Ternary Aqueous Systems Research Articles

IUPAC-NIST Solubility Data Series. 100. Rare Earth Metal Fluorides in Water and Aqueous Systems. Part 3. Heavy Lanthanides (Gd–Lu)

This is the third part of the volume devoted to solubility data for the rare earth metal (REM) fluorides in water and in aqueous ternary and multicomponent systems. It covers experimental results of trivalent fluorides of Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu (so-called heavy lanthanides), since no quantitative data on solubilities of TbF4 and YbF2 (the most stable compounds at these valencies) are available. The related literature has been covered through the end of 2014. Compilations of all available papers with the solubility data are introduced for each REM fluoride with a corresponding critical evaluation. Every such assessment contains a collection of all solubility results in aqueous solution, a selection of suggested solubility data, a solubility equation, and a brief discussion of the multicomponent systems. Only simple fluorides (no complexes or double salts) are treated as the input substances in this report. General features of the systems, such as nature of the equilibrium solid phases, solubility as a function of temperature, influence of ionic strength, solution pH, mixed solvent medium on the solubility, quality of the solubility results, and the solubility as a function of REM atomic number, have already been presented in Part 1 of the volume.

Solid–liquid metastable phase equilibria for the ternary system (Li2SO4 + K2SO4 + H2O) at 288.15 and 323.15 K, p = 0.1 MPa

Metastable solubilities and physicochemical properties including density and refractive index of the aqueous ternary system (Li2SO4+K2SO4+H2O) at 288.15 and 323.15K and p=0.1MPa were determined with the isothermal evaporation method. On the basis of experimental data, the metastable phase diagrams and the diagram of physicochemical properties versus composition in the ternary system at 288.15 and 323.15K were plotted. In the metastable phase diagrams of this ternary system at 288.15 and 323.15K, in all there are two invariant points, three univariant solubility curves, and three metastable crystallization regions, corresponding to lithium sulfate monohydrate (Ls, Li2SO4·H2O), double salt (Db, K2SO4·Li2SO4) and arcanite (Ar, K2SO4). The hydrates in this system at both temperatures belong to a hydrate type I, and the double salt (K2SO4·Li2SO4) belongs to incongruent at 288.15K and congruent double salt at 308.15K, respectively. A comparison of the metastable phase diagrams at 288.15 and 323.15K shows that the area of Ar is decreased obviously whereas the areas of Db and Ls are increased with the increasing of temperature, and no solid solutions were found. The density and refractive index in the metastable ternary system at 288.15 and 323.15K change regularly with the mass fraction of potassium sulfate concentration and reach the extreme values at the invariant points. The densities and refractive indices were correlated with empirical equations, and the calculated values at two temperatures agree well with the experimental results.

High-pressure (vapour + liquid) equilibria for ternary systems composed by {(E)-2-hexenal or hexanal + carbon dioxide + water}: Partition coefficient measurement

A new apparatus based on a static–analytic method assembled in this work was utilised to perform high-pressure (vapour+liquid) equilibria measurements of aqueous ternary systems. This work includes values of isothermal partition coefficients between CO2 and water of two apple aroma constituents, (E)-2-hexenal and hexanal. Additionally, this work reports new experimental (vapour+liquid) equilibria measurements for the ternary systems (CO2+(E)-2-hexenal+water) and (CO2+hexanal+water), at fixed liquid phase composition (600mg·kg−1), at temperatures of (313, 323 and 333)K and at pressures from (8 to 19)MPa. Vapour liquid interphase was checked and monitored visually for all the systems studied in this work. No liquid immiscibility was observed at the composition, temperatures and pressures studied. In order to suggest reasonable operation conditions for fractionation of aromas with dense carbon dioxide, partition coefficients of the aroma compounds between CO2 and water along with their separation factors from water were calculated. Partition coefficients of (E)-2-hexenal between CO2 and water were in the range of (6 to 91) and where found to be near six times higher than those of hexanal (9 to 17). Very high separation factors from water were observed (∼104) especially for (E)-2-hexenal. The highest separation factor, for both compounds, was found at a temperature of 313K and pressures from (12 to 14)MPa.

