Journal of Solution Chemistry最新文献

The impact of water on the physicochemical properties and CO₂ absorption capability of the N-methyldiethanolamine (MDEA) + polyethylene glycol 300 (PEG300) solution was explored. The molar ratio of PEG300 to MDEA was fixed at 0.3734: 0.6266, and the density and viscosity of the aqueous solutions were measured at P = 100.5 kPa and T = (298.15–318.15) K. Based on these measurements, the excess properties of the system were calculated. Meanwhile, spectral analysis confirmed the formation of intermolecular hydrogen bonds among MDEA, PEG300, and H₂O. Building on these findings, the influence of water content on the cyclic CO₂ absorption performance of the H₂O + (PEG300 + MDEA) system was systematically investigated, with particular emphasis on the regeneration behavior at 15 wt% MDEA concentration. Furthermore, the underlying mechanism of the cyclic CO₂ absorption process was elucidated using multiple analytical techniques. These insights provide certain theoretical support for the industrial application of PEG300 + MDEA aqueous systems in CO₂ capture.

Scale deposition in oil/gas/water wells is a critical factor affecting well stability, making targeted selection of descaling agents and their field application parameters crucial for enhancing and sustaining production. Currently, the petroleum industry commonly employs traditional gravimetry to evaluate dissolution rates—an intermittent testing method with discontinuous data acquisition, susceptible to human interference, and incapable of real-time monitoring. This results in insufficient data for dissolution process analysis, leading to significant testing errors and low efficiency. To address these limitations, this study considers the universal phenomenon of real-time volume reduction and buoyancy loss during solid dissolution. By introducing parameters such as “buoyancy-equivalent mass” and “tension-equivalent mass”, a real-time dissolution rate calculation method was established based on dynamic force variations. Furthermore, a real-time scale dissolution rate testing procedure was designed and refined, and a testing platform was constructed. To demonstrate the superiority of the new method, comparative experiments were conducted between this method and the traditional gravimetric method for scale dissolution rate testing, comparing their testing precision and efficiency. The comparative experimental results are as follows: (1) The new method exhibits superior testing precision: Compared to the traditional gravimetric method, its standard deviation and relative standard deviation decreased by 11.3% (3.07% vs. 3.46%) and 25.9% (5.31% vs. 7.17%), respectively; (2) The new method demonstrates higher testing efficiency: Compared to the traditional gravimetric method, it offers better time efficiency (shorter testing duration: 7.3 h vs. 8.5 h), superior resource efficiency (fewer equipment usage instances: 7 times vs. 15 times), and better output efficiency (larger volume of data collected: sampling frequency 1 Hz vs. 1 h⁻¹, a 3600-fold difference). This study proposes a novel real-time scale dissolution rate testing method that addresses the issue of discontinuous data acquisition. The method exhibits enhanced precision and efficiency. It holds great potential for studying the dissolution kinetics of salt scales and significant application value in the precise treatment of long-standing scale issues in oil and gas transportation pipelines.

In this study, the Extended UNIQUAC thermodynamic model for electrolyte solutions was used to calculate the solubility of carbon dioxide in potassium carbonate aqueous solution. Available experimental data were used for determining the model parameters at temperatures of 313.15 K to 393.15 K, different equilibrium pressures (up to 1.2 MPa) and different solution concentrations of 15, 20 and 30 wt%. The value of the unknown parameters of the Extended UNIQUAC model, including the volume parameters, the surface parameters and the interaction energy parameters were optimized by nonlinear optimization method using experimental data available for ternary CO₂–K₂CO₃–H₂O system. The fugacity coefficient in the vapor phase was obtained using Soave–Redlich–Kwong equation of state (SRK-EOS). The results of this study show that the Extended UNIQUAC is a consistent thermodynamic model for representing vapor–liquid equilibrium (VLE) of the CO₂–K₂CO₃–H₂O system and the average absolute relative deviation (AARD) between the experimental and the predicted data was 3.81%.

