Acetone System Research Articles

Оценка вклада в объемно-термические свойства бинарных систем на основе модели зернистой среды

The paper focuses on the analytical expressions obtained for the volumetric coefficient of thermal expansion depending on the differences in the geometric structure of the initial monosystems, i.e., the geometric factor, for binary systems with a ratio of the particles volumes in the range from 1 to 8, simulated by a granular medium. Within the research, we established the reasons for the differences between the apparent excess function and the excess function of the volumetric coefficient of thermal expansion. In systems consisting of molecules that differ significantly in shape, the main contribution to this difference is made by the different behavior of the packing coefficients of the molecules of the mixed components with temperature, while in systems where molecules are of similar shape the main contribution is made by the difference in their sizes. We estimated the geometric factor contribution to the concentration behavior of the excess functions of the molar volume and the volumetric coefficient of thermal expansion in the water--acetone system, and found that the degree of its influence on the behavior of the excess functions of these properties varies significantly.

Experimental Measurements of the {CO2 (1) + Acetone (2) + Ivermectin (3)} System at High Pressure

For potential application to the controlled release of ivermectin from nanoparticle preparations, this study discloses experimental data on the phase transitions in the CO2, acetone, and ivermectin system subjected to high pressures. The data were acquired via the static synthetic method with a variable-volume view cell in the temperature range of 303.15–333.15 K at pressures up to 10 MPa using three concentrations of ivermectin B1a in acetone (0.029, 0.043, and 0.058 mol·kg–1) and CO2 molar fractions of 0.3–0.9. Vapor–liquid-type phase transitions were observed, characterized as bubbles in the presence or absence of a solid phase. A solid phase was formed for all ivermectin B1a concentrations evaluated in this study. Determination of the region of precipitation of ivermectin is important for identifying the concentration of the acetone/ivermectin mixture where CO2 will act strongly as an antisolvent. Thermodynamic modeling was performed by considering the system as pseudo-ternary based on the low concentration of ivermectin B1a in the system. Thermodynamics modeling using the Peng–Robinson cubic state equation with the van der Waals mixing rule (PR-vdW2) adequately described the experimentally observed trends.

Visualization of Mass Transfer during Droplet Formation

AbstractThe impact of mass transfer in liquid‐liquid extraction during droplet formation in a quiescent continuous phase was investigated. The impact of droplet size, concentration, and formation rate on a hanging droplet was analyzed via laser induced fluorescence (LIF) using rhodamine 6G as tracer in the system of toluene and acetone in water. The droplet formation rate has a major impact on mass transfer and the mixing pattern inside the droplet. Very fast mass transfer induced by Marangoni convection was visualized at a high local resolution independently of concentration and formation rate.

Quaternary polymeric coatings as alternative to minimize the use of single solvent: Poly(methyl methacrylate) – ethylbenzene – toluene – acetone system

A gravimetric study of a quaternary polymer system of the poly(methyl methacrylate)-ethylbenzene-toluene-acetone coatings has been carried out. The effects of the coating parameters, namely, initial thickness and coating composition have been studied. The evolution of the residual solvent, average concentrations of polymers and solvents, and coating thickness of the quaternary coating system have been compared with that of the binary and ternary coatings. The results indicate that the amount of any toxic or costly solvents can be reduced to a significant extent in quaternary coatings.

Comparison of Phenolic Contents and Biological Potential of Different Polar Extracts of Micromeria graeca, from Algeria

