Solubility Of Ternary System Research Articles

How can we improve the physical stability of co-amorphous system containing flutamide and bicalutamide? The case of ternary amorphous solid dispersions

The article describes the preparation and characterization of binary mixtures of two antiandrogens used in prostate cancer treatment, i.e. flutamide (FL) and bicalutamide (BIC), as well as their ternary mixtures with either poly(methyl methacrylate-co-ethyl acrylate) (MMA/EA) or polyvinylpyrrolidone (PVP). The samples were converted into amorphous form to improve their water solubility and dissolution rate. Broadband dielectric spectroscopy and differential scanning calorimetry revealed that FL-BIC (65%) (w/w) does not tend to crystallize from the supercooled liquid state. We made the assumption that the drug-to-drug weight ratio should be maintained as in the case of monotherapy so we decided to investigate the system containing FL and BIC in 15:1 (w/w) ratio with 30% additive of polymers as stabilizers. Our research has shown that only in the case of the FL-BIC-PVP mixture the crystallization has been completely inhibited, both in glassy and supercooled liquid state, which was confirmed by X-ray diffraction studies. In addition, we performed solubility and dissolution rate tests, which showed a significant improvement in solubility of ternary system as compared to its crystalline counterpart. Enhanced physical stability and water solubility of the amorphous ternary system makes it promising for further studies.

Thermodynamic properties in ternary system of NH4HCO3–H2O–ethanol based on antisolvent method to strengthen crystallization of carbonized ammonia

One of the main challenges of the ammonia-based CO2 capture process is how to further reduce the regeneration energy consumption. An antisolvent crystallization method was proposed to strengthen the crystallization process of carbonized ammonia, and heating the crystal products instead of rich solution can greatly reduce renewable energy consumption. The main component of the crystal product was NH4HCO3 analyzed by X-ray diffraction. Therefore, it is very important to study the thermodynamic properties of ammonium bicarbonate in the ternary system of NH3–H2O–ethanol. In this paper, the solubility curves under different temperature and solvent compositions were determined by static method and the mathematical model of solubility was established. The effects of the addition of ammonium carbamate which was produced in the initial stage of the CO2 absorption process and the addition of ammonia on the solubility in ternary system of NH4HCO3–H2O–ethanol were studied. The dissolution heat was also calculated in the end. The research of this article has a guiding significance for the antisolvent method to strengthen the crystallization of carbonized ammonia of ammonia-based carbon capture technology. It is helpful to further strengthen the crystallization process of low carbonized ammonia and improve the crystallization yield.

Solubility of cinnamic acid in supercritical carbon dioxide and subcritical 1,1,1,2-tetrafluoroethane: Experimental data and modelling

To promote the extraction of natural cinnamic acid with supercritical and subcritical fluids, the solubility of cinnamic acid was measured respectively in supercritical carbon dioxide (SCCO2) by the dynamic method and in subcritical 1,1,1,2-tetrafluoroethane (sub-R134a) by the static method. The experiments were performed at temperatures from 308 K to 328 K and pressures of 9.0, 11.0, 13.0, 15.0, and 18.0 MPa. The solubility of cinnamic acid in SCCO2 and sub-R134a were compared by calculating the enhancement factor (δ), which indicated that the value of δ in sub-R134a is greater than that in SCCO2; meanwhile, the entrainment factor (ψ), which describes the influence of co-solvent (ethanol, ethyl acetate and n-pentane) on the cinnamic acid solubility in SCCO2, showed that the solubility of cinnamic acid in SCCO2 increased with the co-solvent polarity increasing. Six semi-empirical models (Chrastil, A-L, K-J, S-S, M-S-T, and Bartle) were used to correlate cinnamic acid solubility in binary system (cinnamic acid + SCCO2 or sub-R134a) and four models (Gonzalea, Sovova, Tang and Sauceau) were used to correlate cinnamic acid solubility in ternary system (cinnamic acid + SCCO2+co-solvent). The enthalpy values of cinnamic acid, including ΔHtotal, ΔHsub. and ΔHsol., were estimated through Chrastil and Bartle models; and the partial molar volume of cinnamic acid was calculated by K-J model. A new model was proposed on the basis of the molecular association theory and verified by 47 solid solutes solubility in SCCO2 or sub-R134a with satisfactory correlation results.