A polemic is given regarding several of the acoustic properties reported in the published paper by Nain and Chand. The excess sound velocity was found to be based on an incorrect mathematical expression for the density of an ideal solution, and the authors’ calculated numerical values for the excess partial molar isentropic compressions of the individual mixture components were found to be inconsistent with the excess molar isentropic compressions of the binary liquid mixtures. The inconsistencies likely result from incorrect mathematical expressions used to calculate the partial molar isentropic compressions of the individual mixture components.

Phenolic acids, widely present in agro-industrial residues (e.g., olive leaves, rice husk hydrolysate) and plant extracts, are valuable bioactive compounds with antioxidant and pharmaceutical applications. Their efficient separation from complex aqueous matrices remains a critical challenge in green extraction processes. Ionic liquids (ILs) are recognized as sustainable solvents for liquid–liquid extraction due to their structural versatility and low environmental impact. However, conventional ILs often exhibit suboptimal performance in aqueous two-phase systems (ATPS) for recovering phenolic acids. This study systematically investigated three functionalized imidazolium ILs ([CMmim]BF₄, [CMmim]Cl, [HEmim]Cl) combined with sodium dihydrogen phosphate (NaH₂PO₄) based ATPS to optimize the extraction of phenolic acids (ferulic acid, cinnamic acid, and gallic acid). Through single-factor experiments, the highest efficiencies were achieved under mild conditions (298 K, pH 3.0, phase ratio 9.0): 64.54% for ferulic acid, 72.56% for cinnamic acid, and 80.84% for gallic acid at NaH₂PO₄ concentrations of 0.5 g·mL⁻¹ for FA and CA, 0.45 g·mL⁻¹ for GA, respectively. Thermodynamic analysis revealed enthalpy-driven extraction (ΔH = − 21.62 to − 25.83 kJ·mol⁻¹; ΔS = − 8.00 to − 17.35 J·mol⁻¹·K⁻¹), dominated by hydrogen bonding and van der Waals interactions, as confirmed by UV–vis, FTIR, and ¹H NMR spectroscopy. The functional groups (–COOH, –OH) on ILs were shown to enhance solute–solvent interactions, while NaH₂PO₄ acts as a kosmotropic salt to promote phase separation via the Hofmeister effect. These findings highlighted the potential of functionalized IL-based ATPS for efficient and sustainable extraction of bioactive compounds from aqueous media. They also established a mechanistic framework for designing specific ILs, offering a green alternative to volatile organic solvents in bioactive compound recovery.

In order to explore the effect of caprolactam on the solubility of ammonium sulfate in water, the laser dynamic method was used to measure the solubility of ammonium sulfate in aqueous solutions of caprolactam with different concentrations at temperatures ranging from 293.15 K to 333.15 K. The modified Apelblat equation, λh equation, and Van’t Hoff–Yaws model were employed to correlate the experimental data. It was found that the average relative deviation (ARD) was less than 0.5%, demonstrating a good agreement between the fitted values and the experimental data. Thermodynamic analysis shows that the dissolution of ammonium sulfate in caprolactam aqueous solution is an endothermic process, and the solubility enthalpy of the dissolution estimation system was estimated to be about 2.50 kJ/mol. This study for the first time revealed the inhibitory effect of caprolactam on the solubility of ammonium sulfate, which provided a thermodynamic basis for the crystallization process. In the industrial process, the crystal size and crystallization efficiency of ammonium sulfate can be improved by setting an appropriate caprolactam concentration and crystallization speed.

Based on mother liquor rich in lithium, strontium and bromine obtained from the brine of underground oil–gas field in Qaidam Basin after pre-treatment, the isothermal dissolution equilibrium method was used to study the stable solid–liquid equilibria and phase diagrams of the quinary system LiBr − NaBr − KBr − SrBr₂ − H₂O and its subsystems at 298.15 K. The solubilities of solids in each system were determined, respectively, and the equilibrium solid phases were determined. In order to clearly reflect the regularities and characteristics of phase equilibria of multi-component systems, the corresponding phase diagrams were also plotted and analyzed. The Pitzer model for the quinary system was parameterized by using relevant experimental thermodynamic data. The solubilities of solids in this quinary system and its subsystems were calculated and compared with experimental results. The results not only help to reveal the thermodynamic behavior of relevant bromides in the process of brine concentration, but also provide some theoretical support for the comprehensive utilization of its brine resources.

