Phase Diagram Of Ternary System Research Articles

Determination and molecular simulation of ternary solid–liquid phase equilibrium of succinic acid + maleic acid + water from 283.15 K to 333.15 K

This study used the isothermal saturation gravimetric method to examine the solid–liquid phase equilibrium relationships composed of succinic acid + maleic acid + water spanning from 283.15 K to 333.15 K. The experimental data were utilized for the purpose of plotting the equilibrium phase diagrams of ternary systems in the studied temperature range. There were three crystalline regions in each isothermal ternary phase diagram, two saturation boundary curves, and a co-saturation point. To broaden the use of data from binary and ternary phase equilibrium measurements, Wilson and NRTL models were utilized for correlation and expectation, while relative average deviation (RAD) and root mean square deviation (RMSD) were utilized to evaluate the computational exactness. The results show that the theoretically calculated values were found to be in near agreement with the experimental values, and both models were able to obtain more precise theoretical data under different experimental conditions. In addition, molecular simulation was employed to elucidate the interaction between succinic acid, maleic acid, and water. This study provides accurate and reliable data for the separation of succinic acid and maleic acid mixture in water. These findings can be utilized to make sense of the dissolvability conduct of succinic acid and maleic acid in aqueous solution.

Solubility Phase Diagrams of ternary systems of CsCl–CdCl2–H2O and CsBr–CdBr2–H2O at T = 298.1 K and the thermodynamic properties of the new solid phase compounds

Using an isothermal equilibrium method, thephaseequilibrium of the ternary systems CsCl–CdCl2–H2O and CsBr–CdBr2–H2O were studied at T = 298.1 K. In thephasediagram of the system CsCl–CdCl2–H2O, the solidphasesof CsCdCl3 and Cs2CdCl4, besides CsCl and CdCl2·2.5H2O, were discovered. Thephasediagramof the system CsBr–CdBr2–H2O contains five crystallization fields for the solidphases CdBr2·4H2O, CsCdBr3, Cs5Cd2Br9, Cs3CdBr5 and CsBr. The new solidphasesof CsCdCl3 and CsCdBr3 are congruently soluble, and Cs2CdCl4, Cs5Cd2Br9 and Cs3CdBr5 are incongruently soluble in the aqueous system. The experimental solubility data and phase diagrams for the ternary systems show more practical application for the obtained cadmium-based halide perovskite. The five new solid phase have been analyzed by X-ray diffraction and thermogravimetry/derivative thermogravimetry. By measuring the standard molar enthalpies of solution of the compounds, the standard molar enthalpies of formation of CsCdCl3, Cs2CdCl4, CsCdBr3, Cs5Cd2Br9, Cs3CdBr5 were determined to be –(873.3 ± 0.7) kJ·mol−1, –(1325.6 ± 0.9) kJ·mol−1, –(742.8 ± 0.7) kJ·mol−1, –(2710.0 ± 1.3) kJ·mol−1 and –(1558.1 ± 1.0) kJ·mol−1, respectively.

High-throughput experiment for the rapid screening of organic phase change materials

An emerging dynamic calorimetry method based on infrared thermography (IRT method) has recently proven to be of great interest for the fast establishment of the phase diagrams of binary systems of organic materials (sugar alcohols, fatty acids, fatty alcohols). The methods allowed for their determination in a single 2-h experiment when standard techniques require weeks of measurements hence enabling a significant improvement of the efficiency of material screening processes. As adding a component to the system greatly increases the number of compositions to be studied (21 for binary, 231 for ternary assuming a 5 mol% increment between compositions), the IRT method may be of even greater use with increasing system complexity. This work then aims at studying the applicability of IRT for the fast establishment of phase diagrams of ternary systems with the lauric (LA), myristic (MA), and palmitic (PA) fatty acids ternary system as an illustrative case. A phase diagram in agreement with the results of the literature and with DSC measurements is established using IRT in a few hours-experiments instead of weeks to months with standard methods. The obtained results (e.g.67 mol%LA + 23 mol%MA + 10 mol%PA for the eutectic composition, occurrence of a ternary eutectic reaction at 32 °C) are promising. This technique also successfully allows for rapid exploration of the phase diagram: reconstruction of the liquidus surface, identification of the eutectic transition, 4-phase equilibrium. IRT is a particularly interesting high-throughput characterization method for the establishment of the phase diagrams of ternary (or higher-order) systems.

