Key words: local molecular dynamics, FTIR spectroscopy, glassy polymers, relaxation transition, method of conformational probes, supercritical carbon dioxide
To study the local molecular mobility of polysulphone and polycarbonate processed in supercritical carbon dioxide the FTIR-spectroscopic method of conformational probes is applied. The temperatures and nature of secondary relaxation transitions are determined. The effect of supercritical fluid processing on relaxation transitions in polymers and on the difference in conformation enthalpies of probe molecules is analyzed.
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ГОСТ
7.0.100-2018
Effect of supercritical carbon dioxide on secondary relaxation transitions in polysulphone and polycarbonate: method of conformational probes / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 4-10. - DOI:
TRANSLIT
Vliyanie sverhkriticheskogo dioksida ugleroda na vtorichnye relaksacionnye perekhody v polisul'fone i polikarbonate: metod konformacionnyh zondov / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 4-10. - DOI:
En
Effect of supercritical carbon dioxide on secondary relaxation transitions in polysulphone and polycarbonate: method of conformational probes. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 4-10 (2013). https://doi.org/
Key words: critical parameters, supercritical mixtures, concentration, equation of state, compressibility factor, reduced parameters, relative error
The p, ρ, T, x-relationshi ps for water + aliphatic alcohol (methanol, ethanol, n-propanol) mixtures in near-critical and supercritical conditions obtained by compressibility measurements using the piezometric setup are analyzed. It is demonstrated that thermodynamic surface (p, ρ,T)x or (Z, ρ,T)x in supercritical region can be satisfactory described (average relative error 0.83 %) by the equation of state in the form of polynomial decomposition of compressibility factor Z = p/RT to the series of degrees of density and temperature: \(Z=1+\sum_{i=1}^{m}\sum_{j=0}^{n_i}a_{ij}\omega^i/\tau^j\), where \(\omega=\rho_m/\rho_{m_{cr}}, \tau=T/T_{cr}\)
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ГОСТ
7.0.100-2018
<i>p</i>, ρ, <i>T</i>, <i>x</i>-dependences for supercritical water—aliphatic alcohol mixtures / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 11-38. - DOI:
TRANSLIT
p, ρ, T, x-zavisimosti sverhkriticheskih vodnyh rastvorov alifaticheskih spirtov / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 11-38. - DOI:
En
<i>p</i>, ρ, <i>T</i>, <i>x</i>-dependences for supercritical water—aliphatic alcohol mixtures. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 11-38 (2013). https://doi.org/
Key words: supercritical fluids, oil cracking, aqueous-hydrocarbon fluids, growth of quartz crystals, synthetic inclusions, oil, hydrocarbon gases, solid bitumen, thermobarogeochemistry of fluid inclusions
An experimental research was conducted to study the features of the hydrocarbons behaviour and their phase states at temperatures from 220 up to 500 °C and saturated vapour pressure and above (up to 150 MPa). The study was realized using the synthetic fluid inclusions in the quartz crystals which had been grown simultaneously with the interaction between the water solutions and crude oil. It was shown that the aqueoushydrocarbonic fluids generated at temperatures below 320 °C (approximate pressure of 30—50 MPa), depending on the thermobaric parameters and ratio of the water solution (L1), oil (L2) and the gas phase (G) (presented by water vapour), could exist as the three-phase (from L1>G≥L2 up to L2≥L1>G) and two-phase (from L1≥L2 up to L2≥L1) states. The cracking of oil in such aqueous-oil fluids is not observed. The fluids formed at temperatures above 330 °C (and especially at 380—450 °C) have higher amount of light oil fractions, gaseous hydrocarbons and residual solid bitumen. This means that the hydrocarbons in the hydrothermal systems are exposed to the cracking at the specified temperatures. Reheating of such multi phase inclusions to temperatures 240—280 °C leads to the complete dissolution of the liquid hydrocarbons in the gaseous and aqueous phases. Therefore, the fluid becomes bi phasic (water solution + gaseous hydrocarbons saturated by liquid hydrocarbons). The consecutive increase of temperature from 350 up to 380 °C transfers the fluid in homogeneous liquid or gaseous state, or in supercritical state. Fluid cooling results in its heterogenization, and all intermediate phases are consecutively restored. As a whole, the experimental studies confirm influence of the hydrocarbons cracking on the occurrence in the earth interior of the vertical zonal distribution of various types of the oil-and-gas deposits.
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ГОСТ
7.0.100-2018
On the causes of vertical zoning in hydrocarbon distribution in earth interior: experimental evidences of crude oil cracking in high-temperature aqueous-hydrocarbon fluids / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 39-60. - DOI:
TRANSLIT
O prichinah vertikal'noj zonal'nosti raspredeleniya uglevodorodov v nedrah zemli: eksperimental'nye dokazatel'stva krekinga syroj nefti v vysokotemperaturnyh vodno-uglevodorodnyh flyuidah / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 39-60. - DOI:
En
On the causes of vertical zoning in hydrocarbon distribution in earth interior: experimental evidences of crude oil cracking in high-temperature aqueous-hydrocarbon fluids. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 39-60 (2013). https://doi.org/
Key words: supercritical fluid extraction, liquid and supercritical carbon dioxide, spent nuclear fuel reprocessing, complexation, tributyl phosphate, aqueous Fe(III) nitrate solutions
Solubility of UO2(NO3)2-tributyl phosphate (TBP) complex in liquid and supercritical (SC) carbon dioxide as a function of temperature and pressure is measured. This complex is formed during the dissolution of uranium oxide in two-phase system consisting of aqueous iron nitrate solution and liquid or supercritical CO2 saturated with TBP. Kinetics of ceramic UO2 dissolution in such two-phase solvent is studied. The feasibility of the recovery of uranium from spent oxide nuclear fuels via its dissolution in sub-acid iron nitrate aqueous solutions accompanied by simultaneous extraction of the above mentioned complex into «TBP — SC-CO2» phase is demonstrated.
