Measurement of solubility of erythromycin acetone solvate in aqueous acetone solution between 298 K and 323 K

Using a laser monitoring observation technique, the solubility of erythromycin acetone solvate in binary acetone + water solvent mixtures was measured by a synthetic method at temperatures ranging from 298.00 K to 323.00 K and at atmosphere pressure. The results of these measurements were correlated by the combined nearly ideal binary solvent CNIBS/Redlich–Kister equation and the modified Apelblat equation, respectively. For the solubility data studied, the CNIBS/Redlich–Kister equation was found to provide a more accurate mathematical representation of the experimental data.     

Measurement and Correlation Solubility of Sodium Succinate in Binary Mixed Solvents of Water + (Methanol or Ethanol) Mixtures

The solubility of sodium succinate in binary solvent mixtures was measured by an analytical stirred-flask method in the temperature range 278.15–318.15 K at atmospheric pressure. It was found that the solubility of sodium succinate in the system increased with increasing temperature and decreased with the increasing mass fractions of methanol or ethanol. The modified Apelblat equation, the Buchwski–Ksiazaczak λh equation and the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) equation were proposed for correlating the experimental data. The modified Apelblat equation was found to regress the solubility data much better than the Buchwski–Ksiazaczak equation and the CNIBS/R–K equation in a binary solvent system. The dissolution enthalpy and dissolution entropy of sodium succinate were calculated from the solubility data, using the Van’t Hoff equation. The experiment results and correlation models could be used as essential data in the purification of sodium succinate.     

Thermodynamic models for determination of the solubility of dibenzothiophene in (methanol + acetonitrile) binary solvent mixtures

In this paper, we focused on solubility and solution thermodynamics of dibenzothiophene. By the gravimetric method, the solubility of dibenzothiophene was measured in (methanol + acetonitrile) binary solvent mixtures at temperatures from (278.15 to 333.15) K under atmosphere pressure. The solubility data were fitted using a modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redich–Kister (CNIBS/R–K) model and Jouyban–Acree model. Computational results showed that the modified Apelblat equation was superior to the other two equations. In addition, the thermodynamic properties of the solution process, including the Gibbs free energy, enthalpy, and entropy, were calculated by the van’t Hoff analysis. The experimental results showed that methanol could be used as effective anti-solvents in the crystallization process.     

Volumetric properties of the water + 3-(dimethylamino) propylamine (DMAPA) mixture at atmospheric pressure from 283.15 to 353.15 K

Densities of the water + 3-(dimethylamino) propylamine (DMAPA) binary system were measured at atmospheric pressure over the whole range of compositions at temperatures from 283.15 to 353.15 K using Anton Paar digital vibrating glass tube densimeter. The density of this system has been found an increasing function of water composition and a decreasing function of temperature. Excess molar volumes have been correlated using Redlich-Kister equations. Sets of parameters have been determined from experimental data to obtain correlations in the measurement range uncertainty. Partial molar volumes on the whole concentration range have been determined using Redlich-Kister parameters.     

Solid–liquid phase equilibrium and mixing thermodynamic analysis of coumarin in binary solvent mixtures

The solubility of coumarin in three aqueous solvent mixtures (methanol + water, ethanol + water and acetone + water) was experimentally determined by a gravimetric method at atmospheric pressure. The experimental solubility data were fitted using the modified Apelblat equation, non-random two-liquid (NRTL) equation, the combined nearly ideal binary solvent/Redlich–Kister equation and the Jouyban?Acree equation, respectively. All the equations were proven to be able to correlate the experimental data, and the modified Apelblat equation could obtain better correlation results than the other three models. The solubility of coumarin increases with increase in temperature. At the same temperature, the solubility increases with increase in mole fraction of organic solvents except for the ethanol–water system which shows a unimodal curve. In addition, the apparent thermodynamic properties of the mixing process were calculated based on the NRTL model and the experimental solubility data.     

