Topological transformation of the phase diagram of the lithium nitrate-water-acetonitrile ternary system within the range of −20 to 50°C

Phase equilibria and critical phenomena in the lithium nitrate-water-acetonitrile ternary system were studied by a visual polythermal method within the range of ?20 to 50°C. In this ternary system, the constituent liquid binary system is characterized by phase separation with an upper critical solution temperature. It was found that the ternary system undergoes phase separation at temperatures below 0.7°C. In the phase diagram within the range of ?1.1 to 0.7°C, a closed phase separation region with two critical points was revealed. The temperature of the formation of the critical tie line of the monotectic state the solid phase of which is the crystalline hydrate LiNO₃ · 3H₂O was determined (?18.7°C). Depending on the concentration, lithium nitrate has both salting-in and salting-out effect on aqueous acetonitrile mixtures. The plotted isothermal sections of the temperature-concentration prism of the system at fifteen temperatures showed the pattern of the topological transformation of its phase diagram with varying temperature.     

Phase equilibria and critical phenomena in the cesium nitrate–water–pyridine ternary system

The solubilities of components, phase equilibria, and critical phenomena in the cesium nitrate–water–pyridine ternary system are studied in the 5–100°C temperature range by the visual–polythermal method. Cesium nitrate is found to exhibit a salting-out effect at temperatures above 79.9°C causing phase separation in homogeneous water–pyridine solutions. The temperature of formation of the critical monotectic tie line (79.9°C) and the compositions of solutions corresponding to the liquid–liquid critical points at three temperatures are determined. The pyridine distribution coefficients between the aqueous and organic phases of the monotectic state at 85.0, 90.0, and 100.0°C are calculated. Their values demonstrate that salting-out of pyridine from aqueous solutions by cesium nitrate increases at higher temperatures. The plotted isotherms of phase diagrams confirm the fragment of the scheme of topological transformation of the phase diagrams of salt–binary solvent ternary systems with salting-in and salting-out phenomena.     

Binary versus ternary interactions in a completely miscible three‐polymer blend system: Poly(ϵ‐caprolactone) with two different methacrylic polymers

A truly miscible ternary miscible blend consisting of poly(?‐caprolactone) (PCL), poly(phenyl methacrylate), and poly(benzyl methacrylate) (PBzMA) was discovered. The three‐polymer blend system was completely miscible within the entire composition range at ambient temperature up to about 150 °C, and ternary phase diagrams at increasing temperatures were characterized and interpreted. A ternary‐interaction model based on the modified Flory–Huggins expression was used to describe the phase diagrams with the individual binary interaction strengths. The model fitted well with the experimental‐phase diagram for the ternary blend system at T = 250 °C, where the binary PCL‐PBzMA blend system is on the critical points of phase separation. Interpretation of discrepancy between the model and experimental at other temperatures was handled with an empirical approach. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 747–754, 2002     

Equilibrium of two liquid phases and critical phenomena in a ternary system of cyclohexane-pyridine-acetic acid in the 10–55°C range

A visual polythermal method is used to study the mutual solubility of components and critical phenomena in a ternary system of cyclohexane-pyridine-acetic acid in the 10.0–55.0°C range. It is noted that the isothermal solubility diagrams of the system in the 10.0–52.5°C range is characterized by the occurrence of a closed separation region. A temperature dependence of the mixture composition, which corresponds to the critical point of solubility, is determined. It is found that with the increase in the temperature a two-liquid phase region disappears through a non-critical point.     

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 separation temperatures in the ternary system polystyrene/poly(α-methyl styrene)/cyclopentane

Phase separation temperatures of the ternary system polystyrene (PS) (M_w = 1.67 × 10⁴)/poly(α-methyl styrene) (PαMS) (M_w = 9.0 × 10⁴)/cyclopentane with a blend ratio PS/PαMS = 55/45 have been determined over the polymer concentration range 0.02 ≤ ψ_{PS + PαMS} ≤ 0.52, where ψ _{PS + PαMS} is the segment fraction of polymer in ternary system. Phase separation temperatures for the upper critical separation in the ternary system decrease with increasing ψ _{PS + PαMS} over the range 0.1 ≤ ψ _{PS + PαMS} ≤ 0.52. The vapor—liquid equilibrium in this system with a blend ratio PS/PαMS=50/50 has been determined over the concentration range 0.925 ≤ ψ_{PS + PαMS} < 0.995 and the temperature range 60–100°C by the piezoelectric vapor sorption method. The polymer—polymer interaction parameters χ′₁₂ determined are positive except at 100°C and increase with increasing ψ _{PS + PαMS}. Values of χ′₁₂ extrapolated to zero solvent concentration are positive (0.0–1.3) over the temperature range measured. Phase separation behavior is discussed in terms of phase separation temperature in a ternary system and the polymer–polymer interaction parameter.     

