Key words: solubility, IR-spectroscopy, supercritical fluids
A self-consistent approach to the measurement of solubility of biologically active compounds in supercritical (SC) media based on the infrared spectroscopy is exemplified by paracetamol in supercritical CO2. According to this approach, the integrated extinction coefficient for a chosen analytical spectral band is determined from additional spectroscopic measurement of the compound under study dissolved in an inert solvent at known concentrations in the considered range of the parameters of state (pressure and temperature — p, T ). The values of solubility of the compound under study in the SC medium are calculated based on the above obtained values of the extinction coefficient and the analytical values of the integral intensity of the chosen spectral band for saturated solutions in the p,T-range of interest. The method allows one to determine the solubility with a high accuracy even if the measured values are as low as 10-4—10-1 mol.%.
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ГОСТ
7.0.100-2018
A New Method for Measuring the Solubility of Slightly Soluble Substances in Supercritical Carbon Dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 4-15. - DOI:
TRANSLIT
Novyj metod izmereniya rastvorimosti slaborastvorimyh veshchestv v sverhkriticheskom diokside ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 4-15. - DOI:
En
A New Method for Measuring the Solubility of Slightly Soluble Substances in Supercritical Carbon Dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 4-15 (2015). https://doi.org/
Key words: subcritical water, cellulose, polyols, hydrolytic hydrogenation, hypercrosslinked polystyrene, heterogeneous catalysis
It is demonstrated that subcritical water is efficient as a medium for the cellulose conversion process to produce polyols. A novel type of Ru-containing catalysts supported on hypercrosslinked polystyrene (HPS) is suggested. In the presence of the catalyst containing 1% Ru the total yield of sorbitol and mannitol reaches 50 %; this is comparable with the results obtained in the presence of more complex and, therefore, more expensive catalytic systems. The influence of both the process conditions and the catalyst properties on the target product yield is studied. The hydrolytic hydrogenation of cellulose in subcritical water using Ru-containing catalysts can be considered as a basis for novel technologies of cellulose-containing biomass conversion and production of raw materials for chemical synthesis and industrial production of second generation biofuels.
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ГОСТ
7.0.100-2018
Cellulose Convertion to Polyols in Subcritical Water / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 16-25. - DOI:
TRANSLIT
Konversiya cellyulozy v mnogoatomnye spirty v subkriticheskoj vode / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 16-25. - DOI:
En
Cellulose Convertion to Polyols in Subcritical Water. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 16-25 (2015). https://doi.org/
Key words: polymer microparticles, encapsulation of bioactive components, sustained release dosage forms, supercritical carbon dioxide
The process of supercritical fluid encapsulation of pharmaceutical grade risperidon into bioresorbable D,L-polylactide microparticles by PGSS (Particles from Gas Saturated Solutions) method is studied. Micronization and change of morphology of risperidon crystals during its encapsulation into polymer plasticized by supercritical carbon dioxide is experimentally observed. This finding enabled fabrication of polymer structures of various dispersion (10—100 μm) and morphologies comprising up to 40 wt.% of risperidon without any use of organic solvent. The kinetics of risperidon release from the polymer microparticles into physiological solution is studied by UV-spectrophotometry. It is shown that the use of different molecular weight D,L-polylactides enables one to extend the risperidon release time from bioresorbable polymer particles fabricated by PGSS up to 10 days in a controllable manner.
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ГОСТ
7.0.100-2018
Supercritical Fluid Fabrication of the Components for Risperidon Sustained Release Injectable Formulation / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 26-38. - DOI:
TRANSLIT
Sverhkriticheskoe flyuidnoe formirovanie komponentov in"ekcionnoj formy risperidona prolongirovannogo dejstviya / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 26-38. - DOI:
En
Supercritical Fluid Fabrication of the Components for Risperidon Sustained Release Injectable Formulation. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 26-38 (2015). https://doi.org/
Transformation of Alkylbenzenes in Oxidizing Medium on ZSM-5 Catalyst under Supercritical Conditions
Key words: alkylbenzenes, partial oxidation, H-ZSM-5
Reactions of substituted benzenes — toluene, p-xylene, fluorobenzene, phenol, cumene and styrene — with nitrous oxide as an oxidant on H-ZSM-5 catalyst under supercritical conditions at 345—420°C and 70—150 atm was investigated.
It is shown that the products of disproportionation, isomerization and condensation that do not contain oxygen form predominantly. Only in the oxidation of toluene the selectivity to oxidation product (cresols) reaches up to 35 %. The yield of corresponding phenols in oxidation of alkyl-, hydroxy- and fluorobenzenes is negligible. Double bond conjugated with π-system of benzene rings (styrene), as well as the presence of branched alkyl substituents (in cumene) and hydroxyl-group (in phenol) hinder the formation of benzene ring oxidation products.
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ГОСТ
7.0.100-2018
Transformation of Alkylbenzenes in Oxidizing Medium on ZSM-5 Catalyst under Supercritical Conditions / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 39-48. - DOI:
TRANSLIT
Prevrashchenie alkilbenzolov v okislitel'noj srede na katalizatore ZSM-5 v sverhkriticheskih usloviyah / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 39-48. - DOI:
En
Transformation of Alkylbenzenes in Oxidizing Medium on ZSM-5 Catalyst under Supercritical Conditions. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 39-48 (2015). https://doi.org/
Key words: ibuprofen, supercritical CO2, polymorphism, quantum chemistry, molecular dynamics simulation
The conformational equilibria of ibuprofen in vacuum and in supercritical carbon dioxide are studied using methods of quantum chemistry and classical molecular dynamics. In supercritical carbon dioxide ibuprofen forms 12 different conformations, two of them correspond to the structures of the molecule in the crystal lattice of the first and second polymorph. It is shown that the GAFF force field allows one to obtain the characteristics of conformers, almost coinciding with those obtained by quantum-chemical calculations in the B3LYP/cc-pVTZ level of theory.