Volumetric properties of the water + ethylenediamine mixture at atmospheric pressure from 288.15 to 353.15 K

Densities of the water + ethylenediamine binary system were measured at atmospheric pressure over the whole range of compositions at temperatures from 288.15 to 353.15 K using an Anton Paar digital vibrating glass tube densimeter. Density increases with water content. The experimental excess molar volume data have been correlated with the Redlich-Kister equation, and partial molar volumes calculated at infinite dilution for each component.     

Solubility, Dissolution Enthalpy and Entropy of Isoimperatorin in Ethanol?+?Water Solvent Systems from 288.2 to 328.2?K

The solubility of isoimperatorin in pure solvents and solvent mixtures was measured by UV spectrophotometry from 288.2 to 328.2?K. The solubility of isoimperatorin in binary ethanol and water solvent systems increases with temperature and with decrease of the mole fraction of water in the solvent mixture. The solubility data were correlated with a modified Apelblat equation. The enthalpy and entropy of dissolution of isoimperatorin were evaluated using the van??t Hoff equation.     

Determination and Correlation of the Solubility of Acetylpyrazine in Pure Solvents and Binary Solvent Mixtures

The solubilities of acetylpyrazine in seven pure solvents and one binary solvent mixture were determined by a dynamic analytic method at temperatures ranging from 268.15 to 308.15 K under atmospheric pressure. For pure solvents, the solubility of acetylpyrazine increases with increasing temperature and solvent polarity. For the binary solvent mixture of ethyl acetate and isopropanol, the solubility increases with increasing temperature and mole fraction of ethyl acetate. The solubility data were correlated with some thermodynamic models, including the modified Apelblat model, λh model, CNIBS/R-K model, and NRTL model. In addition, the relationship between solubility and solvent polarity was investigated by using the Arrhenius equation. All the models or equations gave satisfactory correlation results. The results showed that the solubility of acetylpyrazine generally rises with the increase of solvent polarity at the same temperature. Moreover, the dissolution thermodynamic properties of acetylpyrazine in different solvents were calculated and are discussed based on the NRTL model.     

Excess molar enthalpies and heat capacities of dimethyl sulfoxide + seven normal alkanols at 303.15 K and atmospheric pressure

Excess molar enthalpies and heat capacities of binary mixtures containing dimethyl sulfoxide (DMSO) + seven normal alkanols, namely methanol, ethanol, propan-1-ol, butan-1-ol, hexan-1-ol, octan-1-ol, and decan-1-ol, have been determined at 303.15 K and atmospheric pressure. With the exception of the DMSO-methanol system, which shows negative values, all mixtures show positive values of excess molar enthalpies over the whole range of mole fraction, increasing as the number of carbon atoms increases. Heat capacities of pure components have been determined in the range 288.15 < T (K) < 325.15. Molar heat capacities of the mixtures are always positive and decrease as the number of carbon atoms decreases. The results were fitted to the Redlich-Kister polynomial equation. Molecular interactions in the mixtures are interpreted on the basis of the results obtained.     

Density, dynamic viscosity, and derived properties of binary mixtures of methanol or ethanol with water, ethyl acetate, and methyl acetate at T = (293.15, 298.15, and 303.15) K

Densities and dynamic viscosities for methanol or ethanol with water, ethyl acetate, and methyl acetate at several temperatures T = (293.15, 298.15, and 303.15) K have been measured over the whole composition range and 0.1 MPa, along with the properties of the pure components. Excess molar volumes, viscosity deviations, and excess free energy of activation for the binary systems at the above-mentioned temperatures, were calculated and fitted to the Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. UNIQUAC equation was used to correlate the experimental viscosity data. The UNIFAC-VISCO method and ASOG-VISCO method, based on contribution groups, were used to predict the dynamic viscosities of the binary mixtures.     

Solubilities of oleanolic acid and ursolic acid in (ethanol + water) mixed solvents from T = (292.2 to 328.2) K

The solubility of oleanolic acid and of ursolic acid in (ethanol + water) mixed solvents was measured over the temperature range of (292.2 to 328.2) K. The solubility of oleanolic acid and of ursolic acid in the (ethanol + water) mixed solvent systems increase with increasing the mole fraction of ethanol in mixed solvents. The experimental solubility data are correlated by a simplified thermodynamic equation and the modified Apelblat equation.     

