Solubility In Ethanol Research Articles

Pervaporative concentration of ethanol–water mixtures using heterogeneous polydimethylsiloxane (PDMS) mixed matrix membranes

The PDMS mixed matrix membranes containing 10-μm sized zeolite were prepared, characterized, and tested on the pervaporation (PV) performance for ethanol–water solutions. We found that the membrane with the zeolite mixed after the PDMS cross-linker addition (“post-addition”) was more effective at removing ethanol from the aqueous mixtures than the pristine PDMS and the PDMS–zeolite membrane made with the zeolite addition prior to the PDMS cross-linker addition. The ethanol solubility and diffusivity increased as the zeolite loading increased, and this increase contributed to a greater ethanol flux for the 30% zeolite-containing PDMS than the pristine PDMS for the same ethanol solution. The conventional flux and separation factor data were converted to permeability and selectivity values for a comparison with the data in the literature on the PV for a 10% ethanol solution. The post-addition PDMS–zeolite membrane that was prepared in the present work exhibited the highest ethanol permeability and the third greatest selectivity among the PDMS membranes, the PDMS copolymer membranes, and the PDMS-based mixed matrix membranes reported in the literature.

Partition Coefficients and Solubilities of Compounds in the Water–Ethanol Solvent System

A new method for the prediction of solubility in the water–ethanol system has been devised. The method is based on the construction of equations for the prediction of partition coefficients from water to water–ethanol mixtures, based on the Abraham descriptors for compounds. Once partition coefficients have been predicted for a particular compound, only an experimental value for the solubility in ethanol is required for the prediction of solubilities in water–ethanol mixtures. Results of predictions are comparable to the Jouyban-Acree model that requires experimental solubilities in both water and ethanol.

Reciprocal Solubility of Gasoline Fractions and Ethanol

Reciprocal Solubility of Gasoline Fractions and Ethanol

Structural Rearrangement of Ethanol-Denatured Soy Proteins by High Hydrostatic Pressure Treatment

The effects of high hydrostatic pressure (HHP) treatment (100-500 MPa) on solubility and structural properties of ethanol (EtOH)-denatured soy β-conglycinin and glycinin were investigated using differential scanning calorimetry, Fourier transform infrared and ultraviolet spectroscopy. HHP treatment above 200 MPa, especially at neutral and alkaline pH as well as low ionic strength, significantly improved the solubility of denatured soy proteins. Structural rearrangements of denatured β-conglycinin subjected to high pressure were confirmed, as evidenced by the increase in enthalpy value (ΔH) and the formation of the ordered supramolecular structure with stronger intramolecular hydrogen bond. HHP treatment (200-400 MPa) caused an increase in surface hydrophobicity (F(max)) of β-conglycinin, partially attributable to the exposure of the Tyr and Phe residues, whereas higher pressure (500 MPa) induced the decrease in F(max) due to hydrophobic rearrangements. The Trp residues in β-conglycinin gradually transferred into a hydrophobic environment, which might further support the finding of structural rearrangements. In contrast, increasing pressure induced the progressive unfolding of denatured glycinin, accompanied by the movement of the Tyr and Phe residues to the molecular surface of protein. These results suggested that EtOH-denatured β-conglycinin and glycinin were involved in different pathways of structural changes during HHP treatment.

Functional properties of protein fractions obtained from commercial yellow field pea (Pisum sativum L.) seed protein isolate

Commercial pea protein isolate was separated into water-soluble (WS), salt-soluble (SS), alkaline-soluble (AS) and ethanol-soluble (ES) fractions. AS fraction was the most abundant, constituting about 87% of the proteins in PPI followed by WS, SS and ES fractions in decreasing order. ES fraction consistently formed emulsions with a narrow range of smaller oil droplet sizes (0.6–19μm) at pH 4.0, 7.0 or 9.0 compared to a wider range of sizes for emulsions stabilised by WS, SS and AS fractions. Emulsions formed with ES fraction were also the most stable (p<0.05) over the 3h test period at all the pH values used in this work. The WS fraction had significantly highest (p<0.05) protein solubility and foaming capacity at all the pH values when compared to solubility of PPI, SS, and ES. Except for AS and ES fractions, foaming capacities of the protein fractions were higher at pH 9.0 than at pH 4.0 or 7.0.