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ГОСТ
7.0.100-2018
Dissolution of oxide nuclear fuel in sub-acid ferric nitrate solutions and extraction of uranium from it using tributyl phosphate-containing supercritical carbon dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 61-67. - DOI:
TRANSLIT
Rastvorenie oksidnogo yadernogo topliva v slabokislyh rastvorah nitrata zheleza(III) i izvlechenie iz nego urana s pomoshch'yu sverhkriticheskogo dioksida ugleroda, soderzhashchego tributilfosfat / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 61-67. - DOI:
En
Dissolution of oxide nuclear fuel in sub-acid ferric nitrate solutions and extraction of uranium from it using tributyl phosphate-containing supercritical carbon dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 61-67 (2013). https://doi.org/
Key words: supercritical carbon dioxide, extraction, solubility, water droplets, diffraction pattern, diameter of the water droplets
The formation of water droplets of micron size in supercritical carbon dioxide (SC-CO2) in high-pressure cell with sapphire windows is studied experimentally using in situ laser diffractometry. According to the analysis of diffraction patterns of laser radiation scattered on water droplets in SC-CO2 and optical microscopy data at 10.0 MPa and 40 °C, the mean diameter of water droplets is 55±3 mm.
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ГОСТ
7.0.100-2018
Experimental study of water (micro) droplets formation from its saturated solution in supercritical carbon dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 68-76. - DOI:
TRANSLIT
Eksperimental'noe issledovanie obrazovaniya (mikro)kapel' iz rastvora vody v sverhkriticheskom diokside ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 68-76. - DOI:
En
Experimental study of water (micro) droplets formation from its saturated solution in supercritical carbon dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 68-76 (2013). https://doi.org/
Key words: aqueous solutions of NaF and Li2CO3, salt solubility and critical phenomena in binary and ternary systems
Experimental studies of binary and ternary water-salt systems containing NaF or Li2CO3 demonstrate that these salts belong to the type 2, which is characterized by negative temperature coefficient of salt solubility in water, by critical phenomena in salt-saturated aqueous solutions and by a wide region of fluid equilibria where homogeneous supercritical fluid solutions are stable at any pressure variation. However, the behavior of these two salts of type 2 differs from that of alkali metals sulfates and carbonates, which is complicated by immiscibility phenomena in stable and metastable states. It is shown that the immiscibility phenomena in hydrothermal binary systems with NaF and Li2CO3 are absent and the second critical end-point Q in solid saturated solutions appears at very high temperature and pressure (above 500 °C and 150 MPa).
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ГОСТ
7.0.100-2018
Solubility of NaF and Li<sub>2</sub>CO<sub>3</sub> (salts of type 2) in supercritical water and aqueous electrolyte (NaCl, Na<sub>2</sub>WO<sub>4</sub>, Li<sub>2</sub>SO<sub>4</sub>) solutions / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 77-83. - DOI:
TRANSLIT
Rastvorimost' solej 2-go tipa NaF i Li2CO3 v vode i vodnyh rastvorah elektrolitov (NaCl, Na2WO4, Li2SO4) pri sverhkriticheskih parametrah / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 77-83. - DOI:
En
Solubility of NaF and Li<sub>2</sub>CO<sub>3</sub> (salts of type 2) in supercritical water and aqueous electrolyte (NaCl, Na<sub>2</sub>WO<sub>4</sub>, Li<sub>2</sub>SO<sub>4</sub>) solutions. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 77-83 (2013). https://doi.org/
Key words: supercritical carbon dioxide, polylactide, atomic force microscopy of polymers
Microstructure and properties of amorphous D,L-polylactide processed different routes in supercritical carbon dioxide (SC-CO2) are studied. Atomic force microscopy analysis demonstrated polymer plasticization that follows its swelling in SC-CO2 and leads to significant internal structure changes caused by polylactic acid supramolecular transformations. A developed pore structure formation and an accompanying increase of polylactide void volume are directly related to a destruction of initial intermolecular polymer bonds during the release of carbon dioxide. These changes are reflected in significant (1.7—5-fold) increase of exothermal effects detected by differential scanning calorimetry in the temperature ranges between -30 °C and -10 °C and around 30—40 °C.
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ГОСТ
7.0.100-2018
Morphological changes of polylactic acid microstructure processed with supercritical carbon dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2013. – Т. 8. – № 2. – С. 84-93. - DOI:
TRANSLIT
Morfologicheskie izmeneniya mikrostruktury polimolochnoj kisloty pod dejstviem sverhkriticheskogo dioksida ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2013. – Т. 8. – № 2. – S. 84-93. - DOI:
En
Morphological changes of polylactic acid microstructure processed with supercritical carbon dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 84-93 (2013). https://doi.org/