Effect of processing conditions on gel formation in ternary cellulose acetate systems

A series of ternary systems composed of cellulose acetate (CA), N,N-dimethylacetamide (DMA), and water were prepared by varying the mixing temperature and order of component addition with increasing water content. The viscoelastic properties of the resulting ternary systems were measured using steady state and dynamic rheology. The CA/DMA/H₂O mixture formed physical gels at 17.5 and 19 wt% water concentrations after heating to 50 and 70/90 °C, respectively. Gel formation was characterized by the loss of a Newtonian plateau in the steady state as well as the transition of the elastic (G′) modulus becoming greater than the viscous (G″) modulus in the dynamic state. The order of component addition dramatically affected phase behaviour. Adding CA to the DMA/water solution resulted in lower moduli gels and the formation of a two-phase phase separated system at high nonsolvent contents in those prepared at low temperatures. The kinetics of phase separation was improved by subjecting the gels to a thermal treatment of 90 °C. In this case, the gels previously heated at 50 and 70° C showed a one-phase phase separated gel with higher viscous and elastic moduli.     

Phase equilibria in the Li2O-CdO-B2O3 system

Phase equilibria in the Li₂O-CdO-B₂O₃ ternary system were studied by X-ray powder diffraction analysis. Quasi-binary sections of the system were identified by the method of intersecting sections. An isothermal section in the subsolidus region at 650°C was constructed. The formation of one ternary phase, LiCdBO₃, was confirmed, which melts incongruently at 862°C.     

Experimental investigation and thermodynamic modeling of the Au–Ge–Ni system

Abstract  

Phase equilibria in the Au–Ge–Ni ternary system were studied by means of scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and differential scanning calorimetry. The phase relations in the solid state at 600 °C as well as a vertical section at Au₇₂Ge₂₈–Ni were established. No ternary compound was found at 600 °C. On the basis of the experimental phase equilibria data, a thermodynamic model of the Au–Ge–Ni ternary system was developed using the CALPHAD method. Thermodynamically calculated phase diagrams are shown at 600 °C, in two vertical sections and the liquidus projection. Reasonable agreement between the calculations and the experimental results was achieved.     

Selection of Polymorphic Structure in Dihydroxystearic Acid/Octyl dihydroxystearate/RBD Palm Kernel Olein & Medium Chain Triglycerides in Cosmetic and Personal Care Formulation

Dihydroxystearic acid (DHSA) and octyl dihydroxystearate (DHSA‐octyl ester) have been successfully prepared from palm oleic acid. Preliminary results showed that these compounds are suitable in personal care and cosmetics products. The objective is to study the phase behaviors in ternary system of DHSA/DHSA‐octyl ester/RBD palm kernel olein (RBDPKOo) and medium chain triglycerides (MCT) at 85°C. The phase changes were observed through polarizing light while the formation of texture was confirmed using polarizing microscope combination with heating. From the ternary phase diagram, results showed that all ratios of DHSA/DHSA‐octyl ester were completely in two‐phase region with various concentrations of RBDPKOo/MCT. Needles and spherulite textures were found in this system. The viscosity and thixotropy of these mixtures were also determined using rheometer. DHSA and DHSA‐octyl ester has a melting point of 84.4°C and 64.3°C, respectively.     