Comb-shaped homo- and copoly(arylene ether ketones) containing hydrophilic groups in side chains

Comb-shaped poly(arylene ether ketones) containing hydrophilic fragments in side chains are synthesized through the interaction of side reactive carboxyl groups of poly(arylene ether ketones) with methyl ethers of poly(ethylene glycol). Films based on these polymers possess tensile strengths up to 89 MPa and relative elongations at break up to 340%. Comb-shaped poly(arylene ether ketones) swell in water, and some of them show solubility in ethanol and methanol.

Chemical evaluation and thermal analysis of the essential oil from the fruits of the vegetable species Pimenta dioica Lindl

The vegetal species Pimenta dioica Lindl, popularly known as Jamaican pepper, is a 6–15 m tall tree, which belongs to the Mirtaceae family. Its fruits have an essential oil of great economic value in the international market, due to its high level of eugenol (its major compound), which is largely used in chemical and pharmaceutical industries. In this work, the extraction of the essential oil from the fruits of Pimenta dioica Lindl was carried out by the hydrodistillation method, using a modified Clevenger system. It was observed that the volume of the extracted oil reaches a maximum at 4 h, with a yield of 2.7% (m/m). The essential oil was characterized by physico-chemical analyses, such as density, refraction index, ethanol solubility, color, and appearance, besides UV–vis and infrared spectroscopy and gas chromatography/mass spectrometry. Thus, eugenol was confirmed as the major component of the essential oil of Pimenta dioica Lindl (77%). The technique of differential scanning calorimetry (DSC) was used for the determination of boiling point of the sample of essential oil from the fruits of Pimenta dioica (L.).

Liquid−Liquid Equilibria of the (Water + Ethanol + Linalyl Acetate) Ternary System at Different Temperatures

Liquid−liquid equilibrium (LLE) data of the solubility curves and tie-line compositions were examined of the (water + ethanol + linalyl acetate) system at T = (298.2, 308.2, and 318.2) K and P = 101.325 kPa. The relative mutual solubility of ethanol is higher in the water phase than in the linalyl acetate phase. The consistency of the experimental tie lines was determined through the Bachman correlation equation. The experimental LLE data were satisfactorily correlated with the nonrandom two-liquid model (NRTL), and the binary interaction parameters so obtained are reported. The best results were obtained with the NRTL method, using nonrandomness parameter (α = 0.3) for the correlation. Distribution coefficients (D) and separation factors (S) were evaluated over the immiscibility region. The influence of temperature on the LLE characteristics was found to be significant at the temperatures studied.

Crystallization Kinetics of Ibuprofen from Ethanol and Aqueous Ethanol

Ibuprofen [2-(4-isobutyl-phenyl)-propionic acid] is a common analgesic pharmaceutical. It is substantially insoluble in water but quite soluble in organic solvents. Ibuprofen here has been crystallized from ethanol and aqueous ethanol. Batch experiments were undertaken from 10 to 40 oC to measure the solubility, the width of the metastable zone and the growth kinetics. The solubility in ethanol varies markedly with temperature. Generally solubilities fall as the water content increases for aqueous ethanol. At 40 oC, saturated solutions with solvent water contents from 35 to 65 % w/w show a phase separation into two liquid layers. The metastable zone width for primary nucleation is substantial, but is much narrower for secondary nucleation. None the less, growth rates in this narrow secondary metastable zone are still significant and this region, with care, can be used for non-nucleating seeded batch crystallizations. Crystal growth rates were found to be first order with supersaturation, with growth rate constants increasing with temperature [activation energy = 23.4 (±50%) kJ/mol] and within the accuracy of measurement not changing with the solvent water content.