Background: Micromeria species are rich in bioactive compounds such as phenolics which have several medicinal properties. Different solvents are used for extraction of these substances from natural products and solvent type has a major importance in extraction efficiency. In this context, three solvent systems of methanol, ethanol and acetone and their mixture at 50% were used to extract the phenolics with biological effects from Micromeria graeca (L.) Benth. ex Rchb. Methods: The total phenolic and flavonoid contents were determined by the Folin-Ciocalteu and aluminium chloride methods, respectively. The antioxidant capacity of the extracts was evaluated using three different assays. The antifungal capacity against the two strains Candida albicans and Aspergillus niger by using the method of diffusion on disc was also carried out. Results: The 50% acetonic extract gave a better rate of extraction which is 14.4% and presents the highest contents in total phenolics and flavonoids which are of 46.7 ± 2.3 mg gallic acid equivalent /g dry matter and 2.4 ± 0.1 mg quercetin equivalent/g dry matter respectively. A better antioxidant activity for the various tests was observed for 50% methanolic and acetonic extracts. The extract of 50% acetone recorded the most important antifungal activity. Conclusion: The findings of this study showed that the extract prepared with the 50% acetone from Micromeria graeca has the highest phenolics content and revealed the best biological activities. So, this study has allowed us to find the suitable solvent for the preparation of the M. graeca extract for several uses.

Molecular identifications in experiments with astronomical ice analogues: new data, old strategies, and the N2 + acetone system

A recent publication on the radiation chemistry and IR spectroscopy of N2 + acetone ices is used to illustrate some of the difficulties encountered in the study of astronomical ice analogues. Concerns and problems are identified and suggestions for their solution are presented, including new infrared (IR) spectra of amorphous ices. The hazards of using peak positions alone for assignments of the IR spectra of irradiated ices are illustrated, and the importance of considering the underlying reaction chemistry is shown. Several experiments are proposed as a way to investigate the behaviour of acetone in cold, extraterrestrial environments. Electronic versions of IR spectra are provided and several new refractive indices of ices are reported.

Investigations into the distribution of neohistamine methylsulfate in the organism of the warm blooded animals following its intragastric administration

The objective - of the present study was to elucidate the specific features of the distribution of neohistamine methylsulfate (proserin) in the organism of the omnivorous warm blooded animals following its intragastric administration. The analytical methods included TLC, HPLC, and UV-spectrophotometry. Neohistamine methylsulfate was administered intrgastrically to the male Wistar rats at a dose equivalent to the triple LD50 dose. The substance of interest was extracted by acetone from the biological matrices of the dead animals and purified by sequential treatment with the relevant solvents and chromatography in a thin layer of the reverse-phase sorbent (C14-C15 bonded phase model) with the elution in the buffer solution (pH 1.98) - acetone (8:2) system. The compound of interest was identified based on the Rf values (obtained by TLC), retention time (in HPLC), and the spectral characteristics. The quantitative determination of the analyte in the biomatrices was performed with the use of UV spectrophotometry. The analytical methods were validated based on the criteria for linearity, selectivity, correctness, and precision as well as detection threshold and results of quantitation. The largest amount of the study compound were determined in the heart (365.2±33.94 mcg/g), spleen (288.6±24.97 mcg/g), kidney (127.6±9.33 mcg/g), and the gastric walls (124.6±12.17 mcg/g) of the experimental animals.

Enhancing the Bioavailability of a Natural Product Curcumin to increase the Therapeutic Efficacy by a Novel Formulation Technology

Curcumin is found in the rhizome of Curcuma longa. It exhibits various biological activities like anti-cancer, anti-inflammatory, anti-viral, anti-bacterial, anti-oxidant and nematocidal activities. Due to its poor solubility there is a need to formulate this curcumin for better bioavailability. Curcumin was extracted by acetone using soxhlet apparatus and evaporated by means of vacuum rotary evaporator. The presence of curcumin was confirmed by differential scanning calorimetry. Nanosuspension was prepared by bottom up method using acetone and water solvent system. Stabilizers were added under optimized conditions in order to achieve suitable quality of nanosuspension. Then it was analyzed using particle size and zeta potential analyzers for acceptable quality. Pharmacokinetic property and bioavailability are important phenomena that determine the suitability of formulation in therapeutic application. Hence, a study was performed for the prepared nanosuspension formulation. There were two groups of animals considered. One for the formulated curcumin another for non-formulated raw curcumin which served as control. Animals were administrated orally once with 250 mg /kg body weight of respective test drugs and blood samples were collected every 30 min till 180 min. Curcumin in the samples were quantified by HPLC. The Area Under the Concentration time curve (AUC) was drawn and evaluated statistically using ‘t’ test for significant improvement in bioavailability of formulation. Results showed that there is a significant (P< 0.05) improvement in bioavailability and specific pharmacokinetic property for the prepared formulation.