Water activities of binary and ternary aqueous aluminium salts and poly(ethylene glycol) solutions at T = 303.15 K: Experimental and correlation

In this study, water activity measurements by isopiestic method have been carried out on some aqueous electrolyte solutions of both binary aqueous systems (Al(NO3)3, Al2(SO4)3 and AlCl3), ternary aqueous systems (polyethylene glycol+AlCl3+water) and (polyethylene glycol+Al(NO3)3+water) at T=303.15K. Furthermore, constant water activity curves, for ternary systems, have been plotted to study the salt effect. A relation between the salting-in effect of salt on the polymer aqueous solution and the slopes of constant water activity curves was reported. It was found that the slopes of constant water activity curves have a positive deviation from the linear isopiestic relation. In addition, the experimental water activity has been correlated successfully with some segment-based local composition models such as Wilson model, Non-Random Two Liquid (NRTL) model and the segment-based Non-Random Factor (NRF) model. The agreement between the correlation and the experimental data is good.

Phase equilibria in the ternary system (LiCl + Li2SO4 + H2O) at T = 308.15 K and p = 0.1 MPa: Experimental data and predictions using the Pitzer model

The solubilities and the physicochemical properties including density, viscosity, refractive index, conductivity, and pH of the aqueous ternary system (LiCl+Li2SO4+H2O) at T=308.15K and p=0.1MPa were determined using the isothermal evaporation method, and the metastable phase diagram and the physicochemical property diagram versus composition of liquid phase solution for the system at 308.15K were plotted. In the metastable phase diagram of the ternary system at 308.15K, there is one invariant point, two univariant curves, and three crystallization zones corresponding to lithium sulfate monohydrate (Li2SO4·H2O), lithium chloride monohydrate (LiCl·H2O) and (Li2SO4·H2O+LiCl·H2O). It belongs to the hydrate type I, and neither double salts nor solid solution were found. On the basis of Pitzer ion-interaction theory of the electrolytes and the chemical equilibrium HMW model, Pitzer single-salt parameter of lithium chloride at 308.15K was fitted, and the single-salt parameters of lithium sulfate, mixing ion-pair θCl,SO4, and the Debye–Hückel limiting slope AΦ at 308.15K were obtained according to the temperature-dependent equation of parameters presented in the literatures. And then, the solubilities on the ternary system (LiCl+Li2SO4+H2O) at 308.15K were calculated. A comparison shows that the calculated solubility agrees well with the experimental data.

IUPAC-NIST Solubility Data Series. 100. Rare Earth Metal Fluorides in Water and Aqueous Systems. Part 2. Light Lanthanides (Ce–Eu)

This is the second part of the volume devoted to the evaluation of experimental solubility data for rare earth metal (REM) fluorides in water as well as in aqueous ternary and multicomponent systems. Fluorides of Ce, Pr, Nd, Pm, Sm, and Eu (so-called light lanthanides), as the main solutes, are covered in the present part, which has thorough coverage of the experimental literature through the end of 2012. The experimentally unknown solubility value for PmF3 in water was predicted by an interpolation of the solubility values for NdF3 and SmF3 at 298 K. General features of the systems, such as the nature of the equilibrium solid phases, solubility as a function of temperature, influence of ionic strength, pH, mixed solvent medium on the solubility, quality of the solubility results, and solubility as a function of REM atomic number, have already been presented in Part 1 of the volume.

Draw solutions for Forward Osmosis process: Osmotic pressure of binary and ternary aqueous solutions of magnesium chloride, sodium chloride, sucrose and maltose

The objective of the present work is to investigate the behaviour of binary and ternary aqueous systems, which could be employed in the selection criteria for draw agents (DA) to be used in Forward Osmosis (FO) process applications. In this study the osmotic properties of the selected binary and ternary aqueous solutions of magnesium chloride (MgCl2), sodium chloride (NaCl), sucrose and maltose are investigated. Osmotic pressures were calculated from water activities obtained from measured relative humidity of the solutions of concentrations in the range 0.5–6.0molkg−1 at 298.15K. The osmotic behaviours of the ternary systems were compared with their binary counter parts; the results showed either positive or negative osmotic synergic effects. This could be used besides transport properties for considering the selection of favourable draw agents from those that exhibited positive synergy, i.e. the osmotic pressure of a ternary solution is greater than the sum of the pressures of the corresponding binary solutions. The results showed that the ternary aqueous solutions of MgCl2+NaCl showed significant positive synergy and therefore are possible suitable candidates as draw solutions, less so were the sugar–electrolyte systems.

