Mole Fraction Of Solvent Research Articles

Solubility measurement, molecular simulations, Hansen solubility parameter and thermodynamic properties of isophthalic acid in binary solvents at 283.15–323.15 K

The solubility of isophthalic acid (IPA) in four different binary solvent systems (water + methanol, water + ethanol, water + 1-propanol, and water + isopropanol) was measured by the gravimetric method at atmospheric pressure from 283.15 K to 323.15 K. Under certain solvent compositions, the solubility of IPA increased with increasing temperature. The trend of solubility under isothermal conditions setting differs as the mole fraction of organic solvent increases. The solubility of IPA in water + methanol and water + ethanol systems increased with the mole fraction of methanol or ethanol. In the system of water + 1-propanol and water + isopropanol, as the mole fraction of organic solvent increased, the solubility of IPA increased firstly and then decreased gradually. The Hansen solubility parameters of IPA and selected solvents were analyzed, the analysis showed that the miscibility of IPA with the selected solvent was the result of many factors. Molecular electrostatic potential surface (MEPS) and Hirshfeld surface (HS) analysis were used to investigate the intermolecular interactions. The solubility data were correlated using the Apelblat equation, van't Hoff equation, λh equation, and Jouyban–Acree model. Besides, the vant Hoff equation was employed to analyze the apparent thermodynamic properties of dissolving process including the Gibbs energy, enthalpy and entropy. All positive values indicated that the dissolving process of IPA was non-spontaneous, endothermic, and entropy-driven.

A thermodynamic approach to analyzing relative permittivity and solvent mole fraction models, and application to SN1 reactions.

The standard methods for analyzing solvent effects on chemical reactions largely include linear free energy relations that relate kinetic and spectroscopic terms to solvent interactive parameters. The number of these parameters has grown over the years in order to make linear free energy techniques more accurate and cover a wider range of reaction systems. However, even with the myriad of parameters, the details of specific reaction systems make the application of these techniques sometimes unreliable. On the other hand, a thermodynamic approach provides a more precise analysis, and has proven particularly useful for reactions in multi-component solvent systems. In this article we present the mathematical formalism for relating the activation free energy to the bulk thermodynamic properties for a binary (cosolvent) system. We then use this thermodynamic approach, coupled with selected solvent models, to analyze the hydrolysis rates of tert-butyl chloride in the acetonitrile/water solvent system under iso-mole fraction, isodielectric, and isothermal conditions. These analyses allow us to differentiate and quantify bulk electrostatic effects and the effects of close-range solute-solvent interactions.

Thermodynamic functions of succinic acid in acetone–water binary mixtures based on computation of KI & KII constants

Succinic acid is commonly used in various chemical, pharmaceutical, environmental and industrial activities and its reactivity is principally determined by the pK(I & II) values. Therefore, the dissociation constants of succinic acid have been determined in this study on the basis of emf measurements in both different acetone mole fractions and temperature range. The pK(I or II) values of the studied acids in acetone aqueous media were found higher than those obtained in other organic aqueous media with the same conditions (temperature and mole fraction of solvent). Moreover, (KI/KII) in 40 wt% acetone–water mixture was identified to follow succinic acid < malic acid < malonic acid < maleic acid owing to the stabilization of intramolecular hydrogen bonding. The free energy of transfer (ΔG0I or II) for succinic acid was increased with the increasing of pKI or pKII values due to the decrease in relative permittivity (εr) via increment of the acetone fraction in the aqueous medium. The trend of ΔS°I value among the studied acids were found to follow maleic < malic < succinic < malonic. ΔS°II values were characterized lower than ΔS°I due to possible solvent interactions with the acid anion (L2-). Therefore, ΔH°II values of the second dissociation process were identified lower than ΔH°I to favor an exothermic reaction.

