Binary System Ethanol Research Articles

Isobaric Vapor–Liquid Equilibria for Binary Mixtures of γ-Valerolactone + Methanol, Ethanol, and 2-Propanol

γ-valerolactone (GVL) has been identified as a renewable, versatile, and nontoxic building block for the chemical industry. Although several protocols were published for its synthesis, so far only a few studies concerning the separation and purification of the product were reported. Some of the procedures involve alcohols or lead to the formation of binary mixtures of alcohols and GVL, therefore the separation is of utmost importance to produce GVL. Isobaric vapor–liquid equilibria of three binary systems (methanol, ethanol, and 2-propanol) of γ-valerolactone were measured using a vapor condensate and liquid circulation VLE still. The experimental data were correlated with Wilson and UNIQUAC activity coefficient models and the results were compared with UNIFAC model calculations. Both models were found suitable for representing the VLE data. The refractive indexes of all systems were determined in the whole concentration range at T = 293.2 and 298.2 K. Good agreements between experimental and calculated V...

Experimental and computational study of the molecular interactions between 2-chloroaniline and substituted ethanols

The intermolecular interactions between 2-chloroaniline+substituted ethanol binary liquid systems were studied both at the macro- and microscopic levels using a combined experimental and computational methodology. Thermophysical properties of 2-chloroaniline (2CA) and 2-aminoethanol (2AE), 2-chloroethanol (2CE), 2-phenylethanol (2PE) binary mixtures are studied at ambient atmospheric pressure over the entire composition range and at T=(303.15K–318.15K). Excess properties derived from the experimental ones were correlated using Redlich-Kister (RK) equation, for binary mixtures. In the present study the calculated excess properties are discussed in terms of molecular interactions of binary mixtures. The existence of the hydrogen bonding in the binary mixtures of 2-chloroaniline with substituted ethanol's were further conformed by high level theoretical calculation namely, the density functional theory (DFT-B3LYP) of 6-311++G (d, p) basis set was used to study the geometries, bond characteristics, interaction energies and noncovalent interaction plots (NCI) of the hydrogen bonded complexes in gas phase were investigated via quantum chemical calculations.

Phase behavior of novel functional tropine ionic liquids in binary solvent mixture (water + ethanol): A synergistic effect promoting solubility

Phase diagrams for the binary systems ethanol or water+tropine-type ionic liquids including N-benzyl-tropine hexafluorophosphate, N-(3-methoxybenzyl)-tropine hexafluorophosphate, N-(4-nitrobenzyl)-tropine hexafluorophosphate and related ternary systems (ethanol+water+ionic liquid) were measured with equilibrium method at atmospheric pressure in the temperature range of 278.15K to 333.15K. With the increase of temperature, the solubility of these ionic liquids increased obviously and the temperature-sensitive property in binary solvent mixture (water+ethanol) was also proven. On the other side, cosolvency phenomenon was also found in binary system. And it was found that the cosolvency related to the ratio of water and ethanol, as well as the strength of hydrogen bonding between solvent and cationic groups of ILs. The solubility of ionic liquids in the single solvent and certain concentration of binary solvent mixture was correlated by two empirical equations (Apelblat and λh) and two theoretical models (Wilson and NRTL) with good results. This study provides useful information for further research and application of these ionic liquids.

Solubility of dihydromyricetin in ethanol and water mixtures from 288.15 to 323.15 K

The solubility of dihydromyricetin in the binary system of ethanol and water was measured by using UV spectrophotometric method at the maximum absorption wavelength of 290nm from 288.15K to 323.15K. The solubility increases with temperature and mole fraction of ethanol in the binary system. The calculated solubility data of dihydromyricetin were computed by using three models, the modified Apelblat equation, the Buchowski–Książczak λH equation, and the Jouyban–Acree equation. The modified Apelblat equation and λH equation are more suitable for correlating experimental solubility data of dihydromyricetin. The activity coefficients were calculated based on the results of thermal properties of DMY (obtained by DSC), presenting good consistency with the solubility behavior. In this study, the enthalpy and entropy of a solution were evaluated using the van't Hoff equation. The course of dihydromyricetin dissolving in the binary system in the experimental temperature range was endothermic.

Solubility of naringin in ethanol and water mixtures from 283.15 to 318.15 K

The solubility of naringin in the binary system of ethanol and water was measured by using UV spectrophotometric method at the maximum absorption wavelength (UV=283nm) from 283.15K to 318.15K under atmospheric pressure. The solubility increases with the increasing temperature and in the solvent system it exhibits a synergistic effect. The modified Apelblat model was applied to correlate the experimental solubility data, and the calculated solubilities were in good agreement with the experimental results. The process of the dissolution of naringin was always endothermic, and was influenced by two mechanisms which are enthalpy-driven and entropy-driven. Non-linear enthalpy–entropy compensation was found for naringin in the binary system of ethanol and water.