Solubility in the ternary system fullerenol-d-uranyl sulfate-water at 25°C

The solubility in ternary systems fullerenol-d-UO2SO4-H2O at 25°C was studied by the method of isothermal saturation in ampules. The diagram consists of two branches corresponding to crystallization of fullerenol-d crystal hydrate and uranyl sulfate trihydrate and contains one nonvariant point of eutonic type, corresponding to joint saturation with both crystal hydrates. The eutonic is very close to the figurative point corresponding to the binary system UO2SO4-H2O at 25°C. Strongly pronounced salting-out effect is observed in the crystallization branch of fullerenol-d crystal hydrate.

Application of the perturbed chain-SAFT equation of state for modeling CO2 solubility in aqueous monoethanolamine solutions

CO2 removal by treatment of acid gases by aqueous alkanolamines is a very significant operation from industrial and environmental point of view. To attain a comprehensive thermodynamic model of the CO2–MEA–H2O in a wide range of temperature and CO2 partial pressures, Perturbed Chain-Statistical Associating Fluid Theory (PC-SAFT) EOS is applied to predict the absorption of carbon dioxide by MEA (MonoEthanolAmine). In order to find the best association scheme for MEA in PC-SAFT EOS, three pure parameter sets for MEA in the 2B, 3B and 4C association schemes are determined in temperature range 303.15–443.15K. Temperature independent binary interaction parameters have been adjusted in the VLE calculation for three schemes of MEA and two schemes of water. Binary VLE calculations show the 3B scheme for MEA and the 4C scheme for water indicate the best prediction in the MEA–H2O system. Excess enthalpy data for aqueous MEA are predicted by kij, which has been adjusted in VLE calculations. The 3B scheme for MEA and the 4C scheme for water also are used to find CO2 solubility in the ternary system of CO2–MEA–H2O system. Ideal Smith–Missen algorithm has been applied to find the concentration of all species in chemical equilibrium. Results show the 3B association scheme for MEA and the 4C association scheme for water in PC-SAFT EOS have better agreement with binary and ternary experimental data. PC-SAFT EOS is able to anticipate the CO2 solubility in the CO2–MEA–H2O system without any regression in the ternary system. The CO2 solubility in ternary system is compared to e-NRTL as a common thermodynamics model. The average absolute partial pressure deviations for PC-SAFT and e-NRTL are calculated around 36% and 42%, respectively.

Solubilities of benzene sulfonamide in supercritical CO 2 in the absence and presence of cosolvent

Solubilities of benzene sulfonamide in supercritical CO 2 were measured by using dynamic method at temperature ranging from 308.15 to 328.15 K over a pressure range of 11.0–21.0 MPa. The experimental data in binary system were correlated with eight semi-empirical equations. The calculated result shows that the equation proposed by Adachi and Lu (A–L) provides the best correlation to the experimental data. The AARD (%) for A–L equation is 5.53. The thermodynamic properties (total enthalpy Δ H, sublimation enthalpy Δ H sub. and solvation enthalpy Δ H solv.) of solid solute were obtained. The cosolvent investigated in this work was ethanol, ethylene glycol and ethyl acetate, respectively. The solubilities in ternary system were determined with molar fraction of 3.5% (cosolvent) at 308.15 K over a pressure range of 11.0–21.0 MPa. The enhancement factor of each cosolvent was calculated. The experimental data in ternary system were correlated by using T–G equation and modified Sovova equation.

Thermodynamics of arsenates, selenites, and sulfates in the oxidation zone of sulfide ores. II. Systems M1, M2//SO 4 2− -H2O (M1, M2 = Fe2+, Fe3+, Cu2+, Zn2+, Pb2+, Ni2+, Co2+, H+) at 25°C

