Binary System Ethanol Research Articles

Exploring the solvent effect on risperidone (form I) crystal morphology: A combination of molecular dynamics simulation and experimental study

The solvent effect significantly influences the morphology of a substance crystallized from the solution. It is crucial to select appropriate solvent systems to produce active pharmaceutical ingredients (API) with ideal crystal habits. In this work, the effect of different solvent systems on the crystal morphology of risperidone (form I) was investigated by combining molecular dynamics (MD) simulation with experimental studies. The crystals of risperidone (form I) were obtained from solvents via a method of slow-cooling crystallization. The modified attachment energy (MAE) model was used to predict the crystal habits of risperidone (form I) in six pure solvent systems (methanol, ethanol, 1-propanol, 2-propanol, ethyl acetate and acetone) and three binary solvent systems (ethanol + water, 2-propanol + water and acetone + water). It turns out that the MAE model has good applicability in predicting the crystal habits of risperidone (form I) in the solvents. In addition, the structure of the dominant crystal faces was analyzed to explain the solvent effect on the crystal morphology. It is found that the vast u-shape structures on the (11–1) and (011) faces can prevent the adsorption of the solute molecules, resulting in the large morphological importance of these two crystal faces. Besides, the analysis of the radial distribution function (RDF) and mean square displacement (MSD) were conducted to help understand the interactions between solvents and crystal faces. The results show that the interactions between crystal faces and solvents are composed of three types of forces, and the rapid diffusion of the solvent molecules on the (11–1) and (011) face can lead to strong interactions.

Dissolution thermodynamics and preferential solvation of genistein in some (ethanol + water) mixtures at different temperatures

The solubility of genistein was measured in the binary system of ethanol and water at temperatures ranging from 288.2 to 328.2 K. The obtained data were correlated with the modified Apelblat model, Yalkowsky model, λh model, CNIBS/R-K model, Jouyban-Acree-van’t Hoff model, and modified Wilson model and their prediction accuracy was evaluated by calculating the mean relative deviation. The thermodynamic functions, Gibbs energy, enthalpy, and entropy of solution were determined using van’t Hoff equation. Moreover, the preferential solvation was analyzed by using the solubility data at 298.2 K. The solubility of genistein in the system increased with an increase in temperature and mole fraction of ethanol in the solvent mixtures. The values for solubility of genistein are ranging from 0.47 obtained in neat water at T = 288.2 K to 5.02 obtained in absolute ethanol at T = 328.2 K. The values of Δ solnG, 0 Δ solnH0 and Δ solnH0 for the dissolution of genistein in mixtures are positive, whereas the values of Δ solnH0 in neat water and absolute ethanol are negative. The thermodynamic properties of dissolution suggest that the dissolution process is non-spontaneous and endergonic. The modified Apelblat model can provide more accurate predictive solubility of genistein in the water and ethanol mixtures, whereas Yalkowsky model calculates solubility of genistein with large deviations. Genistein is preferentially solvated by water in water-rich mixtures (0 < x 2 < 0.24) but preferential solvation by ethanol in the region of 0.24 < x 2 < 1. Overall, this work could be applied for designing and optimizing the extraction, purification, and crystallization process of genistein.

Solubility measurement, correlation and dissolution thermodynamics properties of marbofloxacin in binary solvents

Marbofloxacin (MAB) is a broad-spectrum veterinary antibacterial drug with the great application prospects. The solid-liquid equilibrium solubility of MAB in three kinds of aqueous binary solvent systems (ethanol + water, acetonitrile + water, and methanol + water) was determined between 283.15 and 323.15 K using a dynamic laser-monitoring method at atmospheric pressure. The experimental results revealed that the solubility of MAB increased with increasing temperature and mole fraction of water in the three binary solvent systems. The modified Apelblat, λh, and (non-random two-liquid) NRTL models were used to correlate the experimental data. For the ethanol + water system, the modified Apelblat model provided a better correlation with the experimental results than the other two models. However, for the acetonitrile + water and methanol + water systems, the most favorable correlation was obtained using the NRTL model. Furthermore, the van’t Hoff equation was used to study the thermodynamic properties of MAB. The obtained solubility data and thermodynamic properties of MAB can provide theoretical guidance for selecting the appropriate solvent system for the reaction, crystallization, and purification of MAB.

