Solubility measurement and modelling of 1,8-dinitronaphthalene in nine organic solvents from T = (273.15 to 308.15) K and mixing properties of solutions

The solubility of 1,8-dinitronaphthalene in acetonitrile, methanol, ethanol, trichloromethane, isopropanol, acetone, toluene, ethyl acetate and butyl alcohol were obtained experimentally at temperatures ranging from (273.15 to 308.15) K under 0.1 MPa by using a gravimetric method. The solubility of 1,8-dinitronaphthalene in those solvents increases with an increase in temperature. The solubility values decrease according to the following order: acetone > (acetonitrile, ethyl acetate) > trichloromethane > toluene > methanol > ethanol > isopropanol > butyl alcohol. Three models, the modified Apelblat equation, Wilson and NRTL were used to correlate the solubility of 1,8-dinitronaphthalene in the solvents studied. The calculated solubility by the modified Apelblat equation provides better agreement than those evaluated by the other two models. The regressed results via the three models are all acceptable for the solubility of 1,8-dinitronaphthalene in the selected solvents. Furthermore, the mixing Gibbs energy, mixing enthalpy, and mixing entropy for per 1 mol of mixture of 1,8-dinitronaphthalene and solvents were calculated based on the Wilson model. The dissolution process of 1,8-dinitronaphthalene in the selected solvents is spontaneous and exothermic.     

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 of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven.     

Solubility of tridecanedioic acid in pure solvent systems: An experimental and computational study

Solubility has been extensively investigated by the phase equilibria approach at the mesoscale level, but its origin on the molecular and electronic levels is poorly understood. This study explored the solubility behaviour of crystalline solid in selected pure solvents with various functional groups by using both phase equilibria and molecular modelling methods. The model compound tridecanedioic acid (TDDA) solubility in methanol, ethanol, acetic acid, acetone, and ethyl acetate was determined from T = (283.15 to 323.15) K by a static method. It was found that almost all solutions studied exhibit non-ideal behaviour and deviate positively from Raoult’s law indicating the important role of homo-molecules interactions. Thermodynamic analyses of solution suggest that both enthalpy and entropy of solution govern the dissolution process. Computational studies on solubility behaviour were performed by using both density functional theory (DFT) calculations and molecular dynamic (MD) simulations. The results conclude that the (solute + solvent) interaction is not the only factor determining solubility, and (solvent + solvent) interaction also plays an important role. The simulated results are found to be qualitatively consistent with experimental values. Finally, solubility values were correlated by the empirically modified Apelblat equation and two local composition models of Wilson and NRTL.     

Determination and correlation of solubility of tylosin tartrate in alcohol mixtures

Data on (solid + liquid) equilibrium of tylosin tartrate in {methanol + (ethanol, 1-propanol or 2-propanol)} solvents will provide essential support for industrial design and further theoretical studies. In this study, the solubility of tylosin tartrate in alcohol mixtures was measured over temperature range from (278.15 to 323.15) K under atmospheric pressure by a gravimetric method. From the experimental results, the solubility of tylosin tartrate in selected solvents noted above was found to increase with increasing temperature and mass fraction of methanol. The solubility data were correlated with the modified Apelblat equation, the λh equation and van’t Hoff equation. The results showed that the three equations agreed well with the experimental values, and that the modified Apelblat equation was more accurate than the λh equation and van’t Hoff equation. Further, the standard enthalpy, standard entropy and standard Gibbs free energy of solution of tylosin tartrate in mixed solvents were calculated according to solubility results, model parameters with modified Apelblat equation and van’t Hoff equation.     

Solubility of diosgenin in different solvents

The solubility of diosgenin in methanol, ethanol (95%), isopropanol, acetone, acetic ether, and propyl acetate were measured at temperatures from (295.15 to 330.15) K using the synthetic method by a laser monitoring observation technique at atmospheric pressure. Its corresponding (solid + liquid) equilibrium data will provide essential support for industrial design and further theoretical studies. The solubility data of diosgenin in isopropanol, acetone, ethanol (95%), and acetic ether were correlated with Apelblat equation, and the experimental data of diosgenin in methanol and propyl acetate were also correlated with the λh model. The calculated values were good in agreement with the experimental values.     