High toxicity of arsenic and selenium makes it important to analyze conditions, under which sulfates, arsenates, and selenites replace sulfides, arsenides, and selenides in the oxidation zones of sulfide ore deposits and in weathered technogenic waste. Published experimental data have been summarized for solubility in ternary systems containing Fe, Cu, Zn, Pb, Ni, and Co sulfates. Due to high solubility of solid phases, the thermodynamic description of solutions was carried out using the Pitzer equations; the necessary parameters were found in the literature or calculated in this article. The applied model was preliminarily verified by experimentally obtained diagrams of solubility. A database was compiled for quantitative thermodynamic modeling of mineral equilibria in most ternary and four-component subsystems of the Fe2+, Cu2+, Zn2+, Ni2+, Co2+//SO42−-H2O system. The lack of experimental data for the systems containing Fe(III) sulfate does not allow calculating necessary parameters of its interaction with other sulfates and conducting calculations in multicomponent systems without simplifications and additional assumptions. Solubility diagrams are considered for the following systems: FeSO4-H2SO4-H2O, NiSO4-H2SO4-H2O, CuSO4-H2SO4-H2O, ZnSO4-H2SO4-H2O, CoSO4-H2SO4-H2O, FeSO4-Fe2(SO4)3-H2O, CoSO4-NiSO4-H2O, ZnSO4NiSO4-H2O, FeSO4-CoSO4-H2O, FeSO4-NiSO4-H2O, FeSO4-CuSO4-H2O, CoSO4-CuSO4-H2O, NiSO4-CuSO4-H2O, and ZnSO4-CoSO4-H2O. For some of these systems, equilibrium phase diagrams are calculated in this article.

Solubility in the ternary system LiCl + MgCl2 + H2O at 60 and 75°C

The solubility of ternary system of lithium, magnesium and chloride and refractive indexes have been determined at 60 and 75°C, respectively. Using the experimental results, the phase diagrams of the ternary system were plotted. The single-salt Pitzer parameters of LiCl and MgCl2 β(0), β(1) and Cϕ were calculated by using the equations reported by Li Y-H and de Lima at different temperatures, respectively. On the basis of Pitzer ion-interaction model and solubility product equation for mixed electrolytes, the mixing parameters θLi, Mg, ΨLi, Mg, Cl and equilibrium constant Ksp were evaluated in this system, which were not reported in literature. A complete phase diagram of the ternary system was predicted at 60 and 75°C. The prediction of solubilities in ternary system was then demonstrated. The calculated solubilities agreed well with the experimental values.

Thermodynamic assessment of Al–Cu–Dy system

Phase equilibria of ternary Al–Cu–Dy system has been analyzed and a complete thermodynamic description was obtained. The thermodynamic descriptions of its three constituent binary systems were taken from literature. Most of the binary intermetallic phases, except Al 2Dy, Cu 2Dy, and CuDy, were treated to have zero solubility in ternary system. Based on experimental data, seven stable ternary intermetallic phases were taken into consideration in this system. Among them, three were treated as semistoichiometric compounds with large homogeneity ranges for Al and Cu. The rest were treated as stoichiometric compounds. The calculated phase equilibria were in agreement with available experimental data.

Hydration Analysis and the Expansion of Relative Activity Coefficients

Of correlation methods for solubility in ternary systems, the method of expansion of relative activity coefficients and the hydration analysis are based on the thermodynamic condition of phase equilibria. Both of them require only reliable solubility data in the ternary system and corresponding binary systems. Correlation parameters of both of these methods are interrelated and the methods are compared on the system K2SO4-H2SO4-H2O at 50 °C.

Fluid phase equilibria of binary and ternary mixtures of supercritical carbon dioxide with a 1-alkanol and an n-alkane up to 100 MPa and 393 K—cosolvency effect and miscibility windows (Part II)

Cosolvency effects and miscibility windows were studied in selected ternary systems containing a supercritical solvent (CO 2), a 1-alkanol (1-nonanol to 1-undecanol) and an n-alkane as the third component ( n-pentadecane to n-octadecane) according to the analytical method. In the present experiments the ranges of temperature and pressure were 288 K to 393 K and 7.5 MPa to 100 MPa respectively. A new technique (so-called quasi-synthetic method) is described to determine critical parameters of binary mixtures from synthetic measurements performed with the gaseous component being the pressurizing medium. It is the aim of the present investigations to give a quantitative description of the cosolvency effect as a function of temperature and of the chain lengths of the 1-alkanol and the n-alkane respectively, as a continuation of the systematic investigations of Kordikowski and Schneider (1993) as well as of Pöhler and Schneider (1995). In order to compare systems with or without a pressure minimum on the ternary critical line at a constant temperature, a mean cosolvency effect was introduced, being a measure for improved solubility in ternary systems which expresses itself by a positive curvature of the ternary critical line at constant temperature.