Performance of Some Novel Mixed Solvents as Entrainers for Separation of Water and Acetonitrile

Performance of some novel mixed solvents as entrainers was tested for acetonitrile dehydration by extractive distillation. The mixed solvents are composed of ethylene glycol (EG) and choline chloride (ChCl) (EG + ChCl 8:1, EG + ChCl 4:1, EG + ChCl 2:1, and EG + ChCl 4:3), ethylene glycol (EG) and glycerol (EG + glycerol 1:1, EG + glycerol 1:2, EG + glycerol 1:4, and EG + glycerol 1:6), and dimethyl sulfoxide (DMSO) and ChCl (DMSO + ChCl 14:1). Isobaric vapor–liquid equilibrium (VLE) data were measured at 101.3 kPa and at a solvent-free acetonitrile mole fraction of 0.95 for the quaternary systems of water + acetonitrile + EG + ChCl, water + acetonitrile + EG + glycerol, and water + acetonitrile + DMSO + ChCl and for the ternary system of water + acetonitrile + DMSO. The NRTL equation was used for the correlation of the experimental VLE data. For all the three quaternary systems and one ternary system, the mean absolute deviations of equilibrium temperature were no more than 0.33 K, and the mean absolute deviations of water and acetonitrile vapor phase mole fractions were no more than 0.0026 and 0.0047, respectively. The mixed solvent EG + ChCl 4:3, which is also a deep eutectic solvent, showed favorable solvent performance. The azeotrope of water + acetonitrile can be removed at a solvent mass fraction of 0.212 or a solvent mole fraction of 0.104. This amount is less than that of EG (0.367 in mass fraction and 0.227 in mole fraction), EG + glycerol 1:6 (0.341 in mass fraction and 0.195 in mole fraction), and DMSO + ChCl 14:1 (0.266 in mass fraction and 0.153 in mole fraction).

Direct Correlation of the Salt-Reduced Diffusivities of Organic Solvents with the Solvent's Mole Fraction.

Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in organic solvents (especially propylene carbonate) has demonstrated extraordinary pseudocapacitive performance as an electrolyte in the supercapacitor configuration ( Nat. Energy 2019, 4, 241-248). However, the influence of the solvated ions on the diffusivity of the solvent molecules is yet to be understood. We examine the impact of LiTFSI on the diffusivity in five organic solvents: acetonitrile (ACN), tetrahydrofuran (THF), methanol (MeOH), dimethyl sulfoxide (DMSO), and propylene carbonate (PC) using a combination of neutron scattering, conductivity measurements, and molecular dynamics simulations. The extent of the diffusivity reduction in the concentration regime of ≤1 M directly correlates with the solvent mole fraction at which the solvation shells around Li+ ions are of similar size in all the solvents, resulting in a universal ∼50% reduction in the solvent diffusivity. These results provide guidance for formulation of the new electrolytes to enhance the performance of energy storage devices.

Solubility determination and prediction for FOX-7 in three binary solvents at different temperatures

ABSTRACT The solid–liquid equilibrium and thermodynamic properties of FOX-7 in three binary mixed solvents (N-methyl pyrrolidone-water, N,N-dimethylacetamide-water and 1,4-Butyrolactone-water) are studied by focused beam reflectance measurement (FBRM) dynamic detection method and the solubility is predicted by conductor-like screening model for real solvents (COSMO-RS) under atmospheric pressure from 298.15 to 343.15 K. The results show that the solubility of FOX-7 increase with the increasing temperature and the mole fraction of N-methyl pyrrolidone, N,N-dimethylacetamide and 1,4-Butyrolactone. The solubility data can be well correlated by Apelblat, van’t Hoff and Yaws equation. The data of hybrid thermodynamic parameters (including the hybrid enthalpy, entropy, and Gibbs energy) show that the dissolution process is endothermic, non-spontaneous and enthalpy driven. In addition, COSMO-RS can accurately predict the increasing trend of solubility with increasing of temperature and mole fraction of solvent. However, the COSMO-RS overestimates solubility in three binary solvents except for x NMP = 0.1575, the average mean squared quadratic error becomes larger with an increasing mole fraction of water. Solubility data and thermodynamic parameters can lay a foundation for the crystallization and spheroidization modification of FOX-7.