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.     

Solubility of terephthalic acid in aqueous acetic acid from 423.15 to 513.15 K

Using the steady-state method, the solubilities of terephthalic acid(1) in binary acetic acid(2) + water(3) solvent mixtures in a specially contrived vessel have been measured as a function of temperature in the temperature range 423.15–513.15 K and solvent composition range from x₂ = 1.000 to 0.3103 (molar fraction). The experimental solubilities are correlated with the Apelblat equation. The calculated results show good agreement with the experimental solubilities.     

Equilibrium solubility of sodium 2-naphthalenesulfonate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures at temperatures from (278.15 to 323.15) K

The equilibrium solubility of sodium 2-naphthalenesulfonate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures was measured at elevated temperatures from (278.15 to 323.15) K using a steady-state method. With increasing temperatures, the solubility increases in aqueous solvent mixtures. The results of these results were regressed by a modified Apelblat equation. The dissolution entropy and enthalpy determined using the method of the least-squares and the change of Gibbs free energy calculated with the values of Δ_diffS^o and Δ_diffH^o at T = 278.15 K.     

Equilibrium solubility of sodium 3-sulfobenzoate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures at temperatures from (278.15 to 323.15) K

The solubility of sodium 3-sulfobenzoate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures was measured at elevated temperatures from (278.15 to 323.15) K by a steady-state method. The results of these experiments were correlated by a modified Apelblat equation. The dissolution enthalpy and entropy of sodium 3-sulfobenzoate in aqueous solutions of different mole fraction were obtained.     

Measurement and correlation of the solubility of genistin in eleven organic solvents from T = (283.2 to 323.2) K

The solubilities of genistin in pure solvents including tetrahydrofuran, acetone, ethyl acetate, acetonitrile, isopropanol, n-butyl alcohol, methanol, cyclohexane, n-hexane, chloroform and ethanol were determined by the high performance liquid chromatography (HPLC) analysis method at T = (283.2, 293.2, 303.2, 313.2 and 323.2) K. The fusion enthalpy of genistin was estimated by the group contribution method. The solubility data of genistin were correlated by the simplified thermodynamic model, the modified Apelblat model, λh model and NRTL (Non-Random Two-Liquid) model. The calculated values by all models were in good agreement with the experimental values and however, the NRTL model could give better correlation results than other three models.     

Phase equilibria for liquid mixtures of (benzonitrile + a carboxylic acid + water) atT = 298.15 K

(Liquid  +  liquid) equilibrium data are presented for mixtures of {benzonitrile(1)  +  acetic acid or propanoic acid or butanoic acid or 2-methylpropanoic acid or pentanoic acid or 3-methylbutanoic acid(2)  +  water(3)} atT =  298.15 K. The relative mutual solubility of each of the carboxylic acids is higher in the benzonitrile layer than in the aqueous layer. The influence of 3-methylbutanoic acid, pentanoic acid, 2-methylpropanoic acid, and butanoic acid on the solubility of the hydrocarbons in benzonitrile is greater than that of the acetic and propanoic acids. Three three-parameter equations have been fitted to the binodal curve data. These equations are compared and discussed in terms of statistical consistency. The NRTL and UNIQUAC models were used to correlate the experimental tie lines and to calculate the phase compositions of the ternary systems. The NRTL equation fitted the experimental data far better than the UNIQUAC equation. Selectivity values for solvent separation efficiency were derived from the tie line data.     

Solubility of sodium 4-nitrotoluene-2-sulfonate in (propanol + water) and (ethylene glycol + water) systems

The solubility data of sodium 4-nitrotoluene-2-sulfonate (NTSNa) in aqueous organic solutions (propanol + water) and (ethylene glycol + water) were measured at temperatures ranging from (290 to 351) K using a dynamic method. The mole fraction of water in solvent mixtures ranged from 0 to 0.8. The solubility values are correlated with the electrolyte non-random two-liquid (E-NRTL) model. From the results obtained, the E-NRTL model provides a satisfactory mathematical representation of the experimental results for the (NTSNa + propanol + water) system and an unsatisfactory result for the (NTSNa + ethylene glycol + water) system. Thus, the modified Apelblat model is applied to describe the (NTSNa + ethylene glycol + water) system also. The calculated (solid + liquid) equilibrium temperatures with the modified Apelblat model are in good agreement with the experimental results. The root-mean-square deviations of solubility temperature varied from (0.08 to 0.94) K for two models. The effect of different aqueous organic solutions on the reaction of oxidation 4-nitrotoluene-2-sulfonic acid (NTS) to 4,4′-dinitrostilbene-2,2′-disulfonic acid (DNS) was discussed.     