Phase equilibria and critical phenomena in the cesium nitrate-water-diethylamine ternary system

Phase equilibria and critical phenomena in the cesium nitrate-water-diethylamine ternary system were studied by the visual-polythermal method over the temperature range 60–150 °C, where the boundary binary liquid system was characterized by stratification with a lower critical solution temperature (LCST). The introduction of cesium nitrate into the water-diethylamine system decreased the LCST of this system from 146.1 to 69.3°C and lowered the mutual solubility of the components. The diethylamine distribution coefficients between the aqueous and organic phases were calculated for monotectic equilibria at various temperatures. The salting out of diethylamine with cesium nitrate grew stronger as the temperature increased. The conclusion was drawn that the isotherms of the phase states of the system substantiated the generalized scheme of topological transformations of phase diagrams for salt-binary solvent ternary systems with salting out. The salting out effects of cesium and potassium nitrates on the water-diethylamine binary system were compared.     

Phase Equilibria and Critical Phenomena in the Potassium Nitrate-Water-Diethylamine Ternary System

Phase equilibria and critical phenomena in the potassium nitrate—water—diethylamine ternary system were studied by the visual polythermal method over the temperature range 40–150°C. The corresponding boundary binary liquid system was characterized by stratification with the lower critical temperature of solution. The introduction of potassium nitrate into the water—diethylamine system lowered its lower critical temperature of solution from 146.1 to 48.1°C and decreased the mutual solubility of the components. The diethylamine distribution coefficients between the aqueous and organic monotectic equilibrium phases at various temperatures were calculated. The effect of the salting out of diethylamine from aqueous solutions under the action of potassium nitrate was found to strengthen as the temperature increased. The constructed isotherms of the phase states of the system substantiated the generalized topological scheme of the transformation of phase diagrams of salt-binary solvent ternary systems with salting out.     

Phase transition temperatures of Sn–Zn–Al system and their comparison with calculated phase diagrams

The Sn?CZn?CAl system was studied in connection with the possible substitution of lead-based solders for temperatures up to 350?°C. Ternary alloys with up to 3?wt% of aluminium were prepared. The investigated alloys lie close to the monovariant line (eutectic valley) of the Sn?CZn?CAl system. The temperatures of phase transitions of six binary Sn?CZn reference alloys and fourteen ternary Sn?CZn?CAl alloys using DTA method were investigated in this paper. DTA experiments were performed at the heating/cooling rate of?4?°C?min^?1 using Setaram SETSYS 18_TM experimental equipment. The temperatures of phase transitions in the ternary Sn?CZn?CAl system were obtained, namely, the temperature of ternary eutectic reaction T _E1 (197.7?±?0.7?°C), temperature of ternary transition reaction T _U1 (278.6?±?0.7?°C), temperatures of liquidus and other transition temperatures for studied alloys. Temperatures obtained during DTA heating runs were used as authoritative. DTA curves obtained during cooling enabled realising better differentiation of the obtained overlapped heat effects (peaks) during heating. Theoretical isopleths of the Sn?CZn?CAl phase diagram were calculated using the Thermocalc software and MP0602 thermodynamic database. Experimental data were compared with the calculated temperatures, and a good agreement was obtained.     

Topological transformation of a phase diagram for the sodium nitrate-water-isopropanol ternary system

Phase equilibria and critical phenomena in the sodium nitrate-water-isopropanol ternary system, where a boundary binary liquid system shows no immiscibility over the entire temperature range of its liquid state, were studied in the range from 5 to 90°C using a visual polythermal method. The formation temperature of a monotectic critical tie-line was determined to be 6.1°C, and the solution compositions corresponding to critical solution points at various temperatures were determined. Isopropanol partition coefficients between the aqueous and organic phases of monotectic equilibrium were calculated for seven temperatures. The isopropanol salting out from aqueous solutions by sodium nitrate was shown to be enhanced by rising temperature. Isothermal phase diagrams of the title system were constructed to verify a fragment of the general scheme of topological transformations of phase diagrams for salt-binary solvent ternary systems with salting out.     

K<Subscript>2</Subscript>SO<Subscript>4</Subscript>-KCl-H<Subscript>2</Subscript>O phase diagram in the area of heterogenization of homogeneous supercritical fluids

The experimental investigations of phase equilibria in the K₂SO₄-KCl-H₂O system at temperatures to 500°C and pressures to 100 MPa were directed to elucidate the phase transformation sequence that leads to the heterogenization of the supercritical fluid whose existence field propagates from the K₂SO₄-H₂O binary subsystem to the ternary system. We suggest that fluid heterogenization in the title ternary system is accompanied by the transformation of the metastable immiscibility field to stable equilibria at elevated temperatures (near 460°C) and unexpectedly high pressures (～60 MPa), despite the presence of a vapor phase.     