The study of fenspiride: goals and objectives for chemical and toxicological studies

The purpose of this work is to study fenspiride for the purposes and tasks of chemical and toxicological research. The technique of chemical-toxicological study of fenspiride in urine by preliminary and confirming methods is proposed. The authors proposed a method of thin - layer chromatography in the solvent system of acetone - 25% ammonia solution (9:1) in a preliminary study of fenspiride. The Rf value of fenspiride is 0.80±0.02. The degree of extraction when used as an extractant mixture of chloroform-propanol (9:1) is 28.1±1.4% The conditions for identification of fenspiride by gas chromatography-mass spectrometry (fenspiride retention time 11.1±0.1 minutes), followed by quantitative determination of the analyte, are proposed as a confirming method. The conditions for qualitative (retention time of fenspiride 8.1±0.1 minutes) and quantitative determination of fenspiride by high-performance liquid chromatography are proposed.

Experimental Study of Vapor–Liquid Equilibrium Data for Acetone + Methanol + 1-Methyl-3-octylimidazolium Thiocyanate

An experimental study on the isobaric vapor–liquid equilibria for the ternary system of acetone + methanol + 1-methyl-3-octylimidazolium thiocyanate ([Omim][SCN]) as well as the two acetone + ionic liquid (IL) and methanol + IL binary systems was performed at 100 kPa using a recirculating still (VLE 602 Fischer apparatus). A low IL mole fraction of 0.027 was found to be sufficient break the azeotrope due to the high and specific interactions with acetone and methanol. The nonrandom two-liquid model was used to represent the experimental data. The results are compared with those in the literature for the same mixed solvent system using other ILs.

Densities, viscosities, and refractive indices of binary and ternary mixtures of methanol, acetone, and chloroform at temperatures from (298.15–318.15) K and ambient pressure

Densities, viscosities, and refractive indices of binary and ternary liquid systems of methanol, acetone, and chloroform at temperatures from)298.15–318.15(K and ambient pressure were measured. In this regard, it should be stressed that the measurements covered the whole composition range of the components in the binary and the ternary systems. In addition, the experimental data have been utilized in order to extract some derived properties like excess molar volume (VE), viscosity deviation (Δη), and refractive index deviation (ΔnD). To correlate the aforementioned derived properties, the well-known Redlich-Kister and Cibulka equations were applied on the binary and ternary mixtures, respectively. Consequently, the control parameters, as well as the corresponding standard deviations, were completely reported. Moreover, for further validation, the McAllister three-body interaction model for kinematic viscosity and Grunberg-Nissan model for dynamic viscosity were examined and the results were thoroughly compatible with the Redlich-Kister polynomial equation. By using the derived properties, the nature of the intermolecular interactions and the hydrogen bond between solvents in the binary and ternary mixtures were discussed and the results are satisfying in terms of matching to the theoretical models.

Effect of Ionic Liquids on the Isobaric Vapor-Liquid Equilibrium Behavior of Acetone-Chloroform

Isobaric vapor-liquid equilibrium (VLE) data of the ternary system acetone + chloroform + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) or 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]) were obtained at 101.3 kPa. Results indicated that the addition of [MMIM][DMP] or [EMIM][DEP] could eliminate the azeotropic point of the binary system of acetone + chloroform when the mole fraction of ionic liquids (ILs) was above 0.15. Besides, the experimental data could be well correlated by the nonrandom two-liquid (NRTL) model. The structures as well as interactions between molecular solvents (acetone, chloroform) and the ion pairs ([MMIM][DMP], [EMIM][DEP]) were studied by quantum chemical calculations. The result indicated that the interaction energies (ΔE) follow the order of ΔE(acetone + [EMIM][DEP]) &gt; ΔE(acetone + [MMIM][DMP]) &gt; ΔE(chloroform + [EMIM][DEP]) ≈ ΔE(chloroform + [MMIM][DMP]), and chloroform had stronger affinity to ionic liquids than acetone.