Synthesis and structural characterization of triorganotin(IV) methoxyacetates: Correlation of ^{13}C CPMAS NMR spectroscopy with single crystal structure

The triorganotin(IV) derivatives of methoxyacetic acid, methoxyacetatotriphenyltin(IV) ( 1), methoxyac- etatomethyldiphenyltin(IV) (2), and methoxyacetatotriphenyltin(IV) (3) were synthesized by the reaction of methoxyacetic acid with Ph3SnCl, Ph2MeSnI, and Me3SnCl, respectively, with the aid of potassium iso-propoxide. Compounds 1-3 were characterized by elemental analysis, mass spectrometry, infrared spectroscopy (IR), and 1 H, 13 C, 119 Sn NMR, and 13 C CPMAS NMR. The molecular structures of the three complexes were determined by single-crystal X-ray diffraction. Crystallography shows that all three complexes adopt polymeric trans-C3SnO2 trigonal bipyramidal structures with the oxygen atoms occupying axial positions. The X-ray structures reveal two independent, non-symmetric, but essentially identical molecules in the crystal- lographic asymmetric unit of 1 and 3, in which they link to each other by a bridged methoxyacetato ligand. The 13 C CPMAS NMR spectroscopy of 1 and 3, with two sets of signals for the groups linked to tin, is consistent with the two independent trigonal bipyramids in the asymmetric unit. The prepared compounds show much higher solubility in ethanol in comparison to acetate derivatives.

Chemical Composition and Antimicrobial Activities of the Essential Oil from Glycyrrhiza glabra Leaves

The essential oil of Glycyrrhiza glabra leaves was obtained by hydrodistillation and analyzed by GC and GC-MS. Other parameters such as refractive index, optical rotation; density, polarimetric deviation; freezing point and Solubility in ethanol are also measured. The main hydrocarbon and oxygen containing compounds were: Isoniazid (13.36 %) ; Diethyltoluamide (6.56 %), Benzoic acid (5.37 %), Benzene (4.58 %), Linalool (2.25 %), Prasterone (5.63 %), Warfarin (1.43 %), Iodoquinol (1.90 %), Phenol, 4-(2-aminopropyl) (1.30 %). The screening of antibacterial activity was conducted by a disc diffusion test and the minimum inhibitory concentration was determined against Pseudomonas Aeruginosa, Salmonella typhi, Escherichia coli and Staphylococcus aureus.

Solute–solvent friction kernels and solution properties of methyl oxazoline–phenyl oxazoline (MeOx–PhOx) copolymers in binary ethanol–water mixtures

Solvent mixtures often alter the solubility of polymeric substances. Statistical copolymers made from 2-methyl-2-oxazoline (MeOx) and 2-phenyl-2-oxazoline (PhOx) are known for their varying solubilities in pure ethanol, pure water and in binary mixtures of ethanol-water. Constrained Molecular Dynamics (MD) simulations have been carried out with an aim to explain the varying solubilities of the statistical MeOx-PhOx copolymers. The solute-solvent dynamic friction kernels calculated through constrained MD simulations corroborate the solubility pattern in these copolymers. The solvation characteristics have been analyzed in terms of the solute-solvent radial distribution functions (RDFs). The ethanol-soluble MeOx-PhOx copolymers exhibit characteristic solute-composition dependence in the dynamic solute-solvent friction kernels, indicating the strength of the solute-solvent correlations. The aggressive solvation by the ethanol molecules in the binary solvent mixtures has been brought out by the O(solute)-H(ethanol) RDFs which exhibit a characteristic dependence on the ethanol content in the solvent composition. The corresponding O(solute)-H(water) RDFs are devoid of any such composition dependence. For all the MeOx-PhOx copolymers, the O-site solvation is strongly dominated by the water molecules and the N-sites are solvated equally by both ethanol and water molecules.

