Phase equilibria and critical phenomena in a sodium nitrate-water-diethylamine ternary system

The phase equilibria and critical phenomena in a sodium nitrate—water—diethylamine ternary system were studied by the visual polythermal method at 10—150°C, where the frontier binary liquid system is characterized by delamination with the lower critical solution temperature (LCST). The introduction of sodium nitrate into the water—diethylamine system led to a significant decrease (from 146.1 to 22.9°C) in the LCST of the system and the mutual solubility of its components. The coefficients of the distribution of diethylamine between the water and organic phases of the monotectic equilibrium at different temperatures were calculated. The effect of the salting-out of diethylamine by sodium nitrate from aqueous solutions increased with temperature. The constructed isotherms of the phase states of the system confirmed the general scheme of the topological transformation of the phase diagrams of the salt—binary solvent ternary systems with salting-out. The results of the salting-out action of sodi um, potassium, and cesium nitrates on the water—diethylamine binary system were compared.     

Phase equilibria and critical phenomena in the rubidium nitrate-water-acetonitrile system

Phase equilibria and critical phenomena were studied from -5 to 120°C in the rubidium nitrate-water-acetonitrile system, in which the liquid binary subsystem is characterized by liquid-liquid phase separation with an upper critical solution point (UCSP), using a visual polythermal method. We found that rubidium nitrate has a salting out effect on water-acetonitrile solutions and causes them to demix at any temperature in the specified range. Acetonitrile distribution coefficients between aqueous and organic monotectic phases were calculated for various temperatures. The minimum value was observed for 20.0°C. Six isothermal phase diagrams of the system were plotted to verify a fragment of the global scheme of the topological transformation of phase diagrams for salt-binary solvent ternary systems with salting out. The salting out effects of potassium, rubidium, and cesium nitrates on water-acetonitrile mixtures were comparatively analyzed.     

Phase equilibria and critical phenomena in the potassium perchlorate-water-<Emphasis Type="Italic">n</Emphasis>-butoxyethanol ternary system

Phase equilibria and critical phenomena in the potassium perchlorate-water-n-butoxyethanol ternary system, where the boundary liquid binary system is characterized by the presence of a closed stratification region, were studied by the visual-polythermal method over the temperature range 40–150°C. The temperature of the formation of the critical monotectic equilibrium tie line (141.0°C) and temperature dependences of the compositions of mixtures corresponding to the critical solubility points of the stratification region over the temperature ranges 47.7–130.3 and 141.0–150.0°C were determined. The isotherms of phase states constructed at 10 temperatures were used to reveal the topological transformation of the phase diagram of the ternary system depending on temperature. At low concentrations (up to 5.8 wt %), potassium perchlorate had a salting in action on heterogeneous water-n-butoxyethanol mixtures. The solubility of the salt increased as the temperature grew, and, above 141.0°C, potassium perchlorate had a salting out action. The salting out of n-butoxyethanol from aqueous solutions by potassium perchlorate grew stronger as the temperature increased.     

Phase equilibria of narrowly distributed dextranes in the ternary system dextrane-water-ethanol

Neuchl, C. and Mersmann, A., 1993. Phase equilibria of narrowly distributed dextranes in the ternary system dextrane-water-ethanol. Fluid Phase Equilibria, 90: 389-398.

In this work we consider the phase equilibria of narrowly distributed dextranes with different average molecular masses in the ternary system dextrane-water-ethanol which are of interest in the fractionation of broadly distributed dextranes. It can be emphasized that the degree of polymerization of the dextrane has a great influence on the phase equilibrium in this ternary system. Numerical calculations were performed using the model of Flory and Huggins. The agreement between experimental and theoretical phase equilibria is very good. The interaction parameter of the Flory-Huggins model for the water-dextrane interaction is independent of the molecular mass of the dextrane. The interaction parameters for the water-ethanol and ethanol-dextrane interactions show a dependency on the molecular mass of the dextrane. However, both interaction parameters reach a limiting value for high molecular mass dextrane.     