Phase diagram for the ternary system LiClCaCl2CaCrO4

The phase diagram for the system LiClCaCl₂CaCrO₄ has been studied using differential thermal analysis. LiClCaCl₂CaCrO₄ has been shown by X-ray diffraction to be a stable, diagonal section of the Li, Ca//Cl, CrO₄ reciprocal ternary system. The three binary systems are: LiClCaCl₂ which exhibits a double salt (LiCaCl₃), which decomposes without melting at 439°C and a eutectic at 36.3 mole % CaCl₂ (m.p. 487°C); CaCl₂CaCrO₄ which shows a eutectic at 23.4 mole % CaCrO₄ (m.p. 660°C); and LiClCaCrO₄ with a eutectic at 14.3 mole % CaCrO₄ (m.p. 538°C).In the ternary system, a eutectic exists at 63.2 mole % LiCl32.9% CaCl₂3.9% CaCrO₄ (m.p. 479°C). In addition, a four-phase equilibrium, involving all solid phases, exists at nearly all compositions at 435°C.Isotherms are shown for the liquidus surface (primary crystallization) and for the secondary crystallization surface. Isothermal and vertical sections through the ternary phase diagram are shown.     

A constitutional diagram of the system TiC−HfC−WC

The system TiC?HfC?WC was investigated by means of melting point, differential thermoanalytical, X-ray diffraction and metallographic techniques on hot pressed and heat treated as well as melted alloy specimens and a complete constitutional diagram from 1500°C through the melting range established. According to the peritectic melting of hexagonal WC both isopleths, TiC?WC as well as HfC?WC show a class II reaction at 2760°C in Ti?W?C and at 2730°C in Hf?W?C. The phase behaviour within the TiC?HfC?WC system is characterized by the presence of a (binary) miscibility gap within TiC?HfC [T _c=1780°C, (TiC)_0.55(HfC)_0.45] which extends into the ternary forming a closed ternary miscibility gap at higher temperatures with an isolated ternary critical point:T _c=1800°C, (TiC)_0.55(HfC)_0.45(WC)_0.05. Interaction of the solvus (boundary of the cubic-B 1 monocarbide solid solution) and the ternary miscibility gap was established at 1540°C and (TiC)_0.27(HfC)_0.41(WC)_0.32: Alloys of this composition enter a decomposition reaction on cooling into two isotypic cubic B 1 phases and hexagonal WC. Isothermal sections were calculated assuming regular solutions.     

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.     

Polythermal study of the salting-out of triethylamine from aqueous solutions with sodium nitrate

Visual-polythermal method was used to study, in the temperature range from ?17 to 25°C, the phase equilibria and critical phenomena in the ternary system constituted by sodium nitrate, water, and triethanolamine, in which the boundary binary system is characterized by stratification with a lower critical solution point.     

Topological transformation of the phase diagram of a potassium perchlorate-water-tetrahydrofuran ternary system in the temperature range of 40 to 140°C

Phase equilibria and critical phenomena in a potassium perchlorate-water-tetrahydrofuran ternary system are studied by visual polythermal means in the range of 40 to 140°C; the solubility diagram of the liquid subsystem is characterized by the presence of isolated binodal curve. The temperature of formation for the critical node of the monotectic state (107.3°C) and the dependences of the composition that corresponds to the critical points of solubility in the delayering field vs. temperature in the ranges of 70.3 to 107.3°C and 137.1 to 140.2°C are determined. The topological transformation of the investigated ternary system’s phase diagram upon a change in temperature is studied using isothermal sections of the system’s temperature concentration prism, plotted at nine temperatures. It is found that potassium perchlorate has only a salting-in effect on mixtures of water and tetrahydrofuran at temperatures below 107.3°C; at higher temperatures, it has both a salting-in and a salting-out effect, depending on its concentration and the composition of mixed solvent. It is shown that potassium perchlorate’s effect of salting tetrahydrofuran out of aqueous solutions grows slightly with an increase in temperature.