Solubility and solution thermodynamics of 2,3,4,5-tetrabromothiophene in (ethanol + tetrahydrofuran) binary solvent mixtures

The solubility of 2,3,4,5-tetrabromothiophene in (ethanol + tetrahydrofuran) binary solvent mixtures was measured within the temperature range from (278.15 to 322.15) K. The solubility increases with the rise of temperature, while it decreases with increasing ethanol content at constant temperature. The experimental data were fitted using the two variants of the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) equation and the Jouyban–Acree equation, respectively. All the three equations were proven to give good representations of the experimental values. Computational results showed that the variant two of CNIBS/R–K equation was superior to the other two equations. The thermodynamic properties of the solution process, including the Gibbs free energy, enthalpy, and entropy, were calculated by the van’t Hoff analysis. The values of both the enthalpy change and the standard molar Gibbs free energy change of solution were positive, which indicated that the process was endothermic.     

Study of equilibrium solution and thermodynamic models in correlation with solubility data of rivastigmine tartrate in (H2O + isopropanol), (H2O + ethanol), and (H2O + acetonitrile) binary solvent mixtures

Millions of people around the world have been suffering from Alzheimer’s disease (AD) everyday. Rivastigmine tartrate is a potential AD drug. A crystallization process can enhance purities of rivastigmine tartrate properly. Predictive models for solubilities of rivastigmine tartrate will improve subsequent industrial crystallization process design. In this work, the solubility of rivastigmine tartrate in (H₂O?+?isopropanol), (H₂O?+?ethanol), and (H₂O?+?acetonitrile) binary solvent systems in the temperature range of 278.15–333.15 K under atmospheric pressure was measured and investigated by employing the analytical stirred-flask method. Binary solvent systems of rivastigmine tartrate overcame drawbacks of mono-solvent crystallization systems, such as high viscosity. Three thermodynamic models, including modified Apelblat equation, the general cosolvency model, and the Jouyban–Acree model, were employed to correlate with the obtained experimental solubility data. Moreover, the calculations of apparent thermodynamic properties of rivastigmine tartrate dissolution process involving the Gibbs free energy, enthalpy, and entropy were accomplished by using the van’t Hoff analysis. Among the three models, the modified Apelblat equation is the most suitable one for predicting the solubility behavior of rivastigmine tartrate in binary solvent systems. Based on the data from modified Apelblat equation, a crystallization process of (H₂O?+?ethanol) binary solvent mixture was developed.

     

Solubility of Succinic Acid in Ethanol Plus Water Systems from 278.15 K to 333.15 K

In an equilibrium vessel, the solubilities of succinic acid in binary aqueous ethanol solvents were measured by the analytical stirred-flask method with the temperature ranging from 278.15 to 333.15 K at atmospheric pressure. Data on the corresponding solid–liquid equilibrium of succinic acid in binary aqueous ethanol solutions are essential for industrial design and further theoretical studies. The effect of solvent composition and temperature on the solubility is discussed. The solubility data were correlated with the Combined Nearly Ideal Binary Solvent/Redlich-Kister (CNIBS/R-K) model. The solubility measured in this study can be used for succinic acid purification or optical resolution by the preferential crystallization procedure.     

Isobaric vapor–liquid equilibria for the quaternary reactive system: Ethanol + water + ethyl lactate + lactic acid at 101.33 kPa

Isobaric vapor–liquid equilibrium (VLE) data of the reactive quaternary system ethanol (1) + water (2) + ethyl lactate (3) + lactic acid (4) have been determined experimentally. Additionally, the reaction equilibrium constant was calculated for each VLE experimental data. The experimental VLE data were correlated using the UNIQUAC equation to describe the chemical and phase equilibria simultaneously. For some of the non-reactive binary systems, UNIQUAC binary interaction parameters were obtained from the literature. The rest of the binary UNIQUAC parameters were obtained by correlating the experimental quaternary VLE data obtained in this work. A maximum pressure azeotrope at high water concentration for the binary reactive system ethyl lactate + water has been calculated.     

