Journal of Chemical & Engineering Data最新文献

This article reports the results of thermodynamic modeling of activity and osmotic coefficients of the quaternary system of mixed NaCl + RbCl in mixed CH₃OH + H₂O solvent based on the potentiometric method at 298.15 ± 0.05 K. By employing the EMF method without the liquid junction comprising chloride-selective and sodium-selective electrodes, the measurements were accomplished over the concentration range from 0.0005 up to 2.4941 mol·kg^–1 for different series of salt molal ratios (r = m_NaCl/m_RbCl = 100, 150, 200, and 250) with various alcohol mass percentages in water (w = 0.0, 0.10, 0.20, 0.30, and 0.40). The experimental results were modeled and interpreted in terms of the Pitzer ion-interaction approach. Exploiting the Pitzer model permitted the optimization and determination of the unknown Pitzer mixing parameters (θ_NaRb and ψ_NaRbCl) for each series of the investigated system. Eventually, having evaluated these parameters of the Pitzer model, it was possible to compute the activity coefficients of the constituent’s electrolyte, the excess Gibbs energy, and osmotic coefficients for various fractions of methanol in water for mixtures of sodium and rubidium electrolytes with common anion. The results of modeling for the system under consideration were surprisingly in good agreement with an empirical rule by Harned for the second electrolyte.

Two betaine-based deep eutectic solvents (DESs), betaine/glycerol [1:2] and betaine/ethylene glycol [1:3], were used in separation processes encountered in the petroleum industry. Liquid–liquid equilibrium of six ternary systems {thiophene + betaine/glycerol [1:2] or betaine/ethylene glycol [1:3] + n-heptane}, {pyridine + betaine/glycerol [1:2] or betaine/ethylene glycol [1:3] + n-heptane}, and {toluene + betaine/glycerol [1:2] or betaine/ethylene glycol [1:3] + n-heptane} were measured at 298.15 K under atmospheric pressure. Phase diagrams of the ternary systems were represented by using the COnductor-like Screening MOdel for Real Solvents (COSMO-RS) and Non Random Two-Liquids equation (NRTL) models. In terms of selectivity and capacity values, betaine/ethylene glycol seems to be the most efficient deep eutectic solvent (DES) in this study. Optimal conditions for the separation process of thiophene, pyridine, or toluene from n-heptane were determined using synthetic fluids composed of n-heptane and 5% of thiophene, pyridine, or toluene. In all cases, the optimal conditions for the extraction were observed with a mass ratio m_DES/m_sample = 2 and a temperature fixed at 293.15 K. A fourth stage extraction using betaine/ethylene glycol [1:3] allows to remove 99.7% of pyridine and 57.5% of thiophene.

During Li-ion battery operation, (electro)chemical side reactions occur within the cell that can promote or degrade performance. These complex reactions produce byproducts in the solid, liquid, and gas phases. Studying byproducts in these three phases can help optimize battery lifetimes. To relate the measured gas-phase byproducts to species dissolved in the liquid-phase, equilibrium proprieties such as the Henry’s law constants are required. The present work implements a pressure decay experiment to determine the thermodynamic equilibrium concentrations between the gas and liquid phases for ethylene (C₂H₄) and carbon dioxide (CO₂), which are two gases commonly produced in Li-ion batteries, with an electrolyte of 1.2 M LiPF₆ in 3:7 wt/wt ethylene carbonate/ethyl methyl carbonate and 3 wt % fluoroethylene carbonate (15:25:57:3 wt % total composition). The experimentally measured pressure decay curve is fit to an analytical dissolution model and extrapolated to predict the final pressure at equilibrium. The relationship between the partial pressures and concentration of dissolved gas in electrolyte at equilibrium is then used to determine Henry’s law constants of $k_{C_2{H}_4}=$ 2.0 × 10⁴ kPa for C₂H₄ and k_CO2 = 1.1 × 10⁴ kPa for CO₂. These values are compared to Henry’s law constants predicted from density functional theory and show good agreement within a factor of 3.

