Binary Solvent Mixtures Of Methanol Research Articles

Solubility study, model correlation and thermodynamics of 3-acetyl-4-hydroxy-2H-chromen-2-one and its chlorinated derivatives in binary solvent mixtures at temperatures from 293.15 to 313.15 K

The solubility of 3-acetyl-4-hydroxy-2H-chromen-2-one (GK-1), 3-acetyl-6-chloro-4-hydroxy-2H-chromen-2-one (GK-2), and 3-acetyl-7-chloro-4-hydroxy-2H-chromen-2-one (GK-3) in binary solvent mixtures of methanol and ethanol was investigated using the gravimetric method over a temperature range of 293.15 K to 313.15 K under atmospheric pressure. Experimental results showed that the mole fraction solubility of GK-1, GK-2, and GK-3 increased with rising temperature and higher co-solvent proportions (0.10 to 0.90 mol fraction). Theoretical mole fraction solubility predictions were made using the Apelblat, Van’t Hoff, Yaws, CNIBS/R-K, and modified Jouyban-Acree models, all of which showed good agreement with the experimental data. Additionally, apparent thermodynamic modeling of GK-1, GK-2, and GK-3 was conducted using the Van’t Hoff equation. The solubility and thermodynamic data obtained are valuable for the processes of production, isolation, separation, and crystallization of these compounds.

Experimental measurement and thermodynamic modelling of ethenzamide solubility in three binary solvent systems

The solid–liquid phase equilibrium of ethenzamide (ETZ), a classic anti-inflammatory drug, in binary solvent systems was experimentally investigated and simulated. The equilibrium solubility of ETZ in binary solvent mixtures of methanol + acetonitrile, ethanol + acetonitrile, and isopropanol + acetonitrile was determined via a gravimetric method at temperatures ranging from 293.15 K to 323.15 K at atmospheric pressure (0.1 MPa). In all binary solvent systems, the solubility of ETZ increases with the increasing of temperature at a given solvent composition, but it initially increased and then decreased with the increase in alcohol composition (good solvent). Additionally, the Jouyban-Acree, van’t Hoff-Jouyban-Acree, Apelblat-Jouyban-Acree, and Ma models were utilized to correlate the experimental data. Results showed that the Jouyban-Acree model achieved the best correlation performance. Molecular dynamic simulation and radial distribution function analysis revealed the cooperation effect originating from solute-solvent and solvent–solvent interactions, which explained the dissolution behaviors of ETZ in various solvent mixtures. Calculations of dissolution thermodynamic properties, including enthalpy, Gibbs free energy, and entropy, revealed that the dissolution behavior of ETZ was an endothermic and entropy-driven process. This study provides insights into modulating ETZ crystallization and in understanding solid–liquid phase equilibrium behaviors in mixed solvent systems.

Thermodynamic analysis and molecular dynamic simulation of the solubility of saccharin in three binary solvent mixtures

The equilibrium solubility of saccharin in binary solvent mixtures of methanol + acetonitrile, ethanol + acetonitrile, and isopropanol + acetonitrile was determined by using a gravimetric method within the temperature range from 293.15 K to 323.15 K at atmospheric pressure. Intriguingly, the solubility exhibits a maximum value at around 0.5 mol fraction of alcohols in all the solvent systems regardless of temperature. The cooperation effect between the solute-solvent interaction and solvent-solvent interaction was revealed by the molecular simulation study to give the explanation for the dissolving ability of saccharin in solvent mixtures. Moreover, the experimental solubility data was correlated by the Jouyban-Acree model, van’t Hoff-Jouyban-Acree model and Apelblat-Jouyban-Acree model, and the Jouyban-Acree model provides the best fitting performance. Furthermore, the dissolution thermodynamic properties of apparent standard dissolution enthalpy, Gibbs free energy and entropy were computed, and the results indicate that the dissolution process of saccharin is non-spontaneous, endothermic and entropy-driven.

Measurement and Correlation of Solubility of Hydrochlorothiazide in Monosolvents and Binary Solvent Mixtures from 283.15 to 323.15 K

In this paper, the solubility of hydrochlorothiazide (HCT) was determined by using a laser method in pure solvents (methanol, ethanol, n-propanol, isopropanol, acetonitrile, ethyl acetate, water, 2-butyl alcohol, 1-pentanol, and isobutyl alcohol) and binary solvent mixtures of methanol + water and acetonitrile + n-propanol at the temperatures ranging from 283.15 to 323.15 K in approximately 5 K intervals at atmospheric pressure. The solubility increases with increasing temperature in all pure solvents we chose. However, the solubility of HCT increases with increasing methanol content, and it increases first and then decreases with increasing acetonitrile content at constant temperature. The dissolving capacity of HCT ranks as methanol > acetonitrile > ethanol > ethyl acetate > n-propanol (isopropanol) > 2-butyl alcohol (isobutyl alcohol) > 1-pentanol > water. The experiment data were well correlated with the modified Apelblat equation, λh equation, NRTL equation, and modified Jouyban–Acree model.

