Al-Zn-Sn Phase Diagram Calorimetric Study of the Isobaric Invariants

A systematic study of Al-Zn-Sn ternary alloys by using a Tian-Calvet calorimeter with slow heating and cooling rate was carried out and supplemented by scanning electron microscopic observations. The results have shown that crystallization coupled with dissolution of tin into the α_ss′ ternary solid solution on heating is an endothermic process, while melting coupled with tin expulsion on cooling is an exothermic one. It seems that the thermal effects of phase transition are outweighed by much stronger ones due to a large composition change of the α_ss′ ternary phase. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermodynamic consistency of high pressure ternary mixtures containing a compressed gas and solid solutes of different complexity

A thermodynamic consistency test applicable to high pressure binary gas–solid mixtures is extended to ternary mixtures containing a compressed gas and two solid solutes. A high pressure mixture containing carbon dioxide as solvent and two chemically similar solutes (2,3 dimethylnaphthalene and 2,6 dimethylnaphthalene) and a high pressure mixture containing carbon dioxide as solvent and two chemically different solutes (capsaicin and β-carotene), are considered in the study. Several sets of isothermal solubility data for binary and ternary mixtures are considered in the study. The Peng–Robinson equation of state with the mixing rules of Wong and Sandler have been employed for modeling the solubility of the solid in the case of binary mixtures, while the classical van der Waals mixing rules were used for modeling the ternary mixtures containing two solid solutes. Then the proposed thermodynamic consistency test has been applied. The results show that the thermodynamic test for ternary mixtures can be applied with confidence determining consistency or inconsistency of the experimental data used.     

Contribution à l'étude thermodynamique du système ternaire aluminum—gallium—étain

The heats of mixing of ternary liquid aluminum—gallium—tin alloys have been measured in a high temperature microcalorimeter at 995 K. The partial free energy of aluminium of such alloys have been obtained from e.m.f. measurements.These results, combined with the thermodynamic properties of the binary systems, enable the calculation of such properties in the whole composition range from which the phase diagram is derived.     

硝酸盐型卤水体系的综合热力学模型与多温相图预测

硝酸盐型卤水是盐湖卤水、 硝酸盐工业、 废水处理中普遍遇到的电解质溶液体系. 硝酸盐具有极高的溶解度, 实现硝酸盐型复杂电解质体系物性和相平衡的精准热力学表达依然具有挑战性. 以煤化工废水的典型体系Na⁺//NO₃^- , Cl^-, SO₄^{2 -} -H₂O为对象, 以改进的eNRTL模型为基础, 由活度系数模型、 溶液物性模型、 物种热力学模型和固液相平衡模型构成了电解质体系的综合热力学模型. 利用二元体系的冰点、 饱和蒸汽压、 等压摩尔热容、 活度系数和渗透压系数等物性数据和三元体系等温相平衡数据, 采用多目标优化方法, 获得了表达研究体系的多温特性的12组液相特征参数和7个固相物种的热力学参数. 据此完成了3个二元体系、 3个三元体系等温相平衡的准确计算和三元、 四元完整相图的预测, 适用温度达到实验所及的全部温度范围(254.65~543.15 K); 适用浓度达到饱和程度, 其中NaNO₃的浓度高达226.88 mol/kg. 三元、 四元体系的多温相图预测结果与实验数据相吻合, 并给出了9个三元、 5个四元体系零变点的完整信息.     

Theoretical and Experimental Exploration of the Energy Landscape of the Quasi‐Binary Cesium Chloride/Lithium Chloride System

As a case study, the energy landscape of the cesium chloride/lithium chloride system was investigated by combining theoretical and experimental methods. Global optimization for many compositions of this quasi‐binary system gave candidates for possible modifications that constitute promising targets for subsequent syntheses based on solid‐state reactions. Owing to the synergetic and complementary nature of the computational and experimental approaches, a substantially better efficiency of exploration was achieved. Several new phases were found in this system, for the compositions CsLiCl₂ and CsLi₂Cl₃, and their thermodynamic ranking with respect to the already‐known phases was clarified. In particular, the new CsLiCl₂ modification was shown to be the low‐temperature phase, whilst the already‐known modification for this composition corresponded to a high‐temperature phase. Based on these results, an improved cesium chloride/lithium chloride phase diagram was derived, and this approach points the way to more rational and more efficient solid‐state synthesis.     