To investigate the solution behavior of nicotinic acid (vitamin B₃) in two significant aqueous ionic liquid solutions, viz., BTEAC (benzyltriethylammonium chloride) and BTBAC (benzyltributylammonium chloride), we have studied some physicochemical parameters such as density, viscosity, surface tension, refractive index, and conductivity measurements at concentrations of 0.001, 0.003, and 0.005 mol·kg^–1, as well as at temperatures of 298.15, 303.15, 308.15, and 313.15 K under an atmospheric pressure of 1.013 bar. The limiting apparent molar volumes (φ_V⁰) derived from the Masson equation, the viscosity parameters, A- and B-coefficients, and molar refraction (R_M) from the Lorentz–Lorenz equation are used to criticize the solute–solute and solute–solvent interactions that prevail between vitamin B₃ with aqueous IL solutions. Transfer volumes (Vφ_tr⁰) and interaction parameters (V_AB, V_ABB) are also helpful for the determination of interactions associated with the ternary systems. Conductivity data is also used to explain the nature of interaction in the (vitamin B₃ + aq. ILs) mixtures. Several thermodynamic parameters, such as Δμ₁^0#, Δμ₂^0#, TΔS₂^0#, and ΔH₂^0#, show that there are substantial molecular interactions existing in the studied system. From ¹H NMR, ultraviolet–visible (UV–vis) spectroscopy information data also supported our experimental as well as theoretical findings. Optimization energy calculation by computational analysis using the density functional approach leads to the stability of the molecular assembly of the ternary (vitamin B₃ + IL + H₂O) system at the molecular level to validate the experimental results.

In this paper, the cell potential method is used to determine the activity coefficients of the NaBr–Na₂SO₄–H₂O ternary system at 278.2 and 288.2 K. The cell potentials of NaBr–H₂O solutions are measured using a cell without a liquid junction composed of ion-selective electrodes. According to the measured cell potentials of NaBr-H₂O solutions, the response curve can be obtained by combining the Nernst equation. The measured cell potentials of NaBr–Na₂SO₄–H₂O mixed solutions are combined with the Nernst equation to determine the activity coefficients, and the mixed ion interaction parameters θ_Br,SO4 and ψ_Na,Br,SO4 of the Pitzer model are obtained by applying the activity coefficients and the programming solver. Then, other thermodynamic parameters are calculated using Pitzer equations, such as the activity coefficient of Na₂SO₄ (γ_Na2SO4), the osmotic coefficient ($\mathrm{\Phi }$), water activity (a_w), and excess Gibbs free energy (G^E). In addition, the phase equilibria of the NaBr–Na₂SO₄–H₂O ternary system at 288.2 K were investigated using the isothermal dissolution equilibrium method, and phase equilibrium predictions were made for the NaBr–Na₂SO₄–H₂O ternary system at 278.2 and 288.2 K. The experimental values of the system at 288.2 K are in good accordance with the predictions, and therefore, the fitted parameters have good applicability.

At 298.15, 308.15, and 318.15 K, mutual solubility was experimentally measured under about 0.1 MPa for four systems: benzoic acid + isoniazid + ethanol, 4-aminobenzoic acid + isoniazid + ethanol, benzoic acid + isoniazid + acetonitrile, and 4-aminobenzoic acid + isoniazid + acetonitrile. The measured mutual solubility of these systems was used to generate isothermal cocrystal phase diagrams. An approach of Schreinemaker’s wet residue together with XRD scans was utilized to ratify the solids appeared in these systems, which pertained to isoniazid, 4-aminobenzoic acid, and 2:1 4-aminobenzoic acid-isoniazid cocrystal (mole ratio) for 4-aminobenzoic acid + isoniazid + ethanol/acetonitrile systems and isoniazid, benzoic acid, and 1:1 benzoic acid-isoniazid cocrystal (mole ratio) for benzoic acid + isoniazid + ethanol/acetonitrile systems. There were three cosaturated curves, five crystalline regions, and two cosaturated points in the ternary benzoic acid + isoniazid + ethanol/acetonitrile and 4-aminobenzoic acid + isoniazid + ethanol/acetonitrile systems, respectively. Additionally, using molecular simulation, the hydrogen bond and interaction energy between isoniazid and benzoic acid/4-aminobenzoic acid were discussed.