Isobaric vapor-liquid equilibrium for 2-butanone + ethanol + acetate-based ionic liquids at 101.3 kPa

Three acetate-based ionic liquids (ILs) (tetraethylammonium acetate, [N2,2,2,2][AC]; 1‑butyl‑2,3-dimethylimidazolium acetate, [BMMIM][AC]; or tributyl-methylammonium acetate, [N4,4,4,1][AC]) were used to separate the 2-butanone-ethanol azeotropic mixture as entrainer. The separation abilities of the three ILs were compared by measuring isobaric vapor-liquid equilibrium (VLE) data of the 2-butanone + ethanol + IL ternary systems at 101.3 kPa. The VLE data were well correlated through the use of the nonrandom two-liquid (NRTL) model. The azeotrope of 2-butanone + ethanol binary system is entirely eliminated when the concentration of IL achieves a certain value. The minimum mole fractions of the three ILs to completely eliminate azeotropic phenomena are 0.0146, 0.0166 and 0.0240, respectively. The breaking azeotropic capacities of the three ILs are better than that previously reported in the literatures. According to the average relative volatility, after the azeotropic point is thoroughly eliminated, the order of the separation capability of the three ILs is as below: [N2,2,2,2][AC] > [BMMIM][AC] > [N4,4,4,1][AC]. The σ-profiles were used to further explore the separation mechanism.

Фазовые равновесия и высаливание 2-(2-бутоксиэтокси)этанола в тройной системе нитрат калия–вода–2-(2-бутоксиэтокси)этанол

Visual polythermal method in the bynary system of water-2-(2-butoxyethoxy) ethanol in the range of –25÷0° C the ice melting line is determined and the phase equilibria in the ternary system potassium nitrate–water–2-(2-butoxyethoxy) ethanol are studied in the range of 10.0–90.0° C. The ice melting line in the water–2-(2-butoxyethoxy) ethanol binary system is a flat, smooth line. This form of the melting line shows a hidden separation in liquid mixtures. It has been found that potassium nitrate salts out 2-(2-butoxyethoxy)ethanol from water-organic mixtures, and at 31.7° C in the ternary system of potassium nitrate–water–2-(2-butoxyethoxy)ethanol, separation begins. The compositions of the solutions corresponding to the critical solubility points at several temperatures have been determined. The isothermal phase diagrams of the ternary system at 10.0, 25.0, 30.0, 31.7, 35.0, 50.0, 90.0° С have been plotted. The distribution coefficients of 2-(2-butoxyethoxy) ethanol between the liquid phases of monotectic state have been calculated. It is shown that the effect of salting-out 2-(2-butoxyethoxy) ethanol from aqueous solutions with potassium nitrate increases with increasing temperature. The concentration of 2-(2-butoxyethoxy) ethanol in the organic phase of monotectics at 90.0° C is 90 wt.% with a distribution coefficient of 897.

An investigation of physicochemical properties of Nigella sativa L. Seed oil from Al-Qassim by different extraction methods

An investigation of physicochemical properties of Nigella sativa seed oil from Al-Qassim, KSA was conducted using cold press and Soxhlet extraction methods. The effect of solvent polarity on the oil components and properties were examined using hexane, tetrahydrofuran, ethanol, dichloromethane, methanol and methanol-water binary system. The results demonstrated a high yield of oil with the Soxhlet method using ethanol (40.16%) while the samples extracted with the methanol–water binary system produced the lowest yield (28.28%). Linoleic acid was the major free fatty acid in all samples followed by oleic and palmitic acids. Moreover, the triacylglycerol analysis was carried out using a high-performance liquid chromatography system. The results revealed that the studied oil samples were rich in unsaturated triacylglycerols mostly as 3 Linoleic acid (LLL) but low in saturated triacylglycerols. Thymoquinone, which is known as a powerful antioxidative and antiradical agent was detected in all samples except the sample extracted with the methanol–water binary system. The effect of solvent polarity and the solvent boiling point was observed through the quantity of the main components of each oil sample even though they are from the same source of seed. This study showed that the aforementioned properties were affected by the polarity of the solvent used during the extraction process.