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ГОСТ
7.0.100-2018
Conformational Lability of Ibuprofen in Supercritical Carbon Dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 49-62. - DOI:
TRANSLIT
Konformacionnaya labil'nost' ibuprofena v sverhkriticheskom diokside ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 49-62. - DOI:
En
Conformational Lability of Ibuprofen in Supercritical Carbon Dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 49-62 (2015). https://doi.org/
Key words: molecular association, solubility, supercritical fluid, methylxanthine
Experimental data on solubility of methylxanthines (theophylline and theobromine) in the system «supercritical (SC) CO2-methanol» at various concentrations of methanol is analyzed in the framework of the ASL (Associated Solution + Lattice) model based on the molecular association theory and the simple lattice concept. 1H NMR spectroscopy is applied to investigate hetero-association of methylxanthines with methanol at 313 K. The contribution of molecular association to the solubility of methylxanthines in a mixed SC CO2-methanol solvent is discussed. It is shown that the presence of NH groups in methylxanthine molecule (i.e. theobromine and theophylline vs. caffeine) leads to the increasing contribution of solubility component related to the molecular association.
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ГОСТ
7.0.100-2018
Effect of Molecular Association on Methylxanthine Solubility in Supercritical Solvent CO<sub>2</sub>-Methanol / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 63-70. - DOI:
TRANSLIT
Vliyanie molekulyarnoj associacii na rastvorimost' metilksantinov v sverhkriticheskom rastvoritele CO2-metanol / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 63-70. - DOI:
En
Effect of Molecular Association on Methylxanthine Solubility in Supercritical Solvent CO<sub>2</sub>-Methanol. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 63-70 (2015). https://doi.org/
Key words: regeneration, supercritical fluid, catalyst of medium temperature isomerization, isomerization, pentane fraction, isoalkane
Regeneration of medium-temperature isomerization catalyst in supercritical carbon dioxide added with co-solvent is studied. The effect of regeneration conditions upon the catalytic activity is discussed.
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ГОСТ
7.0.100-2018
Regeneration of the Catalyst for Medium Temperature Isomerization in Supercritical Carbon Dioxide Modified with Isoalkanes C<sub>5</sub>—C<sub>6</sub> / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 71-83. - DOI:
TRANSLIT
Regeneration of the Catalyst for Medium Temperature Isomerization in Supercritical Carbon Dioxide Modified with Isoalkanes C5—C6 / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 71-83. - DOI:
En
Regeneration of the Catalyst for Medium Temperature Isomerization in Supercritical Carbon Dioxide Modified with Isoalkanes C<sub>5</sub>—C<sub>6</sub>. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 71-83 (2015). https://doi.org/
Key words: crosslinked polymeric networks, crosslinking agents, supercritical carbon dioxide, rhodium acetylacetonate, impregnation, rhodium nanosized particles
Three types of polymers — phenol-formaldehyde copolymer, polypropyleneimine and polyamidoamine dendrimeres — are synthesized using polycondensation method. Mesoporous polymeric networks are formed by treating two last polymers with crosslinking agents. For the first time an impregnation of polymeric networks with rhodium acetylacetonate in supercritical carbon dioxide is carried out and optimal conditions are determined. Using Raman spectroscopy it is shown that metal content in polymer networks is within the range of 0,3—2,0% mass. depending on the type of polymer and crosslinking agent and on the crosslinking degree. By reduction of immobilized rhodium acetylacetonate with molecular hydrogen polymer samples including rhodium nanoparticles are obtained. According to preliminary data, these samples possess extremely high activity as catalysts for hydrogenation of unsaturated compounds.
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ГОСТ
7.0.100-2018
Synthesis of Nowel Promising Materials via Impregnation of Crosslinked Polymeric Networks with Metal Complexes in Supercritical Carbon Dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 84-88. - DOI:
TRANSLIT
Poluchenie novyh perspektivnyh materialov putem impregnacii sshityh polimernyh setok metallokompleksami v srede sverhkriticheskogo dioksida ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 84-88. - DOI:
En
Synthesis of Nowel Promising Materials via Impregnation of Crosslinked Polymeric Networks with Metal Complexes in Supercritical Carbon Dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 84-88 (2015). https://doi.org/
Key words: acetylene hydrogenation, palladium catalyst regeneration, supercritical CO2, modifier
The results of the regeneration of a deactivated palladium catalyst of acetylene hydrogenation using the supercritical fluid extraction process at T = 130 °C, P = 250 bar are shown. The activity of the catalyst regenerated in supercritical carbon dioxide modified with acetone comparable with activity of the catalyst regenerated by the conventional method.
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ГОСТ
7.0.100-2018
The Regeneration of Palladium Catalyst of Acetylene Hydrogenation in Modyfied Supercritical CO<sub>2</sub> / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2015. – Т. 10. – № 3. – С. 89-96. - DOI:
TRANSLIT
Regeneraciya palladievogo katalizatora gidrirovaniya acetilena v srede modificirovannogo sverhkriticheskogo SO2 / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2015. – Т. 10. – № 3. – S. 89-96. - DOI:
En
The Regeneration of Palladium Catalyst of Acetylene Hydrogenation in Modyfied Supercritical CO<sub>2</sub>. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 89-96 (2015). https://doi.org/