Solute-solvent and solvent-solvent interactions and preferential solvation of limonin in aqueous co-solvent mixtures of methanol and acetone

Solute-solvent and solvent-solvent interactions of limonin in binary solvent mixtures of methanol + water and acetone + water were investigated from the solubility data by using the linear solvation energy relationships concept. The variation of limonin solubility depended mainly upon the hydrogen bond basicity for methanol (1) + water (2) mixtures, and the cavity term for acetone (1) + water (2) mixtures. The preferential solvation parameters (δx1,3) of limonin in two solvent mixtures were derived by means of the inverse Kirkwood–Buff integrals method. δx1,3 values were negative in water-rich mixtures but positive in solvent compositions from 0.24 or 0.20 (0.25) to 1 in mole fraction of methanol or acetone, respectively. It was conjecturable that in water-rich mixtures, the hydrophobic hydration around the nonpolar methyl groups of limonin played a relevant role in the solvation. The preference of limonin in water-rich mixtures could be explained in terms of the higher basic behavior of limonin molecules interacting with the proton-donor functional groups of the water.

Solubility and preferential solvation of econazole nitrate in binary solvent mixtures of methanol, ethanol and 1,4-dioxane in water

The solubility of econazole nitrate in binary mixed solvents of (methanol+water, ethanol+water and 1,4-dioxane+water) were measured experimentally via the isothermal dissolution equilibrium method in the temperature range of (278.15–318.15) K under 101.2kPa. For the (1,4-dioxane+water) system, at a certain composition of 1,4-dioxane, the solubility of econazole nitrate increased with an increase in temperature; nevertheless at the same temperature, they increased at first and then decreased with an increase in mass fraction of 1,4-dioxane. At the same temperature and mass fraction of methanol, ethanol or 1,4-dioxane, the solubility of econazole nitrate was greater in (methanol+water) than in the other two mixed solvents. The solubility values were correlated by using Jouyban-Acree model, and the dissolution enthalpies of the dissolution process were computed. Preferential solvation parameters of econazole nitrate were also derived by means of the inverse Kirkwood-Buff integrals method. The preferential solvation parameter by water δx1,3 is negative in water-rich mixtures but positive in compositions from 0.31 to 1.0 in mole fraction of methanol and from 0.24 to 1.0 in mole fraction of ethanol. It is conjecturable that in intermediate composition of alcohol and alcohol-rich mixtures the interaction by acidic hydrogen-bonding by methanol/ethanol on the basic sites of econazole nitrate played a relevant role in the drug solvation. However in 1,4-dioxane (1)+water (2) mixtures with 0.18<x1<0.50 positive δx1,3 values were observed, but with 0.50<x1<1.0 negative δx1,3 values were observed again. The solubility data presented in this work expand the physicochemical information about drugs in binary aqueous-co-solvent mixtures.

Determination and Correlation of Solubility of Phenylbutazone in Monosolvents and Binary Solvent Mixtures

In this paper, we focused on the solubility of phenylbutazone, which was characterized by FT-IR spectra and X-ray diffraction. By the method of a laser technique, the solubility of phenylbutazone was measured in 10 monosolvents (methanol, ethanol, 2-propanol, n-butanol, 1-pentanol, n-hexanol, acetonitrile, ethyl acetate, acetone, and DMF) and 2 binary solvent mixtures of methanol + acetone and ethanol + acetonitrile from 283 to 323 K at about 5 K intervals under atmospheric pressure. The results show that the solubility of phenylbutazone in monosolvents and mixed solvents increases with the increase of temperature. However, it decreases with the increasing initial mole fraction of alcohols in the selected mixed solvents at constant temperature. The experimental data were correlated by the modified three-parameter van’t Hoff equation and the modified Jouyban–Acree equation.