Solid-liquid phase equilibria of the quaternary system Na+//Cl−, NO3−, SO42−-H2O at 358.15 K

The stable (solid + liquid) phase equilibrium and the solution density of the quaternary system Na+//Cl−, NO3−, SO42−-H2O and its subsystems at 358.15 K were determined by the isothermal solution saturation method and moist residues. All phase diagrams of ternary systems for Na+//Cl−, SO42−-H2O, Na+//Cl−, NO3−-H2O, Na+// NO3−, SO42−-H2O at 358.15 K contain one invariant point, two invariant curves, and three crystallization regions. Neither double salt nor solid solution is found in the three ternary systems at 358.15 K. When NaCl, NaNO3, and Na2SO4 are analyzed as (7.02, 48.62, 1.58) wt %, respectively, the quaternary system Na+//Cl−, NO3−, SO42−-H2O reach saturation at 358.15 K. The phase diagram of the quaternary system at 358.15 K includes one invariant point, three invariant curves, and three crystallization regions. The three crystallization regions correspond to NaCl, NaNO3, and Na2SO4 and the Na2SO4 crystallization region is much bigger than that of the other two salts. Moreover, using the “translation technology”, the phase diagram of Na+//Cl−, SO42−, NO3−-H2O system can be predicted and constructed. All experimental data, especially the crystalline regions, can provide the fundamental basis for the design and optimization of the crystallization process of NaCl, NaNO3, and Na2SO4 in coal chemical high salinity wastewater.

Thermodynamic modeling and phase diagram prediction of salt lake brine systems II. Aqueous Li+-Na+-K+-SO42− and its subsystems

Predicted result of complete structure phase diagram of Li 2 SO 4 -Na 2 SO 4 -H 2 O system at temperature ranging from eutectic point 251.19–373.15 K: P1, P2, P3, P4, P5 are Transition points of three solid co-saturated in the ternary system. • Thermodynamic model of aqueous Li+-Na+-K+-SO 4 2− systems across entire temperature range. • Predicting the polythermal full structure phase diagram of ternary and quaternary aqueous system.. • The multi-objective optimization method to obtain solid constants and liquid parameters. It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component, multi-temperature and high concentration. The essential subsystem of sulfate type brine, aqueous Li + -Na + -K + -SO 4 2− and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model. Liquid parameters ( Δ g IJ , Δ h IJ , and Δ C p , I J ) associated with the contributions of Gibbs energy, enthalpy, and heat capacity to the binary interaction parameters, i . e . the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression, are determined via multi-objective optimization method. The solid constants Δ f G k ° ( 298.15 ) and Δ f H k ° ( 298.15 ) of 11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities. The modeling results show the accurate representation of (1) solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K; (2) isothermal phase diagrams for Li 2 SO 4 -Na 2 SO 4 -H 2 O, Li 2 SO 4 -K 2 SO 4 -H 2 O and Na 2 SO 4 -K 2 SO 4 -H 2 O ternary systems. The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.

Analysis of the geometric features of T-x-y diagrams with melt immiscibility for silicate systems

Analysis of the geometric structure of phase diagrams for ternary systems with the two immiscible liquids has been carried out. T-x-y diagrams with the both types of the monotectic equilibriums (univariant and invariant ones) have been analyzed. Three-dimensional computer models of T-x-y diagrams for the four silicate systems with mono- and invariant equilibriums and different variants of the immiscibility surfaces location have been built. T-x-y diagram of the ZrO2-SiO2-Al2O3 system includes one immiscibility cupola, located in the ZrO2 crystallization field, which adjoins the ZrO2-SiO2 side. The 3D model of T-x-y diagram includes four invariant transformations: peritectic P: L+ZrO2+SiO2→R2, quasi-peritectic Q: L+ZrO2 →R1+R2, two eutectic E1: L→ZrO2+Al2O3+R1, E2: L→SiO2+R1+R2. Five surfaces of liquidus, which correspond to the beginning of primary crystallization of three initial components and two binary compounds R1=3Al2O3·2SiO2 and (congruently melting) and R2=ZrO2·SiO2 (decomposed without liquid) are formed in the system. T-x-y diagram TiO2-ZrO2-SiO2 is characterized by one eutectic E: L→TiO2+SiO2+ZrO2·TiO2 and one quasi-peritectic Q: L+ZrO2→SiO2+ZrO2·TiO2 transformations and includes two immiscibility surfaces from the sides of TiO2-SiO2 and ZrO2-SiO2 binary systems. FeO-SiO2-Fe2O3 system with common immiscibility cupola, that prolongs from the system FeO-SiO2 to the system SiO2-Fe2O3, is characterized by three invariant transformations of eutectic type, and one metatectic transformation V: B1 →L+B2+C, which corresponds to the transfer from high-temperature allotropy of silica (B1 - cristobalite) to the low-temperature one (B2 – tridymite). T-x-y diagram KAlSi2O6-Fe2SiO4-SiO2 has two immiscibility surfaces: one of them adjoins to the Fe2SiO4-SiO2 binary system and the second one is located on the Fe2SiO4 and tridymite liquidus surfaces, dividing the univariant curve on their boundary into two parts, and has three points of the maximum and three points of the minimum. Using of the computer models of T-x-y diagrams allows you to take into account different variants of the geometric structure of the investigated silicate systems.