Experimental measurement and modelling of solubility of inosine-5′-monophosphate disodium in pure and mixed solvents

The solubility of biological chemicals in solvents provide important fundamental data and is generally considered as an essential factor in the design of crystallization processes. The equilibrium solubility data of inosine-5′-monophosphate disodium (5′-IMPNa₂) in water, methanol, ethanol, acetone, as well as in the solvent mixtures (methanol + water, ethanol + water, acetone + water), were measured by an isothermal method at temperatures ranging from (293.15 to 313.15) K. The measured data in pure and mixed solvents were then modelled using the modified Apelblat equation, van’t Hoff equation, λh equation, ideal model and the Wilson model. The modified Apelblat equation showed the best modelling results, and it was therefore used to predict the mixing Gibbs free energies, enthalpies, and entropies of 5′-IMPNa₂in pure and binary solvents. The positive values of the calculated partial molar Gibbs free energies indicated the variations in the solubility trends of 5′-IMPNa₂. Water and ethanol (in the binary mixture with water) were found to be the most effective solvent and anti-solvent, respectively.     

(Solid + liquid) equilibria of (nalkanes + ethyl 1,1-dimethylpropyl ether)

(Solid  +  liquid) equilibria (s.l.e.) have been measured atT >  280 K for (octadecane, or nonadecane, or eicosane, or heneicosane, or docosane, or tricosane, or tetracosane, or hexacosane, or heptacosane, or octacosane  +  ethyl 1,1-dimethylpropyl ether ETAE). The experimental results are compared with values calculated by means of the Wilson, UNIQUAC and NRTL equations utilizing parameters derived from the experimental s.l.e. The existence of a (solid  +  solid) first-order phase transition in hydrocarbons has been taken into consideration in the solubility calculations. The solubility of hydrocarbons in branched-chain ethers is lower than that in n -alkanes but higher than that in cycloalkanes, branched alkanes, 1-alcohols andtert -alcohols. The best correlation of the solubility data has been obtained by the NRTL equation where the average root-mean-square deviation of the solubility temperatures is 0.36 K.     

Measurement and correlation of the solubility of 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF) in different solvents

A knowledge of the solubility of 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF) in different solvents is essential for crystallization and further theoretical studies. The laser monitoring system was used for measuring the solubility of DNTF in methanol, ethanol, acetic acid, benzene, toluene and n-butanol at temperatures ranging from (298.15 to 338.15) K. Polynomial empirical equation, ideal model and modified Apelblat equation were used to correlate the experimental values. The correlated results of three correlation equations present good consistency with the experimental values. In addition, the modified Apelblat equation produced higher accuracy than the polynomial empirical equation and the ideal equation. The standard dissolution enthalpy, standard dissolution entropy and the Gibbs energy were calculated from the experimental values. The solubility values of DNTF and correlation equations from this experiment would be invoked as basic data and models regarding the crystallization process of DNTF.     

Volumetric properties of ternary (IL + 2-propanol or 1-butanol or 2-butanol + ethyl acetate) systems and binary (IL + 2-propanol or 1-butanol or 2-butanol) and (1-butanol or 2-butanol + ethyl acetate) systems

The experimental densities for the binary or ternary systems were determined at T = (298.15, 303.15, and 313.15) K. The ionic liquid methyl trioctylammonium bis(trifluoromethylsulfonyl)imide ([MOA]⁺[Tf₂N]⁻) was used for three of the five binary systems studied. The binary systems were ([MOA]⁺[Tf₂N]⁻ + 2-propanol or 1-butanol or 2-butanol) and (1-butanol or 2-butanol + ethyl acetate). The ternary systems were {methyl trioctylammonium bis(trifluoromethylsulfonyl)imide + 2-propanol or 1-butanol or 2-butanol + ethyl acetate}. The binary and ternary excess molar volumes for the above systems were calculated from the experimental density values for each temperature. The Redlich–Kister smoothing polynomial was fitted to the binary excess molar volume data. Virial-Based Mixing Rules were used to correlate the binary excess molar volume data. The binary excess molar volume results showed both negative and positive values over the entire composition range for all the temperatures.The ternary excess molar volume data were successfully correlated with the Cibulka equation using the Redlich–Kister binary parameters.     