Density and Viscosity of CO2 + Ethanol Binary Systems Measured by a Capillary Viscometer from 308.15 to 338.15 K and 15 to 45 MPa

Density and viscosity of CO2 + ethanol binary systems were measured by a high-pressure capillary viscometer at different ethanol mole fractions of 0, 0.067, 0.135, 0.203, 0.271, and 1 with temperat...

Further computation and some comments on “Stearic acid solubility in mixed solvents of (water + ethanol) and (ethanol + ethyl acetate): Experimental data and comparison among different thermodynamic models”

The experimental solubility data of stearic acid in the neat solvents, ethanol + water and ethyl acetate + ethanol binary solvent systems at the temperature range from 293.15 to 323.15 K have carefully been reanalyzed and some recommendations were proposed. Further computations are performed on the stearic acid solubility data by using some cosolvency models including CNIBS/R-K, modified Wilson, NRTL, Wilson, UNIQUAC, Yalkowsky, Jouyban-Acree, and Jouyban-Acree-van't Hoff models.

Vapor-liquid equilibrium for binary systems ethanol (1) and water (2) and methyl acetate (1) and ethanol (2): Thermodynamic consistency and data prediction

Vapor-liquid equilibrium for binary systems ethanol (1) and water (2) and methyl acetate (1) and ethanol (2): Thermodynamic consistency and data prediction

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

ABSTRACT The solubility of albendazole (ABZ) in a binary system of ethanol and water were determined experimentally by using a static analytical method within the temperature range (288.95 to 317.25) K under atmospheric pressure (p = 0.1 MPa). It was observed that the solubility of ABZ is not only depended on temperature but also related to the mole fraction of ethanol. Additionally, the obtained solubility data were correlated by employing the CNIBS/R-K model, the modified Apelblat equation and the Jouyban–Acree model. The modified Apelblat equation was proven to give good representation of the experimental solubility data. On the base of the measured solubility, the thermodynamic properties of the dissolution process were calculated. Dissolution of ABZ in these mixed solvents is endothermic, non-spontaneous and enthalpy-driving. This study provides useful information for the design and development of dosage forms of ABZ.

Experimental Determination of Isobaric Vapor–Liquid Equilibrium and Isothermal Interfacial Tensions for the Binary Ethanol + Cyclopentyl Methyl Ether Mixture

This work describes the vapor–liquid equilibrium (VLE) data experimentally measured at three isobaric conditions 50, 75, and 94 kPa and over the temperature range from 334 to 375 K and the atmospheric interfacial tensions (IFT) measured at the isothermal of 298.15 K in the whole mole fraction range for the ethanol + cyclopentyl methyl ether binary system. In order to carry out the experimental determinations, a dynamic all-glass Guillespie type cell was used to carry out VLE measurements, whereas a maximum differential bubble pressure tensiometer was used to IFT determinations. Because few experimental data are available for cyclopentyl methyl ether, vapor pressures and interfacial tensions have also been measured over the temperature range 341–378 K and 298–353 K, respectively. According to the experimental results, the binary system ethanol + cyclopentyl methyl ether displays a positive deviation from the Raoult’s law with a minimum temperature azeotropic over the whole explored pressure range. The azeo...

Fabrication of carbon nanomaterials using supercritical states of ethanol and binary system of ethanol and carbon dioxide for LSI interconnects

The fabrication and filling of carbon nanomaterials (CNMs) into nanoholes and trenches using supercritical method were achieved for the first time at substrate temperatures of 500–700 °C and pressures of 10–20 MPa. Two supercritical fluid systems were examined: (1) ethanol and carbon dioxide were used as the carbon source and supercritical fluid, respectively, and (2) ethanol was used as both the carbon source and supercritical fluid. Multiwalled carbon nanotubes with diameters of 8–20 nm were also confirmed to be formed. The present work introduces a new technique of preparing CNMs for application as large-scale integration interconnects.