Measurement and Correlation of Solubility of Loratadine in Different Pure Solvents and Binary Mixtures

The solubility of loratadine in pure solvents and binary mixed solvents is measured at the temperature range from 283.15 to 323.15 K using a laser technique. The results indicate that the solubility of loratadine increases with the increasing temperature in all these selected solvents. The solubility of loratadine reaches the maximum value when the mole fraction of methanol is 0.7 in the binary solvent mixtures of methanol + acetonitrile. Also, in the system of n-pentanol + acetonitrile mixed solvent the solubility reaches the maximum value when the mole fraction of n-pentanol is 0.6. The modified Apelblat equation and three parameters van’t Hoff equation are applied to correlate the experimental solubility in pure solvents. In binary mixed solvents, the modified Apelblat equation and Jouyban-Acree model are used to correlate the solubility data.

Solubilities of Naringin Dihydrochalcone in Pure Solvents and Mixed Solvents at Different Temperatures

Naringin dihydrochalcone (naringin DC) is an intense sweetener and a strong antioxidant with potential applications in many food and pharmaceutical products. However, the poor solubility and stability of naringin DC in aqueous systems at room temperature severely limits its applications in these areas. The solubility of naringin dihydochalone was quantified in water, ethyl acetate, binary solvent mixtures of methanol + water and ethanol + water by a synthetic method at different temperatures. The solubility of naringin DC in a given solvent increases with the rising temperature. The experimental data were well correlated with an Apelblat equation and Universal Quasichemical model. Moreover, the physical properties and crystal habit of naringin DC were discussed through a thermogravimetric analyzer, a differential scanning colorimeter, and a scanning electron microscope.

Measurement and prediction of dabigatran etexilate mesylate Form II solubility in mono-solvents and mixed solvents

UV spectrometer method was used to measure the solubility data of dabigatran etexilate mesylate (DEM) Form II in five mono-solvents (methanol, ethanol, ethane-1,2-diol, DMF, DMAC) and binary solvent mixtures of methanol and ethanol in the temperature range from 287.37K to 323.39K. The experimental solubility data in mono-solvents were correlated with modified Apelblat equation, van’t Hoff equation and λh equation. GSM model and Modified Jouyban-Acree model were employed to correlate the solubility data in mixed solvent systems. And Regressed UNIFAC model was used to predict the solubility of DEM Form II in the binary solvent mixtures. Results showed that the predicted data were consistent with the experimental data.

Solubility Measurement and Correlation for 2-Naphthaldehyde in Pure Organic Solvents and Methanol + Ethanol Mixtures

The solubility behavior of 2-naphthaldehyde in six pure solvents (methanol, ethanol, isopropanol, n-butyl alcohol, n-heptane, and n-hexane) and binary solvent mixtures of methanol + ethanol with various concentrations were experimentally studied by the equilibrium method at temperatures ranging from (283.15 to 313.15) K and (283.15 to 308.15) K, respectively, under an atmosphere pressure of 0.1 MPa. The solubilities of 2-naphthaldehyde in the pure solvents accord with the following order: ethanol > isopropanol > n-butyl alcohol > methanol > n-heptane > n-hexane. In the mixed solvents, the solubility of 2-naphthaldehyde increases with decreasing mass fraction of methanol. All of the solubility data were correlated with the van’t Hoff equation, the modified Apelblat equation, and the λh equation. The correlation results with the modified Apelblat equation showed better agreement with the experimental values than those with the other two models. Furthermore, the thermodynamic properties of the dissolution process of 2-naphthaldehyde were also calculated and discussed.

Solubility of Tris(hydroxymethyl)aminomethane in Methanol + 1-Propanol Mixtures at Various Temperatures

Solubility of tris(hydroxymethyl)aminomethane (TRIS) in various mass fractions of binary solvent mixtures of methanol and 1-propanol [at (293.2, 298.2, 303.2, 308.2, and 313.2) K] was measured and mathematically represented using the Jouyban-Acree model. The correlated mole fraction solubilities are in good agreement with the corresponding experimental values with an overall mean percentage deviation of 1.7%. Densities of saturated solutions of TRIS in pure methanol and 1-propanol at various temperatures were measured and employed to predict the density of saturated solutions of TRIS in their binary solvent mixtures.

Solubility of Phenanthrene in Binary Mixtures of C1−C4 Alcohols at 298.2 K

Experimental solubilities are reported for phenanthrene in binary solvent mixtures of methanol + 1-propanol, methanol + 1-butanol, ethanol + 1-propanol, ethanol + 1-butanol, and 1-propanol + 1-butanol at 298.2 K. Results of these measurements were used to evaluate the prediction capability of previously developed quantitative structure−property relationships employing the solubility data in monosolvents and the mean deviations (MDs) of the models' predicted values from the measured data varied between (1.7 and 42.5) %. The overall MDs (OMDs) for the prediction methods were 2.8 (± 2.7) % and 14.3 (± 23.3) %, respectively, for water-to-solvent and gas-to-solvent coefficients. Using ab initio prediction methods, the MDs varied between (6.2 and 155.8) %, and the OMDs were 11.4 (± 6.5) % and 92.1 (± 48.0) %.