(Solid + liquid) phase diagram for (indomethacin + nicotinamide)-methanol or methanol/ethyl acetate mixture and solubility behavior of 1:1 (indomethacin + nicotinamide) co-crystal at T = (298.15 and 313.15) K

(Solid + liquid) equilibrium data for indomethacin (IMC) and nicotinamide (NCT) in both methanol (MeOH) and methanol/ethyl acetate (EA) mixture were determined using a static method at T = (298.15 and 313.15) K under atmospheric pressure. The 1:1 (IMC + NCT) co-crystal and IMC·MeOH were found in both systems under conditions investigated. The solubility of the 1:1 (IMC + NCT) co-crystal was correlated using a mathematical model consisting of both solubility product and a complexation process. Solubility of (IMC + NCT) co-crystals as a function of co-former (NCT) concentration was evaluated. It was found that temperature has a significant effect on the formation of methanol solvate in the systems investigated. Solvate formation could be suppressed either by increasing temperature or using solvent mixtures. Additionally, the solvent mixture could level out the solubility differences between IMC and NCT, resulting in larger and more symmetric regions for the (IMC + NCT) co-crystal, which would be helpful to the development of the co-crystallization process for the 1:1 (IMC + NCT) co-crystal.     

Application of the NRTL method to correlate solubility of diosgenin

Using the synthetic method, the solubility of diosgenin in 1-hexanol and 1-heptanol was measured at temperatures from 300 K to 329 K by a laser monitoring observation technique at atmospheric pressure. The solubility data were correlated by semi-empirical equations, such as the Apelblat equation, λh model and the ideal model, which agreed well with experimental results. The fusion enthalpy and the melting point determined by differential scanning calorimeter (DSC), are −34064.2 J · mol⁻¹ and 207.09 °C for diosgenin. With collection of over 14 solvents from different references, the NRTL thermodynamic model as one of the activity coefficient models was used to correlate and predict the solubility of diosgenin. The solubility calculated for all solvents showed good agreement with the experimental results within the temperature range studied. Additionally, the solubility of diosgenin in 14 solvents is also investigated at T = 308.15 K, the results of which indicated that solubility of diosgenin in n-alkanols tends to increase with increasing alkanol chain length from methanol to 1-heptanol and n-alkanols presented higher solubility than heterogeneous alcohols for diosgenin, such as 1-butanol > isobutyl alcohol > tert-butanol and 1-propanol > isopropanol. It also shows that solubility of diosgenin decreases with the increasing polarity of solvents. Its corresponding (solid + liquid) equilibrium data will provide essential support for industrial design and further detailed theoretical studies.     

Thermodynamic properties of CO2 absorption in hydroxyl ammonium ionic liquids at pressures of (100–1600) kPa

Solubility of CO₂ in six hydroxyl ammonium ionic liquids 2-hydroxyethanaminium acetate [hea], bis(2-hydroxyethyl)ammonium acetate [bheaa], 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate [hhemea], 2-hydroxyethanaminium lactate [hel], bis(2-hydroxyethyl)ammonium lactate [bheal], 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium lactate [hhemel] at temperatures (298.15, 313.15, and 328.16) K and pressures ranging from (100 to 1600) kPa was determined. From the experimental solubility data, the Henry’s constant of CO₂ for each hydroxyl ammonium ionic liquids was estimated and reported as a function of temperature. Furthermore, enthalpy and entropy of absorption were obtained from estimated Henry’s constant. The results showed that the solubility increase with increasing pressure and decrease with increasing temperature and the solubility of CO₂ in these six hydroxyl ammonium ionic liquids was in sequence: [hea] > [bheaa] > [hel] > [bheal] > [hhemel] > [hhemea].