An effective in situ reduction strategy assisted by supercritical fluids for the preparation of graphene - polymer composites

The chemical/thermal in situ reduction of graphene oxide (GO) in GO-polymer composite is consistently challenged by the presence of undesirable chemical residues/temperature degradation restriction of the polymer. In order to tackle this problem, an effective in situ supercritical fluid reduction strategy comprising of supercritical CO2 and ethanol binary system under N2 atmosphere was developed by stepwise comparison of different reduction methods for graphene oxide-polyvinyl alcohol (GO-PVA) composite films. The resulting rGO-PVA composite films comprising of 10 wt% rGO showed an electrical conductivity of 51.7 S/m-and Young's modulus of 3.1 GPa. Different weight loadings of GO in the polymer composite films were found to affect the electrical and mechanical properties of the resulting rGO-polymer films. The in situ supercritical fluid reduction strategy was demonstrated further for successfully obtaining rGO-polyethylene glycol films (rGO-PEG) and rGO-PVA fiber.

Controlling breath figure patterns on PDMS by concentration variation of ethanol-methanol binary vapors.

In this paper, the self-assembly of condensed droplets on smooth and constrained surfaces under saturated vapor atmosphere of ethanol and methanol binary system is reported. Hexagonally ordered array of pores are obtained on smooth surfaces with saturated vapors of binary liquids without the assistance of any additives. The results show that the addition of a small amount of ethanol to methanol plays a role very similar to that of surface active agents in inducing the formation of a regular droplet array. The effect of constraints on a self-assembled droplet pattern such as the movement of the contact line and the depinning of the contact line is also investigated. It is observed that the pore size, pore shape, pore depth and ring diameter are influenced by the atmosphere of binary vapors in addition to the commonly held attribution to the surface tension of the solvent. Contact angle studies of the patterned substrates show hydrophobicity with high adhesiveness and transitions between the Wenzel and Cassie impregnating state over the entire concentration region.

Solubility Measurement and Thermodynamic Modeling of Benzoic Acid in Monosolvents and Binary Mixtures

The solid–liquid equilibrium of benzoic acid has been determined in six monosolvents—tributyl phosphate, diacetone alcohol, methyl-n-propyl ketone, methyl acetate, amyl acetate, and isooctane—at temperatures from 283.15 to 328.15 K and five binary systems—ethanol + hexane (288.15–328.15 K), isopropyl alcohol + hexane and chloroform + hexane (288.15–323.15 K), acetone + hexane (288.15–318.15 K), and acetone + water (288.15–318.15 K)—at atmospheric pressure with varying mole fraction of the binary mixture. The solubility was estimated by three different methods—titrimetry, gravimetry, and high-pressure liquid chromatography methods. The solubility of benzoic acid was found to increase with an increase in temperature and mole fraction. Experimental solubility data was correlated with various thermodynamic models such as the Buchowski equation, the NRTL model, and the modified Apelblat–Jouyban–Acree model. The mathematical models demonstrated that the calculated and experimental solubilities of benzoic acid i...

Isobaric vapor–liquid equilibrium for ternary system of ethanol, ethyl propionate and para-xylene at 101.3 kPa

Isobaric vapor–liquid equilibrium (VLE) data for the binary system ethyl propionate (2) + para-xylene (3) and ternary system ethanol (1) + ethyl propionate (2) + para-xylene (2) at atmospheric pressure (101.3 kPa) were obtained by a VLE modified othmer still. All the experimental data passed a point to point consistency test of Van Ness method, which verified the data reliability. The Wilson and UNIQUAC activity coefficient models were employed to correlate the binary VLE data to obtain binary interaction parameters. Based on binary interaction parameters, ternary VLE data of ethanol (1) + ethyl propionate (2) + para-xylene (3) were predicted by Wilson and UNIQUAC models, which proved that predicted values are consistent with the experimental data. Furthermore, azeotropic phenomenon between ethanol and ethyl propionate disappears when the mole ratio of para-xylene and binary system of ethanol and ethyl propionate is 1:1. Therefore, this paper convinced that para-xylene is a proper extractive additive that could be used in extractive distillation to separate the binary azeotropic system of ethanol and ethyl propionate.