Ultrasonic degradation of poly(acrylic acid)

AbstractThe ultrasonic degradation of poly(acrylic acid), a water‐soluble polymer, was studied in the presence of persulfates at different temperatures in binary solvent mixtures of methanol and water. The degraded samples were analyzed by gel permeation chromatography for the time evolution of the molecular weight distributions. A continuous distribution kinetics model based on midpoint chain scission was developed, and the degradation rate coefficients were determined. The decline in the rate of degradation of poly(acrylic acid) with increasing temperature and with an increment in the methanol content in the binary solvent mixture of methanol and water was attributed to the increased vapor pressure of the solutions. The experimental data showed an augmentation of the degradation rate of the polymer with increasing oxidizing agent (persulfate) concentrations. Different concentrations of three persulfates—potassium persulfate, ammonium persulfate, and sodium persulfate—were used. It was found that the ratio of the polymer degradation rate coefficient to the dissociation rate constant of the persulfate was constant. This implies that the ultrasonic degradation rate of poly(acrylic acid) can be determined a priori in the presence of any initiator. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Investigation on the influence of methanol on adsorption and leaching of pesticides with soil column liquid chromatography

The effect of methanol of low concentration on adsorption and leaching of atrazine and tebuconazole was studied in this paper. The adsorption coefficients and the retardation factors ( R m) of pesticides on EUROSOIL 3# log-linearly decreased as volumetric fraction of methanol ( f c) was increased in the binary solvent mixtures of methanol and water. These data are consistent with solvophobic theory formerly outlined for describing the adsorption and transport of hydrophobic organic chemicals from mixed solvents. Nevertheless, the adsorption of these pesticides in soil–water system slightly increased when the soil was pre-washed with methanol in comparison with that pre-washed with water (pure water system). Furthermore, their adsorption coefficients were still higher in binary solvent systems with methanol of very low concentrations, i.e. f c<0.03 for atrazine and f c<0.01 for tebuconazole, than those in pure water system. The adsorption coefficients (log K w) of atrazine and tebuconazole predicted by solvophobic theory were 0.5792 and 1.6525, respectively, and their experimental log K w were 0.3701 and 1.6275 in pure water system. Obviously, the predicted log K w of the two pesticides was higher than the experimental log K w in pure water system. The predicted K w and the retardation factor ( R w) in pure water system by solvophobic theory are thus possibly inaccurate.

Excess enthalpies of binary solvent mixtures of methanol, ethanol and 1-propanol with formamide, N-methylformamide and N,N-dimethylformamid

The excess molar enthalpies of binary solvent mixtures of methanol, ethanol and 1-propanol with formamide, N-methylformamide and N, N-dimethylformamide were measured with a flow microcalorimeter at 313.15 K. The excess enthalpies are negative for the methanol-formamide system and positive for the other systems. The partial excess molar enthalpies have also been evaluated. The results are compared with those for mixtures of the same alcohols with N-methylacetamide and N, N-dimethylacetamide and they are discussed with regard to the associating abilities of the components.

Selective solvation of silver(I) bromate in methanol—acetonitrile and ethanol—acetonitrile mixtures at 30°C

The selective solvation of silver(I) bromate in the binary solvent mixtures of methanol + acetonitrile and ethanol + acetonitrile has been studied at 30°C by solubility and emf measurements. The solubility of the salt increases with the addition of acetonitrile up to a mole fraction ( X AN) of 0.6 and 0.7 in the case of methanol + acetonitrile and ethanol + acetonitrile respectively and then decreases with further addition of the same. The transfer free energy of the silver ion (molal scale) decreases continuously with the addition of acetonitrile in both the mixtures. The transfer free energies of bromate ion (molal scale) are found to be quite small up to X AN ≈ 0.7 in both methanol + acetonitrile and ethanol + acetonitrile mixtures and then increase. The solvent transport number Δ, of acetonitrile is positive with a maximum at X AN = 0.55 (Δ = 2.7) and at X AN = 0.45 (Δ = 2.2) for methanol + acetonitrile and ethanol + acetonitrile systems respectively. These results have been interpreted as arising due to a heteroselective solvation of the salt with the silver ion being preferentially solvated by acetonitrile and the bromate ion by the amphiprotic component which is marked especially at higher compositions.