Solubility of Anthracene in C1−C3 Alcohols from (298.2 to 333.2) K and Their Mixtures with 2-Propanone at 298.2 K

The anthracene solubility in methanol, ethanol, 1-propanol, and 2-propanol from (298.2 to 333.2 K) and also in binary solvent mixtures of 2-propanone + C1-C3 alcohols at 298.2 K was reported. The van’t Hoff equation was used for correlation of the solubility data in monosolvents at different temperatures. The solubility of anthracene in mixed solvents was predicted using previously developed quantitative structure-property relationships (QSPR) that required knowledge of the solubility data in monosolvents. The overall mean percentage deviation of the correlated solubilities in monosolvents at different temperatures was 4.8 %. The corresponding value for solubility prediction methods in solvent mixtures varied from (8.5 to 11.9) %. Using ab initio prediction methods, the overall mean percentage deviations varied from (14.7 to 15.8) %.

IUPAC-NIST Solubility Data Series. 89. Alkali Metal Nitrates. Part 1. Lithium Nitrate

This paper is the first part in the nitrate solubility volume. The solubility data for lithium nitrate are reviewed. Where appropriate, binary, ternary, and multicomponent systems are critically evaluated. Most of the solubility results were obtained in water or aqueous solutions. The solubility in ethanol and in alcohol+water solvent mixtures is also included. All data were critically examined for their reliability. The best values were selected on the basis of critical evaluations and presented in tabular form. Fitting equations and plots are also provided. The quantities, units, and symbols used are in accord with IUPAC recommendations. The original data have been reported and, if necessary, transferred into the units and symbols recommended by IUPAC. The literature on solubility data was researched through 2007.

ChemInform Abstract: Efficient Reducing System Based on Iron for Conversion of Nitroarenes to Anilines.

AbstractThe method is especially useful for the reduction of aromatic nitro compounds with poor solubility in ethanol.

Effect of 2,2′,2′′-Nitrilotrisethanol on the Vapor−Liquid Equilibria of the Ethanol + Water System at Atmospheric Pressure

Extractive distillation processes with a variety of extracting agents such as solvents, salts, salt(s) dissolved in solvents, and organic solutes have been studied to produce anhydrous ethanol. These studies indicate that there are merits and demerits associated with each of the extracting agents identified. An organic compound, 2,2′,2′′-nitrilotrisethanol (commonly known as triethanolamine), has been identified as useful as an extracting agent for the production of anhydrous ethanol. It has infinite solubility in ethanol as well as water, and hence it can be used in any proportion. Its effect on the vapor−liquid equilibria of the ethanol + water system has been studied using an Othmer-type recirculation still. The relative volatility of ethanol + water solution of fixed composition is found to increase linearly with an increase in concentration of 2,2′,2′′-nitrilotrisethanol up to 1.55 kmol·m−3. The enhancement in relative volatility of the ethanol + water system at atmospheric pressure in the presence of 2,2′,2′′-nitrilotrisethanol at a concentration of more than about 0.88 kmol·m−3 is sufficient enough to eliminate the azeotrope formation completely. Therefore, anhydrous ethanol can be produced by the extractive distillation process employing 2,2′,2′′-nitrilotrisethanol at the concentration of more than about 0.88 kmol·m−3.

Mutual Solubility of Pseudobinary Systems Containing Vegetable Oils and Anhydrous Ethanol from (298.15 to 333.15) K

The two-phase base-catalyzed transesterification of vegetable oils with short chain alcohols is common in the production of biodiesel. The reactants (vegetable oil and ethanol) are partially soluble, and this phase behavior can significantly impact the reaction process. To better understand this phase behavior, the liquid−liquid equilibrium data for pseudobinary systems containing vegetable oils (soybean oil, sunflower oil, rice bran oil, cottonseed oil, palm olein, and palm oil) + anhydrous ethanol in the range from (298.15 to 333.15) K were determined experimentally. The mutual solubility increased as the temperature rose in all the systems examined. The equilibrium data were correlated with the NRTL model using temperature-dependent parameters which represented satisfactorily the experimental results.