Isobaric Vapor–Liquid Equilibrium Data for the Acetone + Hexamethyl Disiloxane + Ethyl Acetate Ternary System at 101.3 kPa: Determination and Correlation

Vapor–liquid equilibrium (VLE) data for the binary system of acetone (1) + hexamethyl disiloxane (HMDSO, 2) and the ternary system of acetone (1) + HMDSO (2) + ethyl acetate (EAC, 3) were obtained ...

Extractive Distillation of Acetone – Methanol Mixture using 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate

Acetone and methanol are organic solvents widely used in industry. Acetone with methanol forms a homogeneous minimum-boiling azeotrope which is not separable by conventional distillation processes. A common method for its separation is the extractive distillation in the presence of a selective solvent (such as water). In this paper, the use of an ionic liquid (1-ethyl-3-methylimidazolium trifluoro methanesulfonate [Emim][triflate]) for acetone–methanol separation by extractive distillation was designed. The aim of the design calculation was to obtain acetone with the purity of 99.5 mol % and methanol with the purity of above 99.0 mol %. Calculations were carried out in a proprietary program constructed in Matlab® by solving a set of material balances at individual theoretical stages of the distillation column combined with the vapor–liquid equilibrium (VLE) of the ternary system acetone–methanol–[Emim][triflate]. For the description of VLE of the above mentioned system, the NRTL equation was used. Several optimization cycles were done resulting in optimal parameters of the extractive distillation column (number of theoretical stages, solvent consumption, reflux ratio and position of the feed stage) in regard to the required purity of products (acetone and methanol). Regeneration of ionic liquid was provided by evaporation at the low pressure of 20 kPa. The heat and cooling consumption duties of the designed separation process were analyzed. Regeneration of the ionic liquid is energy-demanding compared to the separation of acetone–methanol in an extractive distillation column. The heat consumption is only 11 % of the heat used up by the whole separation process.

Absorbent Filaments from Cellulose Nanofibril Hydrogels through Continuous Coaxial Wet Spinning.

A continuous and scalable method for the wet spinning of cellulose nanofibrils (CNFs) is introduced in a core/shell configuration. Control on the interfacial interactions was possible by the choice of the shell material and coagulant, as demonstrated here with guar gum (GG) and cellulose acetate (CA). Upon coagulation in acetone, ethanol, or water, GG and CA formed supporting polymer shells that interacted to different degrees with the CNF core. Coagulation rate was shown to markedly influence the CNF orientation in the filament and, as a result, its mechanical strength. The fastest coagulation noted for the CNF/GG core/shell system in acetone led to an orientation index of ∼0.55 (Herman’s orientation parameter of 0.40), Young’s modulus of ∼2.1 GPa, a tensile strength of ∼70 MPa, and a tenacity of ∼8 cN/tex. The system that underwent the slowest coagulation rate (CNF/GG in ethanol) displayed a limited CNF orientation but achieved an intermediate level of mechanical resistance, owing to the strong core/shell interfacial affinity. By using CA as the supporting shell, it was possible to spin CNF into filaments with high water absorption capacity (43 g water/g dry filament). This was explained by the fact that water (used as the coagulant for CA) limited the densification of the CNF core structure, yielding filaments with high accessible area and pore density.

Comparison of magnetic field effect and exciplex luminescence in pyrene-N,N,dimethylaniline system in acetone and methanol: Anomalous behavior in alcohols

Steady state magnetic field effect (MFE) on pyrene/di-methyl-aniline exciplex luminescence has been studied in various concentrations of pyrene in acetone and methanol. Photo-induced electron transfer in this system generates radical ion pairs undergoing geminate, non-geminate as well as bulk recombination. It has been observed that MFE in acetone is always greater than that in methanol for identical pyrene concentration. However the exciplex fluorescence yield is always greater in methanol than that in acetone. The data and non-typical behavior of alcoholic solvents with respect to the variation of MFE with permittivity has been explained on the basis of a phenomenological model.