Determination of the solubility and thermodynamic properties of wedelolactone in a binary solvent of ethanol and water

Experimental solubility data of wedelolactone in a binary system of ethanol and water from 278.15K to 323.15K were measured using a thermostatted reactor by static method and HPLC analysis. The effects of binary solvents composition and temperature on the solubility were discussed and it was found that wedelolactone solubility in (water+ethanol) mixed solvents presented a monotonic effect in the studied region. The measured data were regressed by the modified Apelblat equation, Wilson model, nonrandom two-liquid (NRTL) model and the binary solvent (CNIBS)/Redlich–Kister model, and the maximum ∑(%D) values were 0.75, 1.90, 4.34 and 0.38, respectively. The correlation results showed that calculated values by the four models agree well with the experimental data. Using the experimentally measured solubility values, the thermodynamic properties of dissolution of the wedelolactone, including Gibbs energy change (ΔGd), molar enthalpy change (ΔHd) and molar entropy change (ΔSd) of dissolution, were calculated. The values of the standard molar Gibbs energy change and standard enthalpy molar change of solution were both positive, which indicated that the dissolution of wedelolactone in the binary system of ethanol and water was endothermic and no-spontaneous process.

Fluorescent properties of 8-phenylBODIPY in ethanol - ethylene glycol mixed solutions.

Fluorescent characteristics of two BODIPY dyes in solutions were investigated under the viscosity variations. Investigated dyes differ in the nature of 8-substituent of ligand molecule. Viscosity variation was achieved by changing of solvent composition in the binary system ethanol - ethylene glycol and solvent temperature. 8-Phenyl substituted BODIPY is found to exhibit properties of molecular rotor, i.e. its fluorescent characteristics are highly dependent on the viscosity or rigidity of the microenvironment. Increased temperature leads to a linear decrease of fluorescence parameters unlike the solvent composition variation where fluorescence change is nonlinear. The highest specific change in the fluorescence was observed in pure ethanol. Change in the nonradiative decay rate constant values with the increasing of viscosity indicates that the analyzed phenyl substituted complex is a true molecular rotor. Investigated 8-phenylBODIPY could be recommended as promising viscosity sensor in different organic media.

Hydrogen bonding interactions in ethanol and acetonitrile binary system: A near and mid-infrared spectroscopic study

The hydrogen bond interactions in C2H5OHCH3CN binary system have been studied in detail by near-infrared spectroscopy (NIR), attenuated total reflection (ATR) mid-infrared spectroscopy (mid-IR), and density functional theory (DFT) calculations. The collected spectra were analyzed with excess spectroscopy and two-dimensional correlation spectroscopy (2D-COS) including moving-window 2D-COS. The main conclusions are: (1) A number of species, namely multimer, trimmer, and dimer of C2H5OH, and C2H5OH⋯CD3CN hydrogen bonding complex, have been identified in the binary system C2H5OHCH3CN experimentally. The linear relationship between the observed and calculated wavenumbers of the concerned species assisted us in doing the assignments. (2) Adding acetonitrile, the hydrogen bonds in C2H5OH are weakened and C2H5OH multimers dissociate. Meanwhile, C2H5OH dimers and C2H5OH⋯CD3CN hydrogen bonding complex form, and the former also transform to the latter. The dissociation of C2H5OH multimers slows down gradually during the dilution process and at the mole fraction 0.7 of acetonitrile, all the C2H5OH multimers have dissociated.

Cyclic growth and dissolution of camphor crystals in quinary, ternary, and binary solutions: A study on crystal behavior in storm glass

“Storm glass” is a hermetically sealed glass tube containing a solution of camphor. In 19th-century England, the pattern and quantity of the crystals were observed and interpreted as a weather forecasting tool. In the present study, the appearance of camphor crystals under cyclic temperature change was studied in three sample solutions, the storm glass solution (quinary system), camphor–ethanol–water (ternary system), and camphor–ethanol (binary system), to elucidate the effect of components in the storm glass on the appearance of camphor crystals. Equilibrium temperatures of camphor crystals as a function of the camphor concentration were also obtained to estimate the quantity of camphor crystals precipitated in the solutions. During the temperature cycles, the crystal height increased and decreased. The ranges (local maxima and minima) of crystal heights gradually decreased to approximately a constant range. Not only the crystal height but also the amplitude of the height variation in the quinary and ternary systems were much larger than those in the binary system, although the estimated weights of crystals precipitated in the quinary and ternary systems were smaller than that in the binary system. This fact resulted from the formation of dendrites in the quinary and ternary systems, which caused high porosity of sedimented crystals.