Comprehensive equations for the thermodynamic properties of aqueous Li₂SO₄ solutions applicable to high temperatures and pressures have been generated by using the literature data for the volumetric properties in conjunction with the osmotic/activity coefficients at 0.1 MPa for temperatures up to 373.15 K and vapor saturation pressures above 373.15 K. The composition dependence has been represented by the equations of Pitzer, which combine a theoretical form and Debye–Hückel terms with empirically evaluated parameters for short-range interactions. In particular, the volume equations have been integrated to yield the osmotic and activity coefficients. The pressure derivatives of the Pitzer ion-interaction parameters of osmotic/activity coefficients provided the values of relative apparent molar enthalpies of this electrolyte solution. The set of equations generated here gives rise to osmotic coefficients, activity coefficients, and relative apparent molar enthalpies of aqueous Li₂SO₄ solutions to 1.0 mol·kg^–1, 40 MPa, and 498.15 K. Analyses of the results provided important information regarding the ion-association behavior of the system under consideration.

In the present work, an assessment of the processes of glycyl-l-alanine solvation is given when the nature of an aqueous–organic mixture changes. For this purpose, the enthalpies of the glycyl-l-alanine dissolution in aqueous solutions of ethanol, 1-propanol, 2-propanol, acetonitrile, 1,4-dioxane, acetone, and dimethyl sulfoxide were measured by isothermal calorimetry at T = 298.15 K. Corresponding enthalpies of solvation (Δ_solvH°) were determined by combining the obtained values (Δ_solH°) with the standard enthalpies (Δ_subH°) of glycyl-l-alanine sublimation. In addition, we derived the enthalpic coefficients of the pairwise interactions (h_xy) between glycyl-L-alanine and organic solvent molecules, as well as the transfer enthalpies (Δ_trH°) from water in admixture with them. A comparative analysis of changes in the transfer enthalpies of glycyl-l-alanine, glycyl-glycine and glycyl-l-tyrosine from water to similar water–organic mixtures is presented. The modified Kamlet–Taft equation was used to quantify the contribution of some physicochemical properties of organic solvents (polarity/polarizability, cohesion energy density, basicity, and acidity) to the energy of intermolecular interactions of glycyl-l-alanine–cosolvent.

The solid–liquid phase equilibriums composed of succinic acid + tebuconazole + ethanol and fumaric acid + tebuconazole + ethanol at 298.15, 313.15, and 323.15 K and benzoic acid + tebuconazole + ethanol at 278.15, 288.15, and 298.15 K under atmospheric pressure were determined using the isothermal saturation method. Nine isothermal phase diagrams for these systems were constructed. The influence of temperature on the crystallization region of a cocrystal was investigated. In addition, interactions between tebuconazole and succinic acid/fumaric acid/benzoic acid were calculated via quantum chemical calculations, together with an independent gradient model based on Hirshfeld partition analysis. The results can be used to explain the cocrystalline behavior of tebuconazole–succinic acid/fumaric acid/benzoic acid cocrystals in ethanol and to make sense of the discovery of tebuconazole cocrystals with organic acids.

This study offers a thorough evaluation of the thermophysical characteristics of 2-ethyl-1-butanol (2E1B) mixed with a series of straight-chain alcohols ranging from 1-propanol to 1-hexanol across 293.15–323.15 K. The work focuses on evaluating the density and viscosity of the above systems. The outcomes reveal that the mixtures exhibit positive deviations in excess molar volume, with a direct correlation with the lengthening of the carbon chain of alkanol. Viscosity deviation is negative from ideal behavior, becoming more pronounced with increasing chain length. This trend suggests the presence of weak intermolecular forces between 2E1B and normal alkanol. Besides, the investigation utilized the Cubic-Plus-Association (CPA) equation to model the binary system density. The equation exhibits a strong correlation with the experimental density, with a maximum discrepancy of only 0.46% observed in the 2E1B + 1-hexanol system. This minimal deviation emphasizes the CPA model’s effectiveness in accurately representing the density measurements.