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.     

Complexation of nevirapine with β-cyclodextrins in the presence and absence of Tween 80: characterization,thermodynamic parameters,and permeability flux

The work is undertaken to evaluate the effect of Tween 80 on the complexing ability of β-cyclodextrins to encapsulate the poorly soluble antiretroviral agent, nevirapine. The phase solubility diagram indicates 1:1 stoichiometry and is supported by electronspray ionization mass spectrometry. The complexes were characterized by DSC, FT-IR, and XRD in the solid state. The ternary systems were autoclaved before being lyophilized for the best results. Proton NMR suggests that the methyl pyridine ring of the drug is involved in inclusion and enters from the wider side of the cavity which was confirmed by COESY NMR. Solution calorimetry, a direct method to determine the thermodynamic parameters, was used to determine the complexation constant (K) and other thermodynamic properties. The process is associated with negative ∆H and positive ∆S indicating a stable inclusion complex. The value of K follows the order β-CD < HP-β-CD < M-β-CD. The molar enthalpy of solution in autoclaved solid formulation is less endothermic as compared to additive molar enthalpy of solution obtained by summation of enthalpy of solution of individual components suggesting synergistic interaction between the drug and its constituents. A threefold increase of the in vitro permeability flux was observed for binary systems which was elevated to fourfold for autoclaved ternary complexes.     

The Al-Zn-Ga Phase Diagram Part I

The Al-Zn-Ga ternary phase diagram was earlier established by thermodynamic modellization [1], but no experimental study appears to have been carried out on this system, except for measurements of mixing enthalpies in the liquid [2]. The present experimental study was carried out by thermal analysis and X-ray diffraction at various temperatures, using the isopletic cuts method. Four isopletic cuts were established and two others were partly studied in the Al-rich corner of the diagram. On these cuts, two isobaric ternary invariant reactions were determined: a eutectic reaction at 23±1°C, and a metatectic reaction at 123±1°C. Evidence was found for the existence of a retrograde miscibility of Ga in a solid solution α′_SS which protrudes into the ternary system starting from the Al-Zn binary up to a Ga concentration of about 30%^*. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermodynamic properties of the binary mixture of water and <Emphasis Type="Italic">n</Emphasis>-butanol

The molar heat capacities of the binary mixture composed of water and n-butanol were measured with an adiabatic calorimeter in the temperature range 78–320 K. The functions of the heat capacity with respect to thermodynamic temperature were established. A glass transition, solid–solid phase transition and solid–liquid phase transition were observed. The corresponding enthalpy and entropy of the solid–liquid phase transition were calculated, respectively. The thermodynamic functions relative to a temperature of 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.     

Phase Equilibria in the Ag–In–Pd System at 700°C

Phase equilibria in the Ag–In–Pd system were determined at 700°C based on experimental results for 21 alloys. A ternary compound T₁ (with the approximate composition AgInPd₂) was identified by XRD analysis. These data were compared with the results of a CALPHAD-type prediction, based on binary thermodynamic data only and a symmetrical Redlich–Kister–Muggianu model. The experimental results will serve as a basis for refined thermodynamic modeling of the different phases in this ternary system.     