Phase equilibria in ternary polymer blends

The phase states and rheological properties of blends of three polymers??polystyrene, poly(methyl methacrylate), and the styrene-acrylonitrile copolymer??in the common solvent chloroform are studied. The phase diagrams are constructed and the positions of spinodals are determined via the method of turbidity points. The effect of the third polymer on the compatibility of the binary blend obeys Prigogine??s rule; that is, it is determined by the solubility of the added polymer in the first two components. The extremum composition dependence of rheological properties of ternary polymer systems in the vicinity of the separation point (the metastable region) is found. Through the method of convex-shell construction, the phase diagrams are calculated.     

Phase equilibria in the ternary system PbO-P2O5-PbCl2

Within the ternary system PbO-P₂O₅-PbCl₂, the partial ternary system PbO-7PbO.PO_2.5.PbCl₂-Pb₁₀(PO₄)6Cl₂-Pb₈P₂O₁₃ was investigated by thermal, microscopic, X-ray, dilatometric and IR absorption analyses, and its phase diagram was established. The occurrence of new chemical compounds was not discovered.

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Zusammenfassung Mittels thermischen, mikroskopischen, röntgenografischen, dilatometrischen und IR-Absorptionsuntersuchungen wurde innerhalb des ternären Systèmes PbO - P₂O₅ - PbCl₂ das partielle ternäre System PbO - 7PbO·PO_2.5PbCl₂-Pb₁₀(PO₄)6Cl₂- Pb₈P₂O₁₃ untersucht und dessen Phasendiagramm erstellt. Die Existenz neuer chemischer Verbindungen konnte nicht festgestellt werden.

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The work presented in this paper was financed by the Polish Ministry of National Education.     

Phase equilibria in the ternary system PbO-P2O5-PbCl2

In the ternary system PbO-P₂O₅-PbCl₂, the partial system PbO-Pb₅Cl₂O₄-Pb₁₀(P04)₆Cl₂-14PbO·P₂O₅·2PbCl₂ has been examined by thermal, microscopic, X-ray, dilatometric and IR absorption analyses, and its phase diagram is reported. A new ternary compound with the formula 29PbO·3P₂O₅·6PbCl₂ has been found to occur, which is formed peritectically in the system Pb₅Cl₂O₄-Pb₁₀(PO₄)₆Cl₂ making a pseudobinary section here. X-ray identification data on the newly discovered phase are presented.

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Zusammenfassung Im ternären System PbO-P₂O₅-PbCl₂ wurde mittels thermischer, mikroskopischer, röntgenografischer, dilatometrischer und IR-Absorptionsanalyse das Teilsystem PbO-Pb₅Cl₂O₄-Pb₁₀(PO₄)₆Cl₂-d14PbO·P₂O₅·2PbCl₂ untersucht und sein Phasendiagramm erstellt. Es wurde die Existenz einer neuen ternären Verbindung mit der Formel 29PbO·3P₂O₅·6PbCl₂ gefunden, die peritektisch im System Pb₅Cl₂O₄-Pb₁₀(PO₄)₆Cl₂ geformt wird und dort einen pseudobinären Bereich bildet. Zur Identifizierung werden hier die Röntgenangaben der neu entdeckten Phase veröffentlicht.

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The author is deeply grateful to Dr. Janusz Matuszewski for his help during the X-ray examinations.     

Fluid multiphase equilibria and critical phenomena in binary and ternary mixtures of carbon dioxide, certain n-alkanols and tetradecane

Experimental results of fluid multiphase equilibria occurring in ternary mixtures of near-critical carbon dioxide, certain n-alkanols and tetradecane are presented. The following n-alkanols were used in this investigation: decanol, octanol, heptanol, hexanol and pentanol. In the ternary systems with decanol, octanol or heptanol a closed loop liquid-vapor two-phase region in the three-phase surface liquid-liquid-vapor was found. As far as the ternary system with decanol is concerned, this phenomenon is in agreement with an earlier and unexpected finding of Patton et al. (1993). In addition, it was also found in this study that the phase diagrams of the ternary mixtures with hexanol or pentanol as the n-alkanol show further complications.     