Ultrasonic characterisation of the binary mixture of 2,3-dichloroaniline with methanol and ethanol

ABSTRACT The present work focuses on the ultrasonic characterisation of the binary mixture having constituent liquids, 2,3-dichloroaniline and methanol/ethanol, by measuring their density, viscosity, ultrasonic velocity and estimating thermo-physical parameters at 25°C. The density, viscosity, ultrasonic velocity, acoustic impedance and relative association decay, while compressibility and free length increase with the increase in mole fraction of solvent in the present binary mixture. An anomalous change is received in excess molar volume, free volume, thermal relaxation time, Gibbs free energy and ultrasonic absorption up to 80% solvent mole fraction. The analysis reveals that the binary mixture 2,3-DCA+ methanol has a good intermolecular interaction strength, and is more structural and less corrosive than 2,3-DCA+ ethanol due to the formation of excess hydrogen bonding at 70% solvent mole fraction.

The significance of operating parameters on electromagnetic-solvent bitumen recovery process

Current thermal bitumen recovery processes are highly vulnerable to the low oil price environments. Solvents-aided processes could be a promising option over Steam Assisted Gravity Drainage (SAGD), with the potential for lowered initial capital investment and reduced operating costs. Enhanced Solvent Extraction Incorporating Electromagnetic Heating (ESEIEH®) technology is a novel process where electromagnetic waves and hydrocarbon solvents are employed for bitumen recovery.This study examines the significance of operating parameters on the electromagnetic-solvent process when the injected solvent is either pure propane or pure butane. The effect of several parameters, including operating pressure and applied power on various response surface models, were examined using Design of Experiment and multivariate regression analysis. Results show that the operating pressure is the main governing factor for the selection of the solvent type, while other parameters such as applied power are less significant. Generally, it is recommended to operate the process at native reservoir pressure to minimize the risk of loss of expensive solvents into the thief zones.Lack of reservoir containment (leakiness) is another important factor in the process design, especially when prescribing an operating pressure regime considerably different than that of the surrounding impairments. Due to a wide variation of the in-situ bitumen viscosity in different oil sands reservoirs, each bitumen type requires a different solvent mole fraction to mobilize the bitumen. For the type of bitumen used in this study, the optimum pressure range for butane was found to be around 800–1000 kPa, and for propane injection, around 2400–2600 kPa.

Ultrasonic characterization of binary mixture of 2,3-dichloroaniline and polyethylene glycols

The present study is focused on the ultrasonic characterization of binary mixture having constituent liquids 2,3-dichloroaniline as solute and polyethylene glycols (PEGs) with average molecular weight 200, 400 and 600 as solvent by measurement of density, viscosity, ultrasonic velocity and estimation of thermo-physical parameters at 27 °C and atmospheric pressure 100.3 kPa. The density and acoustic impedance are received to decay while viscosity, ultrasonic velocity, adiabatic compressibility, free length, internal pressure, thermal relaxation time, Gibbs free energy and ultrasonic absorption are found to enhance with an increase in mole fraction of solvents in synthesized binary mixtures The analysis of measured and estimated parameters reveal that the molecular interaction, structural ordering and stability of binary mixture shall enhance with increase in molar mass/mole fraction of PEGs. The ultrasonic absorption is found to be predominantly affected by viscosity. The present study is useful in chemical/pharmaceutical industries and further investigation.

Physico-Chemical Properties of Binary Mixture of 2,3-Dichloroaniline and Carbon Tetrachloride at 300 K

The physico-chemical properties of binary mixture of 2,3-dichloroaniline (2,3-DCA) and carbon tetrachloride (CCl4) have been studied in the present work by the measurement of density, viscosity, ultrasonic velocity and estimation of thermo-physical parameters at 300 K. The density, compressibility, free length, relative association and free volume were found to increase while viscosity, ultrasonic velocity, acoustic impedance and internal pressure were received to decay with an increase in mole fraction of solvent in the binary mixture. The thermal relaxation time and Gibb’s free energy were found to decay with a slow rate up to 50% mole fraction of the solvent, after that these quantities decay very fast in chosen binary mixture. The ultrasonic absorption was also found to increase slowly up to 50% mole fraction of solvent and after that a fast decay was observed in the present binary mixture. The molecular interaction, structural ordering, stability and related features of the prepared binary mixture were also analyzed based on measured and estimated parameters.