Thermodynamics Phase Equilibria of the Aqueous Ternary Systems LiCl + KCl (MgCl2) + H2O at 348 K

The thermodynamics phase equilibria of the aqueous ternary systems LiCl + MgCl2 + H2O and LiCl + KCl + H2O at 348 K were investigated using an isothermal evaporation method. The solubilities and physicochemical properties such as density and refractive index of the equilibrated solution were determined. The compositions of solid phases were confirmed using the Scherinemakers’ wet residue method. In accordance with the experimental data, the phase diagrams and physicochemical vs composition diagrams were constructed. The ternary system LiCl + MgCl2 + H2O is of a complex type with double salt LiCl·MgCl2·7H2O (lithium carnallite) formed at 348 K, and its phase diagram consists of two invariant points, three univariant curves, and three crystallization fields corresponding to lithium chloride monohydrate (LiCl·H2O), magnesium chloride hexahydrate (MgCl2·6H2O), and lithium carnallite (LiCl·MgCl2·7H2O). The ternary system LiCl + KCl + H2O is of a simple eutectic type at 348 K, and its phase diagram is composed of one invariant point, two univariant curves and two crystallization fields corresponding to potassium chloride (KCl) and lithium chloride monohydrate (LiCl·H2O). Lithium chloride has a salting out effect on magnesium chloride or potassium chloride. Comparisons between the metastable and stable phase diagrams at 348 K of these two ternary systems have been drawn. In the system LiCl + MgCl2 + H2O, the crystallization region of MgCl2·6H2O under the metastable equilibrium is smaller, while the crystallization region of the LiCl·MgCl2·7H2O is larger. In the system LiCl + KCl + H2O, the crystallization regions of LiCl·H2O and KCl under metastable equilibrium are both smaller. Comparisons between the metastable phase diagrams of system LiCl + KCl + H2O at (298, 323, and 348) K show that the crystallization region of LiCl·H2O increased with the rise of temperature, whereas the crystallization region of salt KCl is decreased.

Equation for solvent activity correlation in ternary solutions with electrolyte and molecular components

An analytical thermodynamically self-consistent equation is proposed for the dependence on composition of the solvent activity of ternary solutions with electrolytic and molecular components (polyols, sugars, etc.). This equation was derived on the basis of the sum of contributions from short and long range interactions to the excess Gibbs free energy of solution. The correlation of experimental data corresponding to 20 aqueous ternary systems was successfully carried out. The results obtained demonstrate an excellent fitting capability of the proposed equation.

Solid-liquid Phase Equilibria in the Aqueous Ternary System Containing Lithium, Potassium, and Sulfate ions at 288.15 K

1 Introduction Salt lakes are widely distributed in the western of China,especially in the area of Qinghai-Xizang(Tibet)Plateau.A series of salt lakes in the Qaidam Basin,located in Qinghai Province,China,is famous for their abundance of lithium,potassium and boron resources(Zheng et al,1988;Deng et al,2012).It is well known that the

Prediction of solid–binder affinity in dry and aqueous systems: Work of adhesion approach vs. ideal tensile strength approach

Wet granulation process requires the addition of a coating agent or binder, typically composed of surfactants such as hydroxypropyl-methylcellulose (HPMC), water and a small amount of filler such as stearic acid (SA). In dry granulation however, the coating agent is added to the system in the form of fine solid particles. In both cases, a successful granulation requires good affinity between host and guest particles. In this study, we compare two approaches to predict the binder–substrate affinity in dry and in aqueous media, one based on the work of adhesion and the other based on the ideal tensile strength (Rowe, 1988). The novelties of this paper are four folds. First, the equations used in both approaches are generalized and rewritten as a function of the Hildebrand solubility parameter δ. δ is obtained from molecular simulations or predicted from HSPiP group contribution method. Secondly, a correlation between δ and the experimental surface tension γ is established for cellulose derivative (such as HPMC and ethyl cellulose). Thirdly, the concept of ideal tensile strength, originally formalized by Gardon (1967) for binary systems, is extended to ternary systems and applied for granulation in aqueous media. Fourthly, the approaches are tested for various systems and compared to experimental observations. For dry binary systems, predicted adhesive and cohesive properties agree with literature experimental observations, but the work of adhesion approach performs better than the ideal tensile strength approach. Both approaches predict that HPMC is a good binder for microcrystalline cellulose (MCC). The results also indicate that polyethylene glycol 400 (PEG400) has a good affinity with HPMC and stearic acid. For ternary aqueous systems, the results fully agree with the observations of Laboulfie et al. (2013).

