Journal of Chemical & Engineering Data最新文献

The solubility of 2-cyanoacetamide (2-CA) was ascertained by means of a gravimetric technique in four different kinds of aqueous mixed solvents, specifically water + (methanol (MeOH), ethanol (EtOH), 1-propanol (1-PrOH), or 2-propanol (2-PrOH)). The experiment was conducted between 283.15 and 323.15 K in temperature. The findings show that in all four binary solvent systems, 2-CA becomes more soluble at higher temperatures. The KAT-LSER model was employed to analyze the impact of solute–solvent intermolecular interactions on solubility. In order to simulate the solubility of 2-CA in binary mixed solvents, three thermodynamic models were used. The low values for the average relative deviation (RAD%) (≤1.23, ≤2.20, and ≤3.68) show that the experimental solubility data for 2-CA in the four binary solvent mixtures exhibit strong agreement with the correlated data utilizing the Jouyban–Acree, Jouyban–Acree–van’t Hoff, and Apelblat–Jouyban–Acree models. The thermodynamic properties of the solution were used to calculate the special solvation variables by the use of inverse Kirkwood–Buff integrals. The preferential solvation variables for MeOH/EtOH/1-PrOH/2-PrOH displayed negative values in the MeOH (1) + water (2) mixture, within the range of 0.31 < x₁ < 1, for the EtOH (1) + water (2) mixture with compositions falling between 0.24 < x₁ < 1, for the 1-PrOH (1) + water (2) mixture with compositions within 0.20 < x₁ < 1, and for the 2-PrOH (1) + water (2) mixture within the range of 0.20 < x₁ < 1. This suggests that while alcohol preferentially solvates water molecules in surroundings rich in alcohol, alcohol molecules preferentially solvate 2-CA in mixes rich in water.

The global need for rechargeable batteries has increased significantly, leading to a corresponding rise in demand for lithium. This study explores the use of tetracyanoborate-based ionic liquids (IL) and tributyl phosphate (TBP) for the liquid–liquid extraction of lithium ions (Li⁺) from aqueous sources. The investigation includes comprehensive experimental analyses and modeling with the electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT). The Experimental Section investigates the process conditions for the extraction efficiency of the extraction system. It includes investigations into the best TBP/IL ratio of the TBP/IL extraction agent mixture and the influence of the phase ratio (mass of IL + TBP/mass of the aqueous salt solution) on extraction efficiency. The results proved the synergetic effects of the two extraction agents, IL and TBP, providing maximum efficiency at TBP/IL = 0.85. Li⁺ was almost completely extracted from an aqueous LiCl solution using optimized conditions. The ePC-SAFT modeling approach accounted for the ion-pair-assisted extraction of Li⁺ into the organic phase, enabling the description of the experimental behavior as quantitatively correct. This provided deeper understanding of the thermodynamic behavior within the liquid–liquid extraction system and paves the way for the screening of numerous IL systems for Li⁺ extraction and the prediction of optimal process conditions in the future.

The density ρ and speed of sound u for the binary mixture (1,4-dioxane (1) + chloroform (2)) were measured over the whole composition range of 1,4-dioxane at temperatures T = 295.15, 298.15, 301.15, 304.15, 307.15, 310.15, and 313.15 K and at atmospheric pressure. The experimental data were used to calculate the excess molar volume $V_m^E$, isobaric thermal expansion coefficient α_p, excess isobaric thermal expansion coefficient ${\alpha }_p^E$, excess speed of sound u^E, isentropic compressibility κ_s, excess of isentropic compressibility ${\kappa }_s^E$, intermolecular free-length L_f, the excess intermolecular free-length $L_f^E$, acoustic impedance Z, and the excess acoustic impedance Z^E. It was observed that some parameters, including α_p, κ_s, L_f, and Z decrease with increasing 1,4-dioxane mole fraction, while u is in increase. The physicochemical and acoustical parameters indicate the behavior of molecules as temperature increases. The magnitude of intermolecular interactions among the components of the mixtures reflects the nature of the substances. The excess parameters were fitted by using the Redlich–Kister polynomial equation to obtain coefficients and estimate standard error values. Thermodynamic properties can be used to analyze and understand the nature of molecular interactions between two components in a studied mixture.

The densities (ρ), speeds of sound (u), and viscosities (η) of pure ionic liquid (IL, [EMIM][N(CN)₂]), solvents, iso-butanol (i-BuOH), and tert-butanol (t-BuOH) and of its binary mixtures were experimentally measured using a high-precision vibrating tube densitometer (ρ and u) and an automated falling ball microviscometer (η) as functions of the mole fraction of IL (x₁) at T = 298.15–323.15 K and p = 0.1 MPa. Experimentally measured values of ρ, u, and η were used to evaluate excess/deviation parameters, and these parameters are correlated utilizing the Redlich–Kister polynomial equation. Correlations were also performed for the excess molar volumes (V_m^E) of each binary mixture using the Prigogine–Flory–Patterson equation. Forces of attraction that exist between the ions of IL and IL-solvent mixtures are well discussed. Density functional theory (DFT) was also applied to establish the possible molecular interactions between the ions of IL ([EMIM]⁺and [N(CN)₂]⁻) and the IL-solvent mixtures, revealing interactions at the D3-B3LYP/6–311++G(d,p) level of theory. Moreover, various molecular properties, including structures, frontier molecular orbitals, electrostatic potentials, atomic charges, dipole moments, interaction energies, and reactivity descriptors, were obtained at the same level of theory.