Measuring boundaries in phase diagrams of ternary systems using titration calorimetry

This paper demonstrates how isothermal titration microcalorimetry (ITC) can be used for the global construction of several kinds of phase diagrams for ternary systems at 298.15 K and atmospheric pressure. The solid-solid-liquid system of KCl-KNO3-H2O has not yet been studied using ITC, and thus, it is the main system discussed. It is clear that thermal effects associated with transformations in a system (appearance or disappearance of a phase) change with the composition of the system in ampoule. During titration, the solubility curves (including the liquid-liquid and solid-liquid equilibrium lines) in ternary systems can be detected as changes in the slope of the heat evolved vs time plot or in the slope of the observed heat vs solvent concentration plot. ITC is more precise and repeatable than the visual-cloud-point method. This isothermal and isobaric titration method can also provide additional information regarding the dissolution heat and the dilution heat. On the basis of the three experimental solubilities of KCl, KNO3, and KCl + KNO3 (co-saturated solution) in H2O, the other intermediate points on the solubility curve can be obtained based on the lever rule and the assumption of ideal solution, and these results agree well with the experimental values.

Thermodynamic modeling and phase diagram prediction of salt lake brine systems. I. Aqueous Mg2+–Ca2+–Cl− binary and ternary systems

Abstract Salt lake brine is a complex salt-water system under natural environment. Although many models can express the thermodynamic properties and phase equilibrium of electrolyte aqueous solution, the multi-temperature characteristics and predictability are still the goals of model development. In this study, a comprehensive thermodynamic model system is re-established based on the eNRTL model and some improvements: (1) new expression of long-range electrostatic term with symmetrical reference state is proposed to handle the electrolyte solution covering entire concentration range; (2) the temperature dependence of the binary interaction parameters is formulated with a Gibbs Helmholtz expression containing three temperature coefficients, the liquid parameters, which associated with Gibbs energy, enthalpy, and heat capacity contribution; and (3) liquid parameters and solid species data are regressed from properties and solubility data at full temperature range. Together the activity coefficient model, property models and parameters of liquid and solid offer a comprehensive thermodynamic model system for the typical bittern of MgCl2–CaCl2–H2O binary and ternary systems, and it shows excellent agreement with the literature data for the ternary and binary systems. The successful prediction of complete phase diagram of ternary system shows that the model has the ability to deal with high concentration and high non-ideality system, and the ability to extrapolate the temperature.

Влияние электронного строения примеси на физические свойства, дефектную структуру и особенности технологии легирования кристаллов ниобата лития

Macro- and microstructure were researched for doped LiNbO3 crystals. The transmission spectra and the effective distribution coefficients of the dopant were studied. The analysis of literature data on ternary phase diagrams of systems Li2O-Nb2O5-dopant oxide and electronic configurations of dopants has revealed a possibility to predict technological growth conditions and quality of doped lithium niobate crystals. At this p-elements (boron) provide growth of structurally and compositionally uniform LiNbO3 crystals without incorporation of a dopant into the structure. Metals, s- and d-elements (magnesium and zinc) influence the melts and the crystal properties similar. At this non-periodical domain structures and similar types of point defects appear. Metals of f-elements (cerium) order the melt structure in such a way that provide forming of growth regular domain structure in LiNbO3 crystals due to their electron configurations. Keywords: crystal, lithium niobate, doping, optical microscopy.

Liquid-liquid equilibria for (volatile fatty acids + water + alcohol ethoxylates): Experimental measurement of pseudo-ternary systems

Abstract Experiments were conducted to establish the phase diagrams for ternary systems containing (acetic acid or propionic acid or butyric acid + water + alcohol ethoxylate surfactant) at 308.15 K and ambient pressure. Results indicated that the systems belong to Type 1 Treybal classification with water–surfactant binary pair exhibiting partial miscibility. The liquid–liquid equilibrium data were used to determine the ability of the surfactant to extract the acids from aqueous solutions. The calculated distribution coefficients and separation factors indicated that the effectiveness of the surfactant to extract acids follow the trend: butyric acid > propionic acid > acetic acid. The effectiveness of the surfactant to extract butyric acid from aqueous solutions is similar to previously studied environmentally-friendly solvents with added benefit of being non-inhibitory to microbial growth and metabolism. These characteristics of the alcohol ethoxylate used in this study could be exploited for the development of an extractive butyric acid fermentation process.