Investigation of 1-(2-carboxyethyl)-3-methylimidazolium chloride[HOOCEMIM][Cl] ionic liquid effect on water activity and solubility of l-serine at T = 298.15 K

Water activity measurements by the isopiestic method have been carried out on the aqueous ternary system of {l-serine+1-(2-carboxyethyl)-3-methylimidazolium chloride[HOOCEMIM][Cl]} ionic liquid and the aqueous binary system of IL at T=298.15K and atmospheric pressure. The data obtained were used to calculate the vapor pressure and osmotic coefficient of solution as a function of concentration. The experimental results for the activity of water were accurately correlated with segment-based local composition models of modified NRTL and UNIQUAC. The fitting quality of the above models has been favorably compared with the NRTL and Wilson models. From these data, the corresponding activity coefficients have been calculated. For the same system, the solubility of the l-serine at various [HOOCEMIM][Cl] ionic liquid concentrations was measured at T=298.15K using the gravimetric method. A chemical model was employed to describe the dissociation equilibria of all amino acid species with hydrogen ions in water. Moreover, for l-serine, the chemical model indicated that the formation of cations is insignificant in the [HOOCEMIM][Cl] solution. Also the above local composition models were used to predict the solubility of l-serine in aqueous IL solutions. To provide information regarding (solute+solute) interactions, transfer Gibbs free energies (ΔGtr) of amino acid from water to aqueous IL solutions have been determined.

Investigation of amino acid-polymer aqueous biphasic systems.

Aiming at gathering further information to evaluate the recently proposed1,2 mechanism of the salt effect in aqueous polymer solutions, experimental vapor-liquid equilibria (VLE), liquid-liquid equilibria (LLE), and volumetric-compressibility measurements were carried out for several polymer-amino acid aqueous systems. The constant water activity lines (obtained through the isopiestic method at 298.15 K) of aqueous polypropylene glycol 400 (PPG400) + alanine or glycine systems, which form aqueous biphasic systems (salting-out effect), have a concave and convex slope, respectively, in the one-phase and two-phase regions. However, all the investigated polyethylene glycols (PEG400, PEG2000, PEG6000, and PEG10000) do not form aqueous biphasic systems with alanine or glycine (salting-in effect) and their constant water activity lines have a convex slope. In the second part of this work, the apparent molar volume and isentropic compressibility of transfer of alanine and glycine from water to aqueous solutions of PEG200, PEG2000, PEG10000, and PPG400 were studied at different temperatures. The third part of this work is concerned with the determination of LLE phase diagrams for several ternary polymer-amino acid aqueous systems containing polymers PPG400 and PPG725 and amino acids alanine, glycine, serine, and proline at different temperatures. On the basis of the obtained cloud point values of aqueous solutions of PPG725 in the absence and presence of various amino acids, it was found that all the investigated amino acids have a salting-out effect on PPG725 in aqueous solutions and entropy is the driving force for biphasic formation.

Mean activity coefficients measurement of sodium chloride and thermodynamic modeling of sodium chloride and polysodium acrylate aqueous mixtures at T = (298.2 and 303.2) K

In this work, thermodynamic properties of the ternary (sodium chloride+polysodium acrylate) aqueous system was investigated using the potentiometric method at T=(298.2 and 303.2)K. Potentiometric measurements were carried out on the galvanic cell with ion-selective electrodes containing a solvent polymeric (PVC) Na-ISE and Ag–AgCl over total molality from 0.0010 to 2.9997molkg−1 for various series of molal ratios (r=mNaCl/mNaPA=50, 40, 30, 20, and/or 15) and NaCl single electrolyte. Modeling of this ternary system was made based on proposed model and mixing interaction parameters (θClPA,ψNaClPA) were evaluated for the studied ternary system according to Pitzer graphical method. These parameters were used to calculate the values of the mean activity coefficients of NaPA, the osmotic coefficients, solvent activity and excess Gibbs free energies of the whole series for under investigation system.