Solubility and thermodynamic properties of FOX-7 in four binary mixed solvents from T = 298.15 to 333.15 K

The solubility of 1,1-diamino-2,2-dinitroethylene (FOX-7) in four binary mixed solvents (Dimethyl sulfoxide+Acetonitrile, Cyclohexanone, 1,2-Dichloroethane, Ethyl acetate) was measured by a laser dynamic method over the temperature range from 298.15 K to 333.15 K under 0.1 MPa. Experimental results showed that the solubility increases monotonously as the temperature increases at a given solvent composition or increases with the increasing of mole fraction of good solvent (Dimethyl sulfoxide) in binary mixed solvents, whereas there exists a maximum solubility value in Dimethyl sulfoxide+ Cyclohexanone system. Solubility data were well correlated by the Apelblat equation, van't Hoff equation, general single model (GSM) and modified Jouyban-Acree model, and the Apelblat equation achieved the best fitting results. Moreover, the thermodynamic properties of FOX-7 dissolution process in the investigated mixed solvents, including standard dissolution enthalpy, standard dissolution entropy and standard Gibbs free energy, were calculated by the van't Hoff and the Gibbs equations. The results demonstrate that the dissolution of FOX-7 is a non-spontaneous and endothermic process. The solubility data, correlation models, and thermodynamics properties presented in this study would provide essential support for the further research of crystallization and spheroidization of FOX-7.

Solubility Measurements and Thermodynamic Properties of Sorbic Acid in Binary Solvent Mixtures of (Ethanol, 1-Propanol or 2-Propanol + Water) from 283.15 to 323.15 K

The solubility data of sorbic acid in binary systems of (ethanol + water), (1-propanol + water) and (2-propanol + water) were measured from 283.15 to 323.15 K using the static equilibrium method under atmospheric pressure. It was found that the solubility of sorbic acid in the three binary solvent systems increased with increasing temperature as well as increasing initial mole fraction of organic solvent in these systems. The van’t Hoff–Jouyban–Acree model, the modified Apelblat–Jouyban–Acree model and the CNIBS/R-K model were proposed for correlating the experimental solubility values in various solution systems. Furthermore, the dissolution thermodynamic properties of Gibbs energy change (ΔsolGo), molar enthalpy change (ΔsolHo) and molar entropy change (ΔsolSo) were calculated from the experimental solubility data, using the van’t Hoff equation. The positive values of ΔsolGo, ΔsolHo and ΔsolSo indicate that these dissolution processes of sorbic acid in the solvents studied were all endothermic and entropically favorable. In addition, the change of dissolution enthalpy was the main contributor to the positive value of the molar Gibbs energy of the dissolution process. The experimental solubility and the models used in this work would be conducive to purifying sorbic acid from its crude mixtures.

Rotational diffusion dynamics of Alexa flour dyes in aqueous organic environment

The rotational reorientation times of three dye probes namely Alexa fluor-350 (neutral but polar), Alexa fluor-430 (monoanion) and Alexa fluor-488 (dianion) were determined in series of binary mixtures of DMSO-water, DMA-water, and 2-propanol-water. All the three series of mixtures show bivalued profile for viscosity as a function of mole fraction of organic solvent in water. The dielectric properties such as dielectric constant (ε) and Debye dielectric relaxation time (τD) of solutions change considerably across the composition range. The variation of rotational reorientation time (τr) with viscosity (η) for all the probes is studied. Alexa fluor 350 and alexa fluor 488 show hook type profile in all the three series of aqueous mixtures with rotational reorientation time (τr) being longer in organic solvent rich zone compared to water rich zone mainly due to dielectric friction and hydrogen bonding. Alexa fluor 430 shows hook type profile in 2-propanol-water mixtures similar to other two probes but in DMSO-water and DMA-water it has almost linear profile as rotational reorientation dynamics is almost similar in both organic solvent rich zone and water rich zone. The hook type profiles obtained suggest the importance of local molecular structure of binary mixture and its interaction with probe. Results obtained are discussed in light of SED (hydrodynamic) theory, dielectric friction theories and friction due to hydrogen bonding.