Density and Viscosity of the Binary Systems Ethanol + Butan-1-ol, + Pentan-1-ol, + Heptan-1-ol, + Octan-1-ol, Nonan-1-ol, + Decan-1-ol at 0.1 MPa and Temperatures from 283.15 K to 313.15 K.

This article presents experimental viscosity and density data for binary systems containing ethanol and one of the following 1-alkanols as the second component: butan-1-ol, pentan-1-ol, heptan-1-ol, octan-1-ol, nonan-1-ol, and decan-1-ol. These properties were measured at 0.1 MPa and at five different temperatures, ranging from 283.15 K to 313.15 K. The viscosity data have also been correlated by a model which combines Eyring’s theory of viscous flow with a thermodynamic framework (Ind. Eng. Chem. Res. 2000, 39, 849). The model binary interaction parameters, for each of the binary systems, are also reported. The agreement between calculated and experimental data was rather good. The overall mean relative standard deviations did not exceed 0.01. The experimental viscosity deviations, obtained by the difference between the viscosity of the mixture and the mole fraction average of the pure component viscosities, were adjusted by means of Redlich–Kister polynomials. For all the systems studied negative values of viscosity deviations were obtained, for all temperatures, and over the whole mole fraction range.

Isobaric Vapor–Liquid Equilibrium and Isothermal Interfacial Tensions for the System Ethanol + 2,5-Dimethylfuran

This work reports isobaric vapor–liquid equilibrium (VLE) data experimentally determined at (50, 75, and 94) kPa and over the temperature range (334 to 364) K together with atmospheric interfacial tensions (IFT) measured at 298.15 K for the binary system composed by ethanol + 2,5-dimethylfuran. VLE determinations were carried out in a dynamic VLE cell, whereas a maximum differential bubble pressure tensiometer was used for performing IFT measurements. According to the experimental results, the binary system ethanol + 2,5-dimethylfuran exhibits positive deviation from ideal behavior and azeotropic behavior can be observed over the whole determined pressure range. The concentration of the azeotrope enriches in ethanol as pressure (and/or temperature) increases. The interfacial tension in turn, exhibits positive deviation from the linear behavior. The reported VLE data of the binary mixture are thermodynamically consistent according to Fredenlund’s test and were well correlated by traditional activity coeffi...

Thermodynamic study of complex formation between 3,5-di iodo-hydroxy quinoline and Zn2+, Ni2+ and Co2+ cations in some binary solvents using a conductometric method

The complexation reactions between 3,5-di iodo-8-hydroxy quinoline (IQN) and Zn2+, Ni2+ and Co2+ were studied in dimethylformamide (DMF)-ethanol (EtOH) binary solvent systems at different temperatures using a conductometric method. The stoichiometry of complexes was established 1:1. It was found that the stability of complexes formed between cations and this ligand increases with increases temperature. The standard enthalpies and standard entropies of complexes were obtained from the temperature dependence of stability constants. The results obtained by conductometric technique show that there is an inverse relationship between the formation constants of complexes and donor number of solvents. In all cases, the formation constants increased with increasing amounts of EtOH versus DMF in these binary systems. The standard enthalpy and standard entropies of complexes were obtained from the temperature dependence of stability constant. In all cases, ΔH° was positive and ΔS° was negative. The selectivity order for IQN complexes among various neat studied solvents varies in the order: Zn–IQN2+› Ni–IQN2+›Co–IQN2+.

Measurement and correlation of the solubility of 6-chloro-3-aminopyridazine in water and binary mixtures of water + ethanol from 293.55 K to 342.95 K

The solubility of 6-chloro-3-aminopyridazine in water and (water+ethanol) binary system was measured from 293.55K to 342.95K using a synthetic method. The fusion point temperature and enthalpy of fusion were determined by differential scanning calorimetry. The experimental solubility data were regressed by modified Apelblat, λh and polynomial empirical equations. Apelblat and empirical polynomial equations are in good agreement with all experimental data with the root-mean-square deviation being less than 1.69%. In addition, the activity coefficients and molar enthalpy of dissolution 6-chloro-3-aminopyridazine were obtained.

Solubility of glycine in binary system of ethanol + water solvent mixtures: Experimental data and thermodynamic modeling

The solubility of glycine in different compositions of ethanol–water binary solvent mixtures was measured over the temperature range of (278.15–328.15) K at intervals of 5.00K by employing an analytical stirred-flask method. The solubility data were fitted using the modified Apelblat equation and the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) equation, respectively. The modified Apelblat equation was found to regress the solubility data much better than the other two equations. The Van’t Hoff equation was used to calculate the apparent molar enthalpy and the apparent molar entropy of solution in the binary mixture solvent system, the dissolving process was endothermic and entropy-driving. The experiment results and correlation models could be used as essential data in the purification of glycine.