Measurement and correlation of vapor–liquid equilibria for methanol + methyl laurate and methanol + methyl myristate systems near critical temperature of methanol

A flow-type method was adopted to measure the vapor–liquid equilibria for methanol + methyl laurate and methanol + methyl myristate systems at 493–543 K, near the critical temperature of methanol (T_c = 512.64 K), and 2.16–8.49 MPa. The effect of temperature and fatty acid methyl esters to the phase behavior was discussed. The mole fractions of methanol in liquid phase are almost the same for both systems. In vapor phase, the mole fractions of methanol are very close to unity at all temperatures. The present vapor–liquid equilibrium data were correlated by PRASOG. A binary parameter was introduced to the combining rule of size parameter. The binary parameters of methanol + fatty acid methyl ester systems were determined by fitting the present experimental data. The correlated results are in good agreement with the experimental data. The vapor–liquid equilibria for methanol + methyl laurate + glycerol and methanol + methyl myristate + glycerol ternary systems were also predicted using the methanol + fatty acid methyl ester binary parameters. The mole fractions of methanol in vapor phase are around unity even if glycerol is included in the systems.     

Molar heat capacities for (1-butanol + 1,4-butanediol, 2,3-butanediol, 1,2-butanediol, and 2-methyl-2,4-pentanediol) as function of temperature

The isobaric molar heat capacities for the binary mixtures (1-butanol + 1,4-butanediol) were determined in the temperature range from (293 to 353) K from measurements of isobaric specific heat capacity in a differential scanning calorimeter. The composition dependencies of the excess molar isobaric heat capacities obtained from the experimental results were fitted by the Redlich-Kister polynomials. Above T = 303.15 K, the excess isobaric molar heat capacities are negative over the whole composition range and absolute values increase with temperature. For temperatures (293.15 and 298.15) K, the excess values show S-shaped character. These excesses are however in general very small; at the temperature 298.15 K smaller than 0.1 J · K⁻¹ · mol⁻¹.Additionally, the isobaric molar heat capacities of 2,3-butanediol, 1,2-butanediol, and 2-methyl-2,4-pentanediol were determined over a similar temperature range. The experimental data for all diols are compared with available literature data and values estimated from group additivity.     

Solubility of Atrazine in Binary Mixtures of Water + Ethanol or 1-Propanol from 283.15 to 343.15 K

The solubility of atrazine (solid) was measured in water + ethanol and water + propanol from 283.15 to 343.15 K. The experimental results showed that in ethanol + water and 1-propanol + water the solubility of atrazine increased slowly with temperature below 308.15 K but increased significantly above 308.15 K. It was also found that the slope of the solubility–temperature curve increases significantly with an increase in the mole fraction of organic solvent in the mixtures. The modified Apelblat and NRTL equations were applied to describe the measured systems. The model parameters of the NRTL equation were expressed as a function of temperature.     

Vapor-liquid equilibria at 333.15 K and excess molar volumes and deviations in molar refractivity at 298.15 K for mixtures of diisopropyl ether, ethanol and ionic liquids

In this work, we have studied influence of ionic liquids (ILs) on the azeotrope composition for the system {diisopropyl ether (DIPE) + ethanol} using trihexyltetradecylphosphonium chloride ([P_666,14][Cl]) and trihexyltetradecylphosphonium bis(2,2,4-trimethylpentyl) phosphinate ([P_666,14][TMPP]). Isothermal vapor-liquid equilibrium data at 333.15 K are reported for the ternary systems {DIPE + ethanol + [P_666,14][Cl]} and {DIPE + ethanol + [P_666,14][TMPP]} with varying the mole fraction of ILs from 0.05 to 0.10. The experimental ternary VLE data were correlated using the Wilson equation. In addition, excess molar volumes (V^E) and deviations in molar refractivity (ΔR) data at 298.15 K are reported for the binary systems {DIPE + [P_666,14][Cl]} and {ethanol + [P_666,14][Cl]} by a digital vibrating tube densimeter and a precision digital refractometer. The V^E and ΔR were correlated by the Redlich-Kister equation.