A crucial factor in the development of sustainable crystallization processes is the use of biobased solvents, which, in turn, necessitates a comprehensive understanding of the solubility profiles of solid compounds in biobased solvents. The solubility of timolol maleate (TIM), used to treat glaucoma, was measured in commercial biobased solvents at temperatures ranging from 278.15 to 333.15 K using the polythermal method. Its solubility was determined in eight neat biobased solvents (acetone, 1-butanol, Cyrene, dimethyl isosorbide (DMI), ethanol, 2-methyltetrahydrofuran (2-MeTHF), 2-propanol, and water) and three binary solvent mixtures (ethanol + 2-propanol, ethanol + 2-MeTHF, and ethanol + DMI). It was demonstrated that the solubility of TIM increases with temperature in the pure solvents and solvent mixtures. Furthermore, the solubility of TIM decreases in ethanol with increasing 2-propanol, 2-MeTHF, or DMI content, which may act as antisolvents. The experimental solubility data of TIM in the pure solvents and binary solvent mixtures were correlated using the modified Apelblat, Yaws, and λh equations. The correlated solubility data agree well with the experimental results, indicated by the small relative deviation and average relative deviation (ARD %) values. The correlated and experimentally determined solubility data provide crucial information for the design of sustainable crystallization processes for TIM.

The phase equilibria of the quaternary system KCl–KH₂PO₄–(NH₂)₂CO–H₂O and its ternary subsystem KH₂PO₄–(NH₂)₂CO–H₂O at 303.15 K were studied by the isothermal dissolution equilibrium method, and the phase diagrams were plotted. The equilibrium solid phase was identified by Schreinemaker’s wet residue method and X-ray diffraction (XRD). The ternary subsystem is a simple cosaturated system, the phase diagram contains one saturation point, two univariate curves, and three crystallization regions. A comparison of the phase diagrams of ternary subsystem at different temperatures shows that the cocrystallization region of KH₂PO₄ and (NH₂)₂CO decreases with the increase of temperature. The phase diagram of the quaternary system shows that the system is a simple cosaturated system, including one invariant point, three univariant curves, and three crystallization regions. Based on the Pitzer–H–W model, the lacking particle interaction parameters were regressed using the solubility data of the ternary systems and used to calculate the solubility data. By comparing the experimental value with the calculated value, the results both indicated that the experiment and theoretical calculation have good consistency, and the Pitzer–H–W model is suitable for the electrolyte and neutral molecule solution systems.

In order to efficiently exploit and utilize bromine-rich underground brine resources of China, the quinary system NaBr–KBr–MgBr₂–SrBr₂–H₂O at 273.15 K was studied in detail by the isothermal dissolution equilibrium method. According to phase equilibrium data in the quinary system, the three-dimensional space phase diagram of the quinary system was constructed, and there were two invariant points, seven univariate curves, and five solid-phase crystallization regions NaBr·2H₂O, KBr, SrBr₂·6H₂O, MgBr₂·6H₂O, and KBr·MgBr₂·6H₂O. And three simplified dry salt phase diagrams were drawn for the quinary system under saturation conditions of NaBr·2H₂O, KBr and SrBr₂·6H₂O. Furthermore, the solubilities of salts in the quinary systems NaBr–KBr–MgBr₂–SrBr₂–H₂O at 273.15 K (saturated with NaBr·2H₂O, KBr, and SrBr₂·6H₂O) were theoretically predicted by using the Pitzer model, and the calculated solubilities were in good agreement with the experimental values on the whole.

Ionic liquids with the dicyanamide anion, namely, with 1-alkyl-imidazolium cations, have been receiving attention recently due to their potential applications. The utilization of these liquids as heat transfer fluids, specifically in small heat exchangers and microchannels for microprocessor cooling, is presently deemed highly feasible, as it can be both more efficient and environmentally acceptable. The design of a heat transfer equipment that makes use of fluids requires knowledge of their thermophysical properties. In this regard, dispersions of nanoparticles have been extensively studied in recent years to improve thermal conductivity or obtain desirable optical properties. IoNanofluids is what we have taken to name the result of such dispersions in ionic liquids. In this paper, we report measurements of the thermal conductivity and viscosity of the IoNanofluid of 1-ethyl-3-methylimidazolium dicyanamide, [C₂mim][N(CN)₂], with 0.5% mass fraction of TiO₂ nanoparticles (diameter 20 nm) in the temperature range (293 < T/K < 343), at P = 0.1 MPa. Reasonable enhancements were found for thermal conductivity and viscosity, which were temperature-dependent. The IoNanofluid was found to behave as a non-Newtonian fluid in most of the temperature range studied. A discussion about the possible use of this IoNanofluid as a heat transfer fluid shows that it has very promising properties to be used in heat transfer applications.