Solubility of Naringenin in Ethanol and Water Mixtures

The solubility of naringenin in the binary system of ethanol and water was measured by an ultraviolet spectrophotometer at 288 nm (the maximum absorption wavelength) from (283.15 to 323.15) K. The increasing solubility was correlated with the increasing temperature and the increasing mole fraction of ethanol in the solvent system. In the investigated experimental temperature range, the course of naringenin dissolving in the binary system was endothermic. The calculated solubility of naringenin showed good consistency with the experimental values.

Liquid–liquid and vapor–liquid equilibrium data for biodiesel reaction–separation systems

This work reports experimental vapor–liquid and liquid–liquid equilibrium data for binary and ternary systems comprised of various mixtures of biodiesel (from soybean oil), methanol, ethanol, glycerol and soybean oil. The binodal curves for biodiesel+methanol+glycerol, biodiesel+ethanol+glycerol, biodiesel+methanol+soybean oil and biodiesel+ethanol+soybean oil systems were obtained at two different temperatures by titration. An Othmer-type ebulliometer was used for vapor–liquid equilibrium measurements at pressures ranging from 14.0kPa to 92.0kPa. Binodals curves (LLE) indicated that the temperature range used in this study has no effect on the immiscibility region for the biodiesel+methanol+soybean oil system. By contrast, for the biodiesel+ethanol+soybean oil system, the immiscibility region was larger at the lower temperature. For the vapor–liquid equilibrium data, the results showed that the addition of glycerol to the biodiesel+ethanol binary system does not significantly affect the boiling temperature of the system while with the addition of methanol to the biodiesel+soybean oil system the boiling temperatures of the ternary mixture are reduced. These results can be used to enhance the reaction conversion and the purification processes associated with biodiesel production.

Solubility of daidzein in the binary system of ethanol and water

The solubility of daidzein in the binary system of ethanol and water was measured by UV spectrophotometric method from 288.2K to 328.2K. The solubility of daidzein increases with temperature and the ethanol content of the mixture. The solubility data were correlated with a modified Apelblat equation. From solubilities of daidzein, the enthalpy and entropy of solution were evaluated using van't Hoff equation.

Compressed-liquid densities of two highly polar + non-polar binary systems

The binary systems ethanol+2,2,4-trimethylpentane and 2-butanol+2,2,4-trimethylpentane were studied as models for blends of gasoline with biofuels. Their densities were measured with a vibrating-tube densimeter at compressed-liquid states of three compositions of each of the binary systems. The temperature and pressure ranges of the measured data are from 270K to 470K, and 0.5MPa to 50MPa. There are no compressed-liquid density data for the binary system ethanol+2,2,4-trimethylpentane in the literature, thus data reported here are compared to literature data at atmospheric pressure in order to establish their quality. No literature data for the system 2-butanol+2,2,4-trimethylpentane were found, thus data reported here fill a void and help to further the understanding of molecular interactions in binary systems of a polar and a non-polar compound.

Solubility of osthole in a binary system of ethanol and water

The solubility of osthole in a binary system of ethanol and water was measured by UV spectrophotometry from 288.2 to 328.2K. The solubility of osthole in the system increased with temperature. A synergistic effect appeared at x2=0.5527 (equivalent to 80% ethanol, v/v) binary mixtures. Solubility data correlated with a modified Apelblat equation. The enthalpy and entropy of solution of osthole were evaluated using van’t Hoff plots.

Densities, Viscosities, Refractive Indexes, and Surface Tensions for Mixtures of Ethanol, Benzyl Acetate, and Benzyl Alcohol

Densities, viscosities, refractive indexes, and surface tensions of the ternary system (ethanol + benzyl acetate + benzyl alcohol) at T = 303.15 K and its constituent binary systems (ethanol + benzyl acetate, ethanol + benzyl alcohol, and benzyl acetate + benzyl alcohol) at T = (293.15, 303.15, 313.15, and 323.15) K were measured under atmospheric pressure. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic microviscometer based on the rolling-ball principle. Refractive indexes were measured using a digital Abbe-type refractometer. Surface tensions were determined by the Wilhelmy-plate method. From these data, excess molar volumes, deviations in viscosity, deviations in refractive index, and deviations in surface tension were derived. The results for the binary and ternary systems were fitted to the Redlich–Kister equation and the Cilbuka equation, respectively. The excess molar volumes and deviations in viscosity are used to study the nature of mixing...