Etude du Systeme Ternaire Se-Te-Sn

This work is a part of the systematic study of the ternary based chalcogenides systems. The aim is to determine the phase equilibrium, and to determine the limits of the phase area. This is done in view to perfecting knowledge of elaboration conditions for new materials and to study of their physical properties. Few works have been devoted to the study of the ternary system Se-Te-Sn, only the cross section SnSe-SnTe has been studied [1] and [2]. The experimental study by DTA, DSC and X-ray diffraction on powder performed at room temperature, exhibits a miscibility gap in the liquid state which narrows as it goes through the Sn-Se binary system. Three cross sections behave as ‘quasi-binary‘ system and six ternary invariants have been exhibited: three ternary eutectics and three ternary quasi-peritectics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Phase Equilibria in the Ag–In–Pd System at 700°C

Summary. Phase equilibria in the Ag–In–Pd system were determined at 700°C based on experimental results for 21 alloys. A ternary compound T₁ (with the approximate composition AgInPd₂) was identified by XRD analysis. These data were compared with the results of a CALPHAD-type prediction, based on binary thermodynamic data only and a symmetrical Redlich–Kister–Muggianu model. The experimental results will serve as a basis for refined thermodynamic modeling of the different phases in this ternary system.     

Phase equilibria in water-(1-, 2-, <Emphasis Type="Italic">iso</Emphasis>-)butanol-18-crown-6 systems

We present the results from measuring the solubility of 18-crown-6 in isobutanol in the temperature interval of 280–308 K and information about liquid-liquid equilibria in water-(1-, 2-, iso-)butanol-18-crown-6 systems at 298 K. The parameter values of the extended UNIQUAC model were determined on the basis of information about the thermodynamic properties and phase equilibria in the binary systems. It is shown that we must use parameters of ternary interaction in addition to binary parameters to adequately describe the miscibility gap on the basis of the results of turbidimetric titration in ternary water-(1-,2-, iso)butanol-18-crown-6 systems.     

Comparison of Prediction of Phase Equilibria in the Ag–In–Sb System at 200°C with Experimental Data

Summary. Binary thermodynamic data, successfully used for phase diagram calculations of binary systems Ag–In, Ag–Sb, and In–Sb, were used for prediction of phase equilibria in ternary Ag–In–Sb system at 200°C. Symmetrical Redlich–Kister–Muggianu model for ternary thermodynamic function calculation was proved to be best valid in this ternary system. Predicted equilibria were compared with experimentally (SEM, EDX) determined composition of phases in chosen alloys after long term annealing and with the results of DTA measurements.     

Comparison of Prediction of Phase Equilibria in the Ag–In–Sb System at 200°C with Experimental Data

Binary thermodynamic data, successfully used for phase diagram calculations of binary systems Ag–In, Ag–Sb, and In–Sb, were used for prediction of phase equilibria in ternary Ag–In–Sb system at 200°C. Symmetrical Redlich–Kister–Muggianu model for ternary thermodynamic function calculation was proved to be best valid in this ternary system. Predicted equilibria were compared with experimentally (SEM, EDX) determined composition of phases in chosen alloys after long term annealing and with the results of DTA measurements.     

Thermodynamic study of the eutectic Mg49–Zn51 alloy used for thermal energy storage

The eutectic Mg₄₉–Zn₅₁ (mass%) alloy has been identified as a suitable material for latent heat thermal energy storage. Within this scope, the exhibited solid–solid and solid–liquid phase transitions have been carefully characterized. A detailed thermodynamic study focused on the specific heat of the investigated alloy is also provided. The C _p behaviour, very important in the thermal energy storage frame, is theoretically modelled and experimentally validated by quasi-isothermal modulated differential scanning calorimetry measurements. Different intermetallic phases of the Mg–Zn binary system have also been successfully described within this approach in the complete temperature range.     

Contribution a l'etude du systeme ternaire aluminium-zinc-etain

This work is a study of theL?S andS?S equilibria in the ternary system Al-Zn-Sn. The diagram has been established by an isopleth cutting method using coupled direct and differential thermal analysis and an electron probe microanalyser. This study has permitted:

confirmation of the existence of invariant ternary reactions suggested in the literature;

demonstration of the existence, shape and limits of the SSα′ solid solution presenting tin retrograde solubility;

determination of the critical point temperature of the monovariant liquid curve conjugated toSSα andSSα′ solids (446?) rich in aluminium,