Phase Equilibria in the Aqueous Ternary System (NH4)2SO4 + Na2SO4 + H2O at T = (303.15 and 313.15) K and p = 0.1 MPa

The solubility for the aqueous ternary system (NH4)2SO4 + Na2SO4 + H2O at T = (303.15 and 313.15) K and p = 0.1 MPa was investigated experimentally with the method of isothermal dissolution equilibrium. In the phase diagram of the ternary system at 303.15 K, there are eight crystallization regions, four univariant curves, and three invariant points corresponding to (Na2SO4·10H2O + Na2SO4), (Na2SO4 + Na2SO4·(NH4)2SO4·4H2O), and (Na2SO4·(NH4)2SO4·4H2O + (NH4)2SO4). However, in the phase diagram of the same ternary system at 313.15 K, the crystallization region of Na2SO4·10H2O is disappeared, and there are three single salt crystallization regions corresponding to Na2SO4, Na2SO4·(NH4)2SO4·4H2O, and (NH4)2SO4. A comparison of the phase diagrams for this ternary system at (273.15, 288.15, 298.15, 303.15, 313.15, and 333.15) K shows that the area of Na2SO4·(NH4)2SO4·4H2O and (NH4)2SO4 is increased obviously, whereas the area of Na2SO4 (or Na2SO4·10H2O) is decreased significantly and no solid solution was found....

Evaluation of Cyclic Durability in Surfacemodified Layers with TiNiZr Thermoelastic Phase Transformations

This paper estimated longevity and damaging of surface materials modified by alloys with thermoelastic phase transformations, taking into account: the energy consumed for the formation of failure micro-surface in one cycle, in terms of the shape of the hysteresis loop; energy intensity of the alloy, in the light of phase composition by the results of X-ray diffraction analysis. The energy intensity and theoretical strength of ternary TiNiZr systems are calculated and plotted according to thermodynamic characteristics and phase diagrams of ternary systems. This paper carried out tests of steels with surface-modified TiNiZr layers under conditions of multicyclic fatigue and frictional friction.

Evaluation of Cyclic Durability in Surfacemodified Layers with TiNiZr Thermoelastic Phase Transformations

This paper estimated longevity and damaging of surface materials modified by alloys with thermoelastic phase transformations, taking into account: the energy consumed for the formation of failure micro-surface in one cycle, in terms of the shape of the hysteresis loop; energy intensity of the alloy, in the light of phase composition by the results of X-ray diffraction analysis. The energy intensity and theoretical strength of ternary TiNiZr systems are calculated and plotted according to thermodynamic characteristics and phase diagrams of ternary systems. This paper carried out tests of steels with surface-modified TiNiZr layers under conditions of multicyclic fatigue and frictional friction.

Phase Relations in Ternary Systems in the Subsolidus Region: Methods To Formulate Solid Solution Equations and To Find Particular Compositions

A good understanding of ternary phase diagrams is required to advance and/or to reproduce experimental research in solid-state and materials chemistry. The aim of this paper is to describe the solutions to problems that appear when studying or determining ternary phase diagrams. A brief description of the principal features shown in phase diagrams of ternary systems in the subsolidus region is included. We present a systematic procedure to obtain specific compositions of particular interest as well as to calculate binary and ternary ratios of compounds inside the Gibbs triangle and a step-by-step methodology to formulate solid solution equations in binary, ternary, or higher-composition compounds. Specific problems and their solutions are presented as a practical guide, linking the learned concepts with their applications in ceramics and solid-state chemistry research. In addition, ready-to-go exercises with worked-out solutions are included for practice. The procedures described herein may be helpful to those interested in phase diagram interpretation, preparation, and analysis.

Phase diagrams for the M2MoO4–Ln2(MoO4)3–Hf(MoO4)2 systems, where M = Li–Cs, Tl and Ln = La–Lu

In this paper, the results of systematic studies of complex molybdate systems M2MoO4–Ln2(MoO4)3–Hf(MoO4)2 (M = Li–Cs, Tl; Ln = La–Lu) are presented. Subsolidus phase diagrams of ternary systems were constructed and new triple molybdates were obtained. The optimum synthesis conditions for poly- and monocrystalline form were determined. According to single-crystal data, the structure of one of the representatives of triple molybdates was determined.

