, TiO2, Fe2O3) embedded into nanopores between spheres. For the formation of the nanocomposites samples of opal matrices with the sizes of single-domain regions > 0.1 mm3 were used. The diameter of the SiO2 nanospheres was ~260 nm. Nanocomposites with the volume > 1 cm3 and 10-15% of interspherical nanospacing filled by crystallites of titanium and iron compounds were obtained. The composition and structure of the nanocomposites were studied by electron microscopy, X-ray diffraction and Raman spectroscopy. The dependence of the composition of the synthesized materials on the conditions of their preparation is shown. Results of measurements of the frequency dependences (within the range 1 MHz - 3 GHz) of the magnetic and dielectric characteristics of the obtained nanostructures are presented. Hysteresis loops were studied for the obtained samples.


98-102 154
Methods of introducing a water-soluble biocide modifier, oligohexamethyleneguanidine hydrochloride, into epoxy-amine systems were studied. The obvious way is the introduction of the modifier in the waterborne epoxy-amine systems. However, this leads to cured systems with reduced mechanical properties. Introduction of oligohexamethyleneguanidine hydrochloride solutions in organic solvents into epoxy-amine systems allows obtaining a homogeneous system, but their application is limited by the presence of a volatile solvent. Finally, introduction of oligohexamethyleneguanidine hydrochloride solutions in a water-soluble amine curing agent into epoxy-amine systems has good prospects. It is shown that the analyzed modifier has good solubility in ethylenediamine, but poor solubility in oligooxypropylenediamine. It was found that the modifier is capable of interacting chemically with epoxy resins at 22°C to form an elastic insoluble material. In an epoxy-amine system with a more active hardener (ethylenediamine) oligohexamethyleneguanidine hydrochloride acts as a plastifier (flexibilizer). This significantly reduces the glass transition temperature of the matrix (from 53 to 37ºC).
103-107 163
It is known that for decrease in viscosity polymeric binding on the basis of epoxy oligomers in their composition injecting solvents of the different nature and thermodynamic compatibility. In this paper the dependences describing influence on shrinkage, kinetics of increase and maximum level of strains from diluents content and temperature of curing of epoxy oligomers are established. Introduction about 20 % of the active diluents (DEG-1 and SO-3) in system on the basis of epoxy oligomers leads to decrease in viscosity in ~3 times, to improvement of imbibition quality of fibrous fillers, increase of volume contraction (on ~2.5. %) and decrease in residual stresses in ~6 times as a result of increase of mobility of pieces of a polymeric chain in a three-dimensional grid, and also to decrease in glass transition temperature no more than ~20°C.
108-112 180
The article is devoted to some pages in the history of the library of one of Russia’s oldest higher education institutions, M.V. Lomonosov Moscow Institute of Fine Chemical Technology (MITHT): the organization of the library at the Moscow High Women Courses (1901-1918), the main library of the 2nd MSU (1918-1930), the MITHT scientific and technical library (1930-2015). The today’s library of the MITHT campus of the Moscow Technological University is described. The contribution of outstanding scientists that taught at different times in MITHT to the creation of the specialized university type library is noted. The surnames of the MITHT library managers starting with the Soviet period are given. Some information is published for the first time.

ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)