Prediction the Solubility of Polycyclic Aromatic Hydrocarbons in Subcritical Water by Using the CPA EOS

The aim of this work is to describe the solubility of polycyclic aromatic hydrocarbons (PAHs) in subcritical water. To achieve this goal, first, a literature survey of the solubilities of PAHs in water and of naphthalene in mixtures of water and ethanol was made. Subsequently, the cubic plus association equation of state was used to describe the solubility of PAHs in the liquid phase. For accurate descriptions of the aqueous solubility of PAHs, the binary interaction parameters and cross-association volumes were regressed based on the experimental solubilities at atmospheric pressure. These regressed parameters are then used for subcritical water. Additionally, these parameters have been determined for the (naphthalene + ethanol) binary system. These regressed parameters have then been applied to predict the solubility of naphthalene in (ethanol + water) solutions. The results of the present model prove that it can be successfully applied for reproducing the solubilities of PAHs in the aqueous phase.

Vapor–Liquid Equilibrium and Excess Enthalpy Data for Systems Containing N,N-Dimethylacetamide

Isothermal P–x vapor–liquid equilibrium and excess enthalpy (HE) data were experimentally determined for the 10 binary systems hexane, heptane, 1-octene, benzene, toluene, ethanol, methanol, ethyl acetate, dibutyl ether, and dichloromethane with N,N- dimethylacetamide using the static synthetic method and isothermal flow calorimetry, respectively. The experimental data from this work together with data taken from literature were used for the extension of the group contribution method Modified UNIFAC (Dortmund).

Evidence of anomalous behavior of intermolecular interactions at low concentration of methanol in ethanol-methanol binary system

At low concentrations of methanol in a binary system of ethanol and methanol, uniquely complex molecular interactions are reported here. Previous studies indicate that ethanol molecules form aggregates held together by hydrogen bonding (O–H–O) and also dispersive forces. Addition of small amount of methanol tends to break the hydrogen bond network of ethanol due to the larger polarity of methanol. This leads to the ethanol molecules becoming somewhat isolated from each other within a scaffolding network of methanol molecules, as seen from the present molecular dynamics simulations. This is an indication of a repulsive force that dominates among the two different alcohols. At higher molar concentration of methanol (Xm > 0.3817), the strength and extent (number) of formation of hydrogen bonds between ethanol and methanol increase. The geometry of molecular structure at high concentration favors the fitting of component molecules with each other. Intermolecular interactions in the ethanol-methanol binary system over the entire concentration range were investigated in detail using broadband dielectric spectroscopy, FTIR, surface tension and refractive index studies. Molecular dynamics simulations show that the hydrogen bond density is a direct function of the number of methanol molecules present, as the ethanol aggregates are not strictly hydrogen-bond constructed which is in agreement with the experimental results.

Interfacial tension and adsorption in the binary system ethanol and carbon dioxide: Experiments, molecular simulation and density gradient theory

Data on the interfacial tension and adsorption are reported for the binary mixture of ethanol + carbon dioxide (CO2) as well as for pure ethanol. The data are obtained from experiments, molecular dynamics (MD) simulations, and density gradient theory in combination with the PC–SAFT equation of state (DGT + PC–SAFT). Experimental data of the interfacial tension are reported for 8 temperatures between 303 K and 373 K and pressures up to 6 MPa. The experimental data are compared to results from MD simulations and from DGT + PC–SAFT for which pressures up to 12 MPa are considered. From the experimental data, the relative adsorption of CO2 is obtained via the Gibbs adsorption equation using the PC–SAFT equation of state. Data on the relative adsorption of CO2 is also determined both from MD and DGT + PC–SAFT. The three data sets show good agreement. There is a substantial enrichment of CO2 at the interface. This is consistently predicted both by MD and DGT + PC–SAFT. The work shows that both MD and DGT + PC–SAFT are well suited for detailed studies of interfacial properties and that the independent methods yield similar predictions for those interfacial properties which cannot be studied experimentally.