In this paper, the solubility of 2,4,6-trinitro-3-bromoanisole (TNBA) in methanol, ethanol, n-propanol, n-butanol, dichloroethane, cyclohexane, ethyl acetate, acetonitrile, acetone, benzene, methylbenzene and water over the temperature range of 283.15–323.15 K has been determined for the first time by gravimetric method. In the experimental temperature range, the order of average solubility of TNBA in twelve pure solvents is as follows: acetone (23.1736 × 10^–2) > benzene (16.3735 × 10^–2) > acetonitrile (16.3586 × 10^–2) > ethyl acetate (16.0661 × 10^–2) > methylbenzene (14.4027 × 10^–2) > dichloroethane (11.1222 × 10^–2) > methanol (0.8543 × 10^–2) > ethanol (0.6077 × 10^–2) > n-propanol (0.4664 × 10^–2) > n-butanol (0.4646 × 10^–2) > cyclohexane (0.0693 × 10^–2) > water (0.0186 × 10^–2). The solubility of TNBA in twelve pure solvents was correlated using the modified Apelblat equation, λh equation, van't Hoff model and Jouyban–Acree model, and the predictive accuracy of the four groups of models was evaluated by the R², ARD, and RMSD criteria, and the comparison revealed that Jouyban–Acree model had a better match with the experimental data with the highest accuracy. Additionally, the thermodynamic parameters of TNBA solubility in twelve pure solvents were calculated. The enthalpy of dissolution ((Delta{H}^circ_text{sol})), entropy of dissolution ((Delta{S}^circ_text{sol})), and Gibbs free energy of dissolution ((Delta{G}^circ_text{sol})) at mean temperature in different pure solvents reached 17.14–77.98 kJ·mol⁻¹, − 12.51 to − 78.27 J·mol⁻¹·K⁻¹ and 20.93–101.66 kJ·mol⁻¹, respectively. The results demonstrate that the dissolution behavior of TNBA in the selected solvents is an endothermic and non-spontaneous process.

UV–Vis and FT-IR spectroscopic methods, along with dynamic light scattering (DLS) measurements, were used to investigate the binding of p-nitroaniline (p-NA) in diethyl sulfoxide (DESO) and dimethyl sulfoxide (DMSO)-containing AOT reverse micelles in n-heptane at varying molar ratios of polar solvent to AOT. Both DESO (or DMSO) and DESO (or DMSO) + water mixtures were used as polar solvents. The binding constant (K_b) between p-NA and AOT was calculated for the aforementioned reverse micelles. Variations in the K_b values were interpreted in terms of competitive molecular interactions, taking into account the hydrogen-bond donor ability of p-NA, solvation of counter ion Na⁺ by DESO (or DMSO), the self-associative structure of sulfoxides, and their hydrogen-bonding interactions with water. FT-IR spectra indicate that DMSO or DESO encapsulated within the reverse micelles does not interact with either the C=O or the SO₃⁻ groups of AOT. Notably, significant solvation of the Na⁺ counterion by DMSO results in its displacement from the AOT surface, contributing to an increase in K_b value. DLS measurements confirm that molecular interactions have a significant impact on the size of the reverse micelles.

Deep Eutectic Solvents (DESs) have garnered significant interest due to their diverse applications; however, detailed thermophysical data, especially for density and viscosity, are needed to expand their industrial use. This study developed an Extreme Gradient Boosting (XGBoost) model to predict the density and viscosity of DESs. Experimental measurements were conducted on 494 density data points (308–353 K) and 1600 viscosity data points (293.15–323.15 K) from 40 DESs synthesized by varying the molar ratios of three hydrogen bond acceptors and donors. The dataset was used to train an Extreme Gradient Boosting model (XGBoost) for accurate property prediction. The XGBoost model demonstrated high accuracy, with a mean absolute percentage error (MAPE) of 0.16% for density and 1.5% for viscosity. These results indicate that the model is a reliable tool for predicting key thermophysical properties, facilitating the broader application of DESs in various industries.