Response surface methodology applied to the analysis of rice bran oil extraction process with ethanol

SummaryVegetable oils can be extracted using ethanol as solvent. The main goal of this work was to evaluate the ethanol performance on the extraction process of rice bran oil. The influence of process variables, solvent hydration and temperature was evaluated using the response surface methodology, aiming to maximise the soluble substances and γ‐oryzanol transfer and minimise the free fatty acids extraction and the liquid content in the underflow solid. It can be noted that oil solubility in ethanol was highly affected by the water content. The free fatty acids extraction is improved by increasing the moisture content in the solvent. Regarding the γ‐oryzanol, it can be observed that its extraction is affected by temperature when low level of water is added to ethanol. On the other hand, the influence of temperature is minimised with high levels of water in the ethanol.

Foaming of an Immiscible Blend System Using Organic Liquids as Blowing Agents

Foaming of blend systems is a promising approach to develop cellular materials with a set of desired properties. However, foaming of blend systems is not only a chance but also a challenge, as different polymers have to be foamed at the same foaming conditions. The best conditions during foaming are individual to each polymer and influence the obtained cellular structure. In immiscible polymer blends like poly(2,6-dimethyl-1,4-phenylene ether) (PPE) and poly(styrene-co-acrylonitrile) (SAN) the differences in glass-transition temperature (Tg) and viscosity are vast and can inhibit the foaming of the blend system. In order to minimize the above-mentioned difference in Tg and viscosity, one approach is to choose a blowing agent, which shows a selective solubility in one polymer phase, working as a selective plasticizer. The aim of the present study is to evaluate systematically the foaming behavior of immiscible PPE/SAN blend systems using ethanol and n-pentane as blowing agents. Mass uptake of ethanol and n-pentane in the PPE/SAN-blends as function of the blend composition is measured, offering a selective solubility of ethanol in SAN, while n-pentane shows a high affinity to PPE. The plasticizing effect on the blend phases PPE and SAN is theoretically estimated using the Chow-equation and the WLF-equation. After foaming the blowing agent saturated blend samples in an oil-bath at different temperatures, the density reduction and the cellular structures are analyzed and correlated to the blend morphology, the blowing agent solubility in the blend phase, the rheological properties and the glass transition temperature of the nonsaturated and saturated blend phases.

Crystallization of paracetamol from ethanol-water solutions in the presence of polymers.

We have examined the effect of polymer nature and concentration on yield and micromeritic, melting and compression properties of paracetamol crystals obtained from ethanol-water solutions using the solvent-change technique. Agar, gelatin, polyethylene-glycol (PEG) and polyvinylpyrrolidone (PVP) were the polymers used. These four polymers have different solubility in ethanol and water. It was found that the yield of crystallization may increase by up to 8% with agar, gelatin and PEG, polymers that are insoluble in ethanol, while the soluble PVP reduces yield by 14%. The size of crystals increased due to the addition of polymers and changed almost in parallel with the crystal yield for agar and gelatin. Gelatin resulted in the biggest crystals, agar in the most equidimensional (aspect ratio 1.45 and roundness 1.47) and PVP in the most elongated (aspect ratio 1.89 and roundness 2.13). PEG resulted in the most agglomerated crystals. Yield pressure, Py, decreased in the following order: agar > PEG > gelatin > PVP, which is the same order for the enthalpy of fusion. Gelatin and PEG significantly decreased the elastic recovery of tablets (0.05 level), probably due to plastic deformation of crystals and fragmentation of agglomerates, respectively. Crystallization of paracetamol in the presence of polymers by the solvent-change (ethanol-water) technique may permit increase of crystal yield, alteration of crystal shape and improvement of compression behaviour during tableting.