Key words: supercritical conditions, сверхкритические условия, imperfect reaction systems, theory of absolute reaction rates, lattice-gas model
The review of the works devoted to modeling of the processes and physical — chemical properties is given. Specificity SCF and their role in technologies is discussed. The list of nonequilibrium and equilibrium processes in which methods of mathematical modeling have been involved is resulted. Nonequilibrium processes are grouped as the equation of chemical kinetics, hydrodynamic models and the diffusion equations,and also the description of distributions nanoparticles and phenomenological models. Equilibrium models cover an existing spectrum of treatments of experimental data from thermodynamic to the microscopic models providing the account of nonideal reactionary systems, and also with attraction of a method of molecular dynamics and energy calculations methods of quantum chemistry. The greatest attention in works is given to the equations of states for SCF and their modeling at the molecular level taking into account a presence of multicomponent mixes and specificity of interaction of components, including them asymmetry. As a whole, two areas of appendices of the equations of states concerning extensive area of thermodynamic parameters in a wide range of change of pressure and temperatures out of area of rarefied gas, and, actually, nearby-critical area are allocated. Real processes are realised out of nearby-critical area in which they are braked, in systems with the raised density of components. For modelling of processes in SCF the common approach providing self-agreement descriptions of equilibrium and kinetics of studied processes on the basis of the molecular description by means of the lattice-gas model is offered.
doi:10.34984/SCFTP.2023.18.2.002
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ГОСТ
7.0.100-2018
Modeling of Processes and Physico-Chemical Properties of Fluids in Near- and Supercritical Regions of State Parameters / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 2. – С. 9-51. - DOI: 10.34984/SCFTP.2023.18.2.002
TRANSLIT
Modelirovanie processov i fiziko-himicheskih svojstv flyuidov v okolo- i sverhkriticheskoj oblastyah parametrov sostoyaniya / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 2. – S. 9-51. - DOI: 10.34984/SCFTP.2023.18.2.002
En
Modeling of Processes and Physico- Chemical Properties of Fluids in Near- and Supercritical Regions of State Parameters. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 9-51 (2023). https://doi.org/10.34984/SCFTP.2023.18.2.002
Key words: SCF-micronization, RESS, levofloxacin hemihydrate, levofloxacin monohydrate, trifluoromethane
Micronization of levofloxacin hemihydate drug substance (LFC) by RESS using trifluoromethane (CHF3) as a polar supercritical solvent was investigated. By scanning electron microscopy, it was shown that at CHF3 temperature of 50°C, micronized LFC particles have the form of submicron-sized microbeads. At a temperature of 100°C, the particles take the form of thin (less than 0.1 microns) elongated plates with rounded edges. At this temperature, an increase in CHF3 pressure from 20 MPa to 35 MPa increases
the average particle size of these particles from 1 to 2 um, respectively. X-ray phase analysis of samples obtained at 50 °C showed the identity of the original and micronized LFC substance corresponding to the structure of levofloxacin hemihydrate — С36Н40F2N6O8⋅H2O. At the same time, it was shown that an increase in the process temperature to 100°C leads to the appearance of one of its polymorphic forms, levofloxacin monohydrate С18Н20F2N3O4⋅H2O in the micronized LFC.
doi:10.34984/SCFTP.2023.18.2.003
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ГОСТ
7.0.100-2018
Micronization of levofloxacin hemihydrate using supercritical trifluoromethane / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 19. – № 2. – С. 52-60. - DOI: 10.34984/SCFTP.2023.18.2.003
TRANSLIT
Mikronizaciya levofloksacina polugidrata s ispol'zovaniem sverhkriticheskogo triftormetana / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 19. – № 2. – S. 52-60. - DOI: 10.34984/SCFTP.2023.18.2.003
En
Micronization of levofloxacin hemihydrate using supercritical trifluoromethane. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 52-60 (2023). https://doi.org/10.34984/SCFTP.2023.18.2.003
Key words: thermodynamic modelling, Peng-Robinson and CPA (Cubic Plus Association) equation of state, acetylsalicylic acid, salbutamol sulfate, ethanol, dimethylsulfoxide
Thermodynamic modeling of pharmaceutical drugs solubility in supercritical fluids is necessary of optimization of extraction, purification, micronization and other processes. The CO2-ethanol-aspirin and CO2—dimethylsulfoxide (DMSO)—salbutamol sulfate ternary systems were used to show possibility of application of simplified models based on Peng—Robinson cubic equation of state. They were used for descri ption of phase equilibria in the CO2—ethanol binary subsystem at p=0.1—12 MPa and T = 290—345 K and in the CO2—DMSO binary subsystem at p = 0.5—18 MPa and T = 275—350 K. In the case of ternary systems, the data on the pharmaceuticals solubility in the mixed solvents were successfully approximated. Existing data at p = 7.5—35 MPa, T = 298—328 K, x(C2H5OH) = 0 and 3 mol. % were used for aspirin. Salbutamol sulfate solubility in the CO2—DMSO mixture was measures in this work at p = 8.6—21.7 MPa and T = 313—323 K by means of visual method in the thermostatic cell of constant volume. Although the obtained models describe phase equilibria, they disagree with fluid density data, especially for composition that are rich with polar components. Nevertheless, it doesn’t cause problems with usage of cubic equations of state for description of pharmaceuticals solubility in the fluid-based systems.