Solubility and dissolution thermodynamic properties of L-carnosine in binary solvent mixtures

Thermodynamic data are the basis for design of crystallization process and control of crystal morphology and polymorph. In this work, solubility data of L-carnosine in different binary solvent mixtures, including water + (methanol, isopropanol or acetone), were determined in temperatures ranging from 288.05 K to 323.15 K by static method under atmospheric pressure. It was found that the solubility data of L-carnosine decrease apparently with the increasing of the mole fraction of organic solvent in binary solvent mixtures and increase with the rising of temperature. In addition, the experimental solubility data were correlated and analyzed by the modified Apelblat equation, the NRTL model and the Jouyban–Acree model to extend the applicability of the solubility data. Finally, the standard dissolution thermodynamic properties, including Gibbs energy, entropy and enthalpy were calculated and discussed based on the experimental solubility data and Van’t Hoff equation.

Solubility determination and thermodynamic modelling of gliclazide in five binary solvent mixtures

The solubility of gliclazide in five different binary solvent mixtures, (i.e. acetone-water, tetrahydrofuran-water, N, N-dimethylformamide-water, acetone-ethanol, and chloroform-ethanol) was measured in the temperature rang 278.15–318.15 K and at atmospheric pressure by a gravimetric method. The results show that the solubility of gliclazide increases with an increase in temperature and an increase in the mole fraction of nonpolar aprotic solvent. The combined nearly ideal solvent / Redlish-Kister (CNIBS/R-K) model, modified Jouyban-Acree model, non-random two-liquid (NRTL) model, and the Wilson model were selected to correct the solubility data. It was found that, solvent polarity has a critical effect on the solubility of gliclazide. The CNIBS/R-K model, with maximum RAD and RMSD values of 0.0540 and 0.000131, respectively, was found to be the best-fitting model for solubility data correction in the selected binary solvent mixtures. RAD values of all the selected thermodynamic models were <0.0806, that is, these equations produced well fitted results for the solubility data of gliclazide. These experimental data are of great significance for investigation of the crystallization process of gliclazide.

Solid-liquid phase equilibrium of phenylphosphonic acid in three binary solvents: Determination, correlation and molecular simulation

Abstract In this research work, solubility of pyrethroid insecticide phenylphosphonic acid (PPOA) in three binary solvents including methanol (MtOH) + ethyl acetate (EtAC), ethanol (EtOH) + EtAC at (278.15 to 323.15) K and 1,4-dioxane + EtAC at (288.15 to 323.15) K was investigated by laser monitoring method at 0.1 MPa. Solubility of PPOA increased with the increasing temperature while decreased with the increasing mass-fraction of EtAC. The solubility behavior was studied by molecular simulation. The solute-solvent interaction (Einter) suggested that solubility of PPOA increased with values of Einter increasing and there existed the strong interactions between PPOA and most selected binary solvents except 1,4-dioxane + EtAC. The radial distribution function (RDF) between two components of mixed solvent indicated that the tendency to aggregation of two components molecules increased with the increment of corresponding mole fraction of binary solvents. It also confirmed to some extent that the solute – solvent interaction energy would be weaken and the PPOA solubility in binary selected decreased. At the same time, it was found that the hydrogen bond existed in binary solvents namely “MtOH + EtAC and EtOH + EtAC”. So solubility of PPOA resulted from the integrated effect of solute – solvent and solvent – solvent interactions. Moreover, experimental solubility values were correlated by four multi-component activity coefficient models including Wilson, NRTL, Margules and UNIQUAC model. Four thermodynamic functions provided good correlations with solubility values. Furthermore, thermodynamic properties of mixing process were calculated by Wilson equation and corresponding solubility data. Mixing process was entropy-driven in selected solvents and exothermic in most binary solvents except EtAC and 1,4-dioxane (w1 = 0.2016) + EtAC.