Regioselective biomimetic oxidation of halogenated resveratrol for the synthesis of (±)-ε-viniferin and its analogues

FeCl3·6H2O-promoted biomimetic oxidations of 3,5-dihalogeno-resveratrol in different acetone systems produced several coupling intermediates bearing distinct dimeric skeletons with moderate yields. The subsequent deprotection reactions of brominated coupling products achieved the efficient synthesis of natural products (±)-ε-viniferin, (±)-ampelosin B, and (±)-gnetins F, as well as an unnatural oligostilbene. The coupling mechanisms for the formation of different dimeric structures were also proposed.

Finite-Size Effects of Binary Mutual Diffusion Coefficients from Molecular Dynamics.

Molecular dynamics simulations were performed for the prediction of the finite-size effects of Maxwell-Stefan diffusion coefficients of molecular mixtures and a wide variety of binary Lennard–Jones systems. A strong dependency of computed diffusivities on the system size was observed. Computed diffusivities were found to increase with the number of molecules. We propose a correction for the extrapolation of Maxwell–Stefan diffusion coefficients to the thermodynamic limit, based on the study by Yeh and Hummer (J. Phys. Chem. B, 2004, 108, 15873−15879). The proposed correction is a function of the viscosity of the system, the size of the simulation box, and the thermodynamic factor, which is a measure for the nonideality of the mixture. Verification is carried out for more than 200 distinct binary Lennard–Jones systems, as well as 9 binary systems of methanol, water, ethanol, acetone, methylamine, and carbon tetrachloride. Significant deviations between finite-size Maxwell–Stefan diffusivities and the corresponding diffusivities at the thermodynamic limit were found for mixtures close to demixing. In these cases, the finite-size correction can be even larger than the simulated (finite-size) Maxwell–Stefan diffusivity. Our results show that considering these finite-size effects is crucial and that the suggested correction allows for reliable computations.

Effect of Solvent on Conversion and Selectivity during the Selective Oxidation of Cyclohexane by Nano-V2O5/Ti Membrane Electrode

An electrocatalytic membrane reactor (ECMR) with nano-V2O5 loading porous Ti electrode (V2O5/Ti) as an anode was conducted to the selective partial oxidation of cyclohexane (CHA). The ternary phase diagram of CHA, H2O and solvents was determined. The effect of the solvent system on the conversion rate of CHA and selectivity toward cyclohexanone (K) and cyclohexanol (A) during the selective oxidation of CHA was explored. Cyclic voltammetry (CV) and electron spin resonance (ESR) were employed to monitor the electrochemical behavior of CHA-H2O-solvent (acetone and acetic acid) system. Response surface methodology (RSM) was used to optimize the operating parameters of ECMR. Results showed that the conversion of CHA improved with an increasing solvent polarity. The selectivity to K was related to solvent solubility parameter. 16.8% conversion of CHA, 90.2% selectivity to K and 99.9% selectivity to KA oil were obtained from the reaction system with acetone as solvent and acetic acid as co-solvent (CHA concentration 20 mmol L−1). In particular, acetic acid promoted the production of hydroxyl radicals which played a critical role in the selective oxidation of CHA by ECMR.

Isobaric vapor-liquid equilibrium for acetone + methanol system containing different ionic liquids at 101.3 kPa

In order to enhance the separation ability of ionic liquid (IL) in acetone + methanol azeotropic mixture, the isobaric vapor-liquid equilibrium (VLE) data for the ternary systems of acetone + methanol + IL (1-propyl-3-methylimidazolium bromide [PMIM]Br, 1-allyl-3-methylimidazolium bromide [AMIM]Br or 1-allyl-3-methylimidazolium chloride [AMIM]Cl) were measured at 101.3 kPa. The influences of different alkyl side chains or anions on the separation efficiency of IL were studied. The azeotropic point of the binary system is pulled up with the increase of IL content. The azeotropy is completely eliminated when IL content reaches a certain value. The separation efficiency of the three ILs follows the order: [AMIM]Cl > [AMIM]Br > [PMIM]Br. The experimental VLE data are well correlated by the nonrandom two-liquid (NRTL) model.