Phase equilibria in the ternary system ethyl 1,1-dimethylethyl ether+heptane+octane

Vapor–liquid equilibrium at 94 kPa has been determined for the ternary system ethyl 1,1-dimethylethyl ether (ETBE)+heptane+octane. The system deviates slightly from ideality and no azeotrope is present. The ternary activity coefficients and the boiling points of the system have been correlated with the composition using the Redlich–Kister, Wilson, NRTL, UNIQUAC, UNIFAC, and Wisniak–Tamir relations. Most of the models allow a very good prediction of the activity coefficients of the ternary system from those of the pertinent binary systems.     

Phase equilibria in the ternary system hexane+ethyl 1,1-dimethylethyl ether+heptane

Consistent vapor–liquid equilibrium data at 94 kPa have been determined for the ternary system hexane+ethyl 1,1-dimethylethyl ether+heptane. The results indicate that the system deviates positively from ideality and that no azeotrope is present. The ternary system were predicted with the composition by the Redlich–Kister, Wilson, NRTL, UNIQUAC and UNIFAC models using only the parameters of the constituent binaries. Most of the models allow a very good prediction of the phase equilibrium of the ternary system. In addition, the Wisniak–Tamir relations were used for correlating bubble-point temperatures.     

Phase equilibria in the ternary system PbO−P2O5−PbCl2

Journal of Thermal Analysis and Calorimetry - In the ternary system PbO?P2O5?PbCl2, the partial ternary system Pb5Cl2O4?Pb3Cl2O2?Pb10(PO4)6Cl2 was examined by thermal,...     

Phase equilibria in the ternary system PbO−P2O5−PbCl2

Phase dependencies in the ternary system Pb₃Cl₂O₂?PbCl₂?Pb₁₀(PO₄)₆Cl₂, which is a partial system of the ternary system PbO?P₂O₅?PbCl₂, have been investigated by thermal, X-ray phase, microscopic, dilatometric and IR absorption analyses. The phase diagram of the Pb₃Cl₂O₂?PbCl₂?Pb₁₀(PO₄)₆Cl₂ system has been provided. The components have been found not to form any new chemical compounds.     

Phase equilibria and critical phenomena in fluid (n-alkane + water) systems at high pressures and temperatures

In fluid (n-alkane + water) mixtures (gas + gas) equilibria of the second type are found. Phase equilibria in fluid (n-pentane + water) and (n-heptane + water) were measured in the temperature range 600 to 675 K and at pressures from 15 to 170 MPa. The critical curve of these systems starts at the critical point of pure water and runs through a temperature minimum with increasing pressure. Experimental results are compared with previous studies and it is found that the data fit very well within the systematics of other (n-alkane + water) systems.     

Phase equilibria in the Tl-TlBr-S system

The polythermal sections TlBr-Tl₂S, TlBr-Tl₄S₃, TlBr-TlS, and Tl₆SBr₄-Tl; the isothermal section at 300 K of the phase diagram; and the projection of the liquidus surface of the Tl-S-Br system have been investigated in the composition region Tl-TlBr-S by DTA, X-ray powder diffraction analysis, and microhardness measurements. The primary crystallization regions, including that of the only ternary compound (Tl₆SBr₄), have been determined, and the types and coordinates of the invariant and univariant equilibria in the phase diagram are determined.     

Phase equilibria in the Ag-Bi-Te system

The Ag-Bi-Te system has been investigated over the whole concentration range using DTA, powder X-ray diffraction, microhardness measurements, and measurements of the emf of concentration cells with reference to Ag/AgCl electrodes. The vertical sections Ag₅Te₃-Bi₂Te₃, AgBiTe₂-Bi(Te) and Ag-Bi₂Te, an isothermal section at 400 K, and liquidus-surface projection have been designed. The fields of crystalline phases, including the ternary compound AgBiTe₂, have been determined.     