Role of solvent properties and composition on the solid-liquid equilibrium of trifloxystrobin and thermodynamic analysis

This paper is to critically analyze the effects of solvent properties and composition on the solubility of trifloxystrobin. The solubility of trifloxystrobin in eight mono-solvents and two binary solvents was determined at temperatures ranging from 283.15 K to 318.15 K. Among the selected mono-solvents, the solubility of trifloxystrobin in alcohols was greater than that in alkanes and obeyed the following order: n-propanol > ethanol > methanol > 2-propanol > n-butanol > n-hexane > n-heptane > n-octane. For the binary solvents, as the mole fraction of good solvent (methanol/ethanol) increased, the solubility of trifloxystrobin increased monotonically at the set temperatures. In addition, the obtained solubility data was correlated with the Apelblat, NRTL, Wilson and Apelblat Jouyban Acree model, and these models were in good agreement with the experimental values. The NRTL model given the results of entropy, enthalpy and Gibbs free energy, which indicated that the dissolution was spontaneous, endothermic and entropically driven. The powder X-ray diffraction patterns proved that there was no polymorphic transformation during the solubility measurement.

Similarity and differences of the thermochemical characteristics of l-glutamine dissolution in aqueous solutions of some acetamides and formamides at T = 298.15 K

The enthalpies of l-glutamine dissolution in an aqueous solution of acetamide, N-methylacetamide, and N, N-dimethylacetamide were determined by the calorimetric method at T = 298.15 K and organic solvent mole fractions up to x2 ~ 0.25. The standard enthalpies of solution (ΔsolH°) and transfer (ΔtrH°) of l-glutamine from water to a mixed solvent as well as the enthalpy coefficients of pairwise interactions (hxy) were calculated. The interrelation between enthalpic characteristics of l-glutamine dissolution (transfer) and the composition of water-organic mixtures was determined. The received thermochemical characteristics of intermolecular interactions of l-glutamine with the molecules of acetamides were compared with the analogous characteristics interactions of l-glutamine with the molecules of formamides (formamide, N-methyformamide, and N, N-dimethylformamide).

Effect of hydrogen bond on solvation dynamics of coumarin153 in cyclohexane-phenol solvent mixtures by time-resolved optical Kerr fluorescence.

Time-resolved optical Kerr fluorescence system was used to investigate time-resolved red-shift of coumarin 153 in different solvent mixtures. The mixtures included four mole fractions of phenol-cyclohexane solvents (0, 0.013, 0.08, and 0.3), and anisole-cyclohexane solvents with the mole fraction of 0.3. The measured time-resolved fluorescence showed that, in the solvent mixtures containing phenol, the time-dependent frequency shift accelerated with the increase in the mole fraction of phenol-cyclohexane mixtures. However, the time-dependent red-shift in the fluorescence was not observed in the anisole-cyclohexane mixture, the solvent polarity could not influence the spectral Stokes shift compared with phenol. The results indicated that coumarin 153 formed an excited hydrogen bond with phenol, and the excited hydrogen bond was strengthened with an increase in the mole fraction of phenol. And, these processes also suggested that the increase in the phenol ratio improves a large number of hydrogen bond formed between phenol and carbonyl group of coumarin 153, the charge distribution will be faster towards lower the free energy of the system due to the stronger dipole moment. Therefore, the corresponding solvation response in phenol-cyclohexane mixtures with higher mole fractions decays very rapidly.

Front Cover: Resin Swelling in Mixed Solvents Analysed using Hansen Solubility Parameter Space (Chem. Eur. J. 19/2019)

3D Hansen solubility space is used to explain why the ability of binary mixtures of two solvents to swell crosslinked resins does not vary linearly with the solvent mole fractions. The cover artwork, which is loosely based on the famous 1979 poster for the film Alien, shows a series of small eggs at the bottom representing unswollen resin beads each surrounded by a single solvent. The centre of the image shows a much larger egg representing a swollen resin bead, now surrounded by a mixture of two solvents. Coming off the egg is a tripeptide representing the solid-phase peptide synthesis reported in the paper. More information can be found in the Full Paper by M. North et al. on page 4951.