Solid–liquid phase equilibria in the aqueous ternary system Li2SO4 + LiBO2 + H2O at T = 288.15 and 298.15 K

The solubility data and the physicochemical properties including density, pH value and refractive index of the ternary system Li2SO4+LiBO2+H2O at T=288.15 and 298.15K were determined experimentally with the isothermal dissolution equilibrium method. Based on the experimental results, the phase diagrams and their corresponding physicochemical properties versus composition diagram in the system were plotted. The phase diagrams for the system at T=288.15 and 298.15K are all in one invariant point for (Li2SO4·H2O+LiBO2·8H2O), two univariant curves, and two crystallizing regions corresponding to the lithium sulfate monohydrate (Li2SO4·H2O) and lithium metaborate octahydrate (LiBO2·8H2O). The phase diagrams of the ternary system at two temperatures belong to hydrate type I, and neither double salt nor solid solution was found. A comparison of the phase diagrams for the ternary system at 298.15 and 288.15K shows that the crystallized area of Li2SO4·H2O is increased with the increasing of temperature while that of LiBO2·8H2O is decreased obviously. The physicochemical properties (density, pH value and refractive index) in the ternary system at 288.15 and 298.15K are changed regularly with the increasing of lithium sulfate concentration in the solution, and singular phenomena for the extreme values are amazedly appeared at the invariant points.

IUPAC-NIST Solubility Data Series. 100. Rare Earth Metal Fluorides in Water and Aqueous Systems. Part 1. Scandium Group (Sc, Y, La)

This work presents an assessment of solubility data for rare earth metal fluorides (generally of trivalent metals and of CeF4) in water and in aqueous ternary systems. Compilations of all available experimental data are introduced for each rare earth metal fluoride with a corresponding critical evaluation. Every such evaluation contains a collection of all solubility results in water, a selection of suggested solubility data, and a brief discussion of the multicomponent systems. Because the ternary systems were seldom studied more than once, no critical evaluations of such data were possible. Only simple fluorides (no complexes or binary salts) are treated as the input substances in this report. The literature has been covered through the end of 2013.

1:1 and 1:2 Inclusion Complexes of Di-tert-butyl l-tartrate with α-Cyclodextrin: A Diffusion Study

The diffusion properties at two overall compositions of a ternary aqueous system containing α-cyclodextrin and a double-functional guest molecule, namely di-tert-butyl l-tartrate, have been studied by means of the Gouy interferometry. The experimental data are interpreted in terms of two independent chemical equilibria involving inclusion compounds. The elements of the diffusion coefficient matrix have been expressed as functions of the two equilibrium constants as well as of the diffusivities of the actual species occurring in solution. The reliability of the diffusion coefficients obtained through the Fujita–Gosting–Revzin procedure is also discussed in terms of its dependence on the composition of solutions used in the Gouy experiments.

Experimental data and thermodynamic modeling of ternary aqueous biphasic systems of EO/PO polymers–Na2SO4–H2O

Liquid–liquid extraction using thermoresponsive polymers as solvents in aqueous two phase systems followed by induced phase separation to recover the polymers is a potential technology for water–salt separations. Here we report for seven polymers on their ternary systems containing water, sodium sulfate and the (block co)poly ether. Equilibrium data were measured at 298.15K and 313.15K and atmospheric pressure. Empirical equations have been used to correlate the experimental equilibria for both temperatures separately and the semi-empirical NRTL model has been applied with a temperature dependent parameter to describe the complete dataset for both temperatures together. Model predictions were in good agreement with the experimental data.

ChemInform Abstract: IUPAC‐NIST Solubility Data Series. 94. Rare Earth Metal Iodides and Bromides in Water and Aqueous Systems. Part 1. Iodides

AbstractReview: 105 refs.

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.