Phase equilibria in the Cu-Tl-Ge system

The Cu-Tl-Ge system has been studied by DTA and powder X-ray diffraction. Several polythermal sections, the isothermal section at 400 K, and the liquidus surface projection have been constructed for the phase diagram of this system. Primary phase fields and the types and coordinates of invariant and monovariant equilibria have been determined. An immiscibility region of the Cu-Tl binary subsystem considerably (up to 60 at % Ge) protrudes into the triangular diagram and crosses peritectic and eutectic curves that originate from the Cu-Ge subsystem. This gives rise to a number of four-phase monotectic equilibria in the ternary system. Crystallization ends with peritectic equilibrium and eutectic equilibria, which are all degenerate in the vicinity of thallium. Intermediate ternary phases are not formed in the system. Solubilities in the initial components and in binary phases of the Cu-Ge system do not exceed 0.5 at %.     

Phase equilibria in the thiourea-benzene system

Phase equilibria in the thiourea (host)-benzene (guest) binary system with clathrate formation were studied over the temperature range 260–460 K by physicochemical analysis methods. The stoichiometry and conditions of the existence of the 2.40(±0.02)(NH₂)₂CS · C₆H₆ compound, which incongruently decomposed at 358.7 K into rhombic thiourea and the guest component, were determined. The parameters of the Bravaisrhombohedral cell of the clathrate (space group R \(\bar 3\) c) were found to be a = 15.921(6), c = 12.417(8) Å, and V = 2725(5) ų; d _calc = 1.192 g/cm³ and d _expt = 1.195(7) g/cm³. The packing of guest molecules in the rhombohedral host framework was modeled taking into account stoichiometry and unit cell parameters to show that benzene molecule planes were tilted with respect to the c channel axis with the formation of a monomolecular closely packed chain in the guest subsystem.     

Phase equilibria in the Co-Sm-B system

Metal-rich ternary alloys of the Co-Sm-B system up to a Co: B atomic ratio of 1:1 were studied to obtain an isothermal section at 800°C. Among the eight ternary compounds found in this composition range, two had not been reported previously: tetragonal Co₂₀Sm₃B with a = 0.8621 nm and c = 1.1692 nm and hexagonal Co-Sm₂B₃ with a = 0.511 nm and c = 1.273 nm. Other new information includes the Bravais lattice of Co₄SmB₄, which is tetragonal with a = 0.7038 nm and c = 1.1437 nm, and of as-cast Co₂SmB₂, which is tetragonal with a = 1.2804 nm and c = 1.4003 nm. Four of the ternary compounds are members of the homologous series Co_3n+5Sm_n+1B_2n formed by alternating one layer of Co₅Sm with n layers of Co₃SmB₂.     

Phase equilibria in the silver-dysprosium system

The Ag-Dy system has been studied by differential thermal analysis, chemical analysis and metallographic and X-ray examination. The following congruently-melting phases were observed: Ag₅₁Dy₁₄ (m.p. 990 ± 10 °C), Ag₂Dy (m.p. 980 ± 10 °C) and AgDy (1185 ± 10 °C). The following eutectics occur: Ag-Ag₅₁Dy₁₄ (800 ± 5 °C, 12.0 ± 0.5 at.% Dy), Ag₅₁Dy₁₄- Ag₂Dy (905 ± 5 °C, 28.6 ± 0.5 at.% Dy), Ag₂Dy—AgDy (950 ± 10 °C, 37.5 ± 0.5 at.% Dy) and AgDy-Dy (900 ± 10 °C, 74.5 ± 0.5 at.% Dy).The Ag-Dy phase diagram is compared with the already known diagrams of other Ag-R.E. systems, and is briefly discussed.     

Phase equilibria in the Co-Cr-Ni system

The 800°C isothermal section of the Co-Cr-Ni system was plotted using a set of physicochemical methods. The section is characterized by an extensive field of a cobalt-and nickel-based γ solid solution. The homogeneity region of the σ phase is as large as 18 at % Ni and is directed to Ni₄₀Cr₆₀. The penetration depth of the hcp ? phase does not exceed 10 at % Ni.