Selection of microemulsion composition via study of phase behavior for synthesis of stable monodisperse platinum nanoparticles and optimization of experimental parameters

ABSTRACTMonodisperse platinum nanoparticles were synthesized by microemulsion technique. Feasibility of formation of microemulsion with chosen proportions of components is a common problem with this method. Here, prior to preparation of microemulsion for synthesis purpose, systematic study was carried to check the suitability of selected microemulsion system by establishing phase diagram for ternary system at constant temperature on triangular coordinates. Temperature dependency of microemulsion was studied by preparing phase diagram of temperature against mass fraction of aqueous phase in ternary mixture. Both these triangular coordinate diagram at constant temperature and temperature dependency plots helped to choose proper concentrations of components in the system. Effects of molar concentration of water-to-surfactant ratio, platinum salt concentration, continuous oil phase concentration, and presence of cosurfactant with surfactant on particle size were investigated for selected system of components. Synthesized platinum nanoparticles were characterized by dynamic light scattering and transmission electron microscope. Light backscattering profiles obtained by Turbiscan were used to judge the stability of microemulsions. Further, partial weightage of affecting parameters on size of synthesized particle were studied by Taguchi orthogonal array method.

Solid–Liquid Equilibria in the Ternary Systems NaCl–SrCl2–H2O and KCl–SrCl2–H2O at 348 K

Solid–liquid equilibria in the ternary systems NaCl–SrCl2–H2O and KCl–SrCl2–H2O at 348 K were measured by the isothermal solution saturation method. The composition of the equilibrium solid phase, solubilities of salts, and densities of saturated solution in the two systems were determined. Phase diagrams of ternary systems were plotted according to experimental data. They both contained one invariant point, two univariant curves, and two regions of crystallization. Respectively, univariant curves of the corresponding equilibrium solid phase were sodium chloride (NaCl) and strontium chloride dihydrate (SrCl2·2H2O) in the ternary system NaCl–SrCl2–H2O, and potassium chloride (KCl) and strontium chloride dihydrate (SrCl2·2H2O) in the ternary system KCl–SrCl2–H2O. The two ternary systems belong to the simple type, and neither double salts nor solid solution was found. The density transformation rules were simply discussed. Simultaneously, the solubilities and density data were compared with the experimental ...

Metastable phase equilibria in the aqueous ternary system (Na2SO4 + Li2SO4 + H2O) at 308.15 and 348.15 K

The solubility and density of the metastable phase equilibria in the aqueous ternary system (Na2SO4+Li2SO4+H2O) at 308.15 and 348.15K were determined using the isothermal evaporation method. On the basis of the experimental data, the metastable phase diagrams and the diagrams of density property versus composition in the system at 308.15 and 348.15K were plotted. In the metastable phase diagram of the ternary system at 308.15K, there is four crystallization regions corresponding to thenardite (Na2SO4, Th), double salt 1 (Li2SO4·3Na2SO4·12H2O, Db1), double salt 2 (Li2SO4·Na2SO4, Db2), and lithium sulfate monohydrate (Li2SO4·H2O, Ls), four univariant curves, and three invariant points of the ternary system corresponding to (Th+Db1), (Db1+Db2) and (Db2+Ls). However, in the metastable phase diagram of the same ternary system at 348.15K, the crystallization region of Db1 is disappeared, and there is only three crystallization regions corresponding to thenardite Th, Db2 and Ls. A comparison of the metastable phase diagrams for the ternary system at 308.15 and 348.15K shows that the area of Th is increased whereas the area of Ls is decreased obviously and no solid solution was found. The solution density of the metastable ternary system at two temperatures changes regularly with the increasing of lithium sulfate concentration.

Phase diagrams for ternary systems having clathrate hydrates and vapor-liquid equilibria (simulation and experiment)

Models of T-x1-x2 phase diagrams where binary and ternary intermediate phases of stoichiometric or variable composition are formed by vapor-liquid syntectic reactions were considered. Phase transformation schemes for such the systems are presented, as well as vertical sections and isothermal sections in various interinvariant ranges.

Microchannel edge refractometry

The objective of the paper is to present an optical technique that allows to characterize in situ concentration fields in microfluidic systems. The technique is based on the measurement of the refraction index in the liquid phase, in the immediate vicinity of the walls that confine the fluids. We call this method microchannel edge refractometry. The method is non-intrusive. We describe the refractometry technique, using theory, numerics and experiments. We show a resolution and sensitivity on the order of 3×10−3 and 2×10−3, respectively. We apply the technique to analyze diffusion phenomena in T sensors, measure supersaturations and establish phase diagrams of ternary systems in dedicated microdevices.