doi:10.34984/SCFTP.2023.18.2.004
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ГОСТ
7.0.100-2018
Some methodological aspects of solid phase–supercritical fluid equilibria modeling / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 19. – № 2. – С. 61-73. - DOI: 10.34984/SCFTP.2023.18.2.004
TRANSLIT
Nekotorye metodologicheskie aspekty modelirovaniya ravnovesij tverdaya faza— sverhkriticheskij flyuid / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 19. – № 2. – S. 61-73. - DOI: 10.34984/SCFTP.2023.18.2.004
En
Some methodological aspects of solid phase–supercritical fluid equilibria modeling. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 61-73 (2023). https://doi.org/10.34984/SCFTP.2023.18.2.004
Key words: adsorption, impregnation, supercritical fluid, N,N,NАК,NАК-tetraoctyl diglycolamide, solid phase extraction
In this study, the adsorption isotherms of N,N,N’,N’-tetraoctyl diglycolamide (TODGA) on three types of hypercrosslinked polystyrene (HCP) in supercritical CO2 were measured by gravimetric analysis. It is shown that under equal conditions (T = 313.15 K, P = 20 MPa), MN200 and MN202 HCPs adsorb up to 0.55 mmol/g and 0.59 mmol/g TODGA respectively, which allows them to be applied as the ligand carrier. The adsorption of TODGA on MN270 under the same conditions did not exceed 0.07 mmol/g. Also the temperature and medium density effect on the TODGA adsorption on MN200 was
evaluated. It is shown that isothermal decreasing of the CO2 density can increase the saturated adsorption of TODGA.
The solid phase extractant (SPE) based on MN202 and TODGA did not show extraction properties towards Nd3+, which is probably due to the matrix insufficient pore size for the formation of comparatively large complex compound. At the same time, SPE based on MN200 showed a potential feasibility of its use.
doi:10.34984/SCFTP.2023.18.2.005
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ГОСТ
7.0.100-2018
Solid phase extractants based on tetraoctyl diglycolamide and hypercrosslinked polystyrene: formation in supercritical carbon dioxide media / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 19. – № 2. – С. 74-86. - DOI: 10.34984/SCFTP.2023.18.2.005
TRANSLIT
Tverdye ekstragenty na osnove tetraoktildiglikolamida i sverhsshitogo polistirola: poluchenie v srede sverhkriticheskogo dioksida ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 19. – № 2. – S. 74-86. - DOI: 10.34984/SCFTP.2023.18.2.005
En
Solid phase extractants based on tetraoctyl diglycolamide and hypercrosslinked polystyrene: formation in supercritical carbon dioxide media. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 74-86 (2023). https://doi.org/10.34984/SCFTP.2023.18.2.005
Key words: mixed oxides, synthesis, lanthanum aluminate, lanthanum oxide, structure, water fluid, catalysts, methane oxidation
The synthesis of mixed La—Al-oxide systems with the atomic ratio La : Al 1 : 1 was studied. At the first stage, the dried mass containing La and Al nitrates and starch was burned. Heat treatment of the resulting amorphous product at a temperature of 700°C leads to the formation of LaAlO3 aluminate with a cubic perovskite structure. The composition and morphology of the product formed during subsequent processing in a water fluid (WF, density 0.2 g/cm3, 415°C) medium depends on the degree of ordering of the precursor. Crystalline LaAlO3 (cubic) in a WF medium undergoes additional ordering with a decrease in the specific surface area (Ssp.) while maintaining the crystalline structure; further calcination at 900°C does not lead to a change in the value of Ssp. and structure. When processing an amorphous precursor in a WF medium, the value of Ssp. increases and a mixture of LaAlO3 aluminates of cubic and orthorhombic structure and La and Al hydroxides is formed. Further calcination at 900°C leads to the formation of a mixture of LaAlO3 (cub.), La2O3 (hex.) and, possibly, X-ray amorphous Al2O3. The synthesized systems were studied as catalysts for methane oxidation. There was no correlation between activity and selectivity for oxidative coupling products (ethane ethylene) with the value of Ssp., but their dependence on the phase composition of the mixed La—Al-oxide was established. The systems that underwent intermediate treatment in a WF environment and contained the LaAlO3 (cub.) and La2O3 (hex.) phases turned out to be the most efficient. The results obtained indicate the high structural sensitivity of the catalytic process parameters.
doi:10.34984/SCFTP.2023.18.2.006
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ГОСТ
7.0.100-2018
Synthesis of mixed La—Al-oxides using treatment in water fluid and their catalytic properties in methane oxidation / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 19. – № 2. – С. 87-102. - DOI: 10.34984/SCFTP.2023.18.2.006
TRANSLIT
Sintez smeshannyh La—Al-oksidov s ispol'zovaniem obrabotki v srede vodnogo flyuida i ih kataliticheskie svojstva v processe okisleniya metana / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 19. – № 2. – S. 87-102. - DOI: 10.34984/SCFTP.2023.18.2.006
En
Synthesis of mixed La—Al-oxides using treatment in water fluid and their catalytic properties in methane oxidation. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 87-102 (2023). https://doi.org/10.34984/SCFTP.2023.18.2.006