Journal of Solution Chemistry最新文献

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.

Solvents play a critical role in separation processes by selectively dissolving or extracting specific components from a mixture, enabling their effective separation. The choice of solvent influences the efficiency, selectivity, and energy consumption of the process, making it a key factor in optimizing separation techniques such as distillation, extraction, and crystallization. The present study highlights a development of several machine learning (ML) models to predict the solubility of a solute in a solvent by using their SMILES as inputs. Molecular descriptors of solutes and solvents are obtained from SMILES of the original dataset. The top 5 descriptors are selected based on Pearson’s coefficient for solutes and solvents and are considered as inputs along with temperature. Different ML models are used for solubility prediction including linear models (linear, lasso, and ridge regression models), tree-based models (decision tree, random forest regressor, gradient boost, xgboost models and AdaBoost models) and other models (support vector regressor, k-nearest neighbor). The random forest model performed well with R² = 0.98, RMSE = 0.0121, and MSE = 0.0001 using training dataset, R² = 0.95, RMSE = 0.0266, and MSE = 0.0007 using testing dataset, and R² = 0.97, RMSE = 0.0161, and MSE = 0.0003 with the overall data. The prediction capability of the model is analyzed with respect to different descriptors and with respect to solutes and solvents, and with respect to temperature dependency. The model selected in the present study can be directly used for solvent design in various separation processes.

The present work presents a critical review on the ionization degree of the micelles (α), analyzing its derivation from electrostatics, as well as the influence of different factors and their interpretation. We have considered the effect of the hydrocarbon chain length, the aggregation number, the polar group’s size and hydrolysis, the counterions´ charge and cases when non-ionic surfactants or alcohol molecules are included into ionic micelles. The appropriate interpretation of α depends not only on the nature of the system studied but also on the methodology employed for its determination. We have concluded that the most appropriate denomination for this property is degree of counterion release.

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This study explores the potential use of sodium bentonite (SB) as a carrier for the broad-spectrum antibiotic levofloxacin (LVO), known for its efficacy against bacterial infections such as those caused by Staphylococcus epidermidis (S. epidermidis). Adsorption experiments were conducted under varying conditions of pH, LVO concentration, temperature, SB dosage, and contact time, with UV spectroscopy employed for quantification. The results demonstrated that LVO adsorption onto SB followed pseudo-second-order kinetics and conformed to the Langmuir isotherm model, suggesting monolayer adsorption. Acidic pH conditions significantly enhanced adsorption efficiency. The SB–LVO composites were extensively characterized using FTIR, SEM, XRD, BET surface area analysis, and TGA, confirming successful drug loading and structural integrity. In vitro release studies under different pH conditions indicated sustained-release behavior, particularly under basic conditions. Antibacterial assays confirmed the efficacy of the SB–LVO composites against S. epidermidis, highlighting their potential as a controlled-release drug delivery system. Given that stomach level acidity significantly reduces LVO release from SB–LVO, strategies to bypass or protect against the gastric environment are warranted. Overall, the findings suggest that SB–LVO composites offer a promising platform for targeted and extended antibiotic delivery, presenting an innovative approach for pharmaceutical formulations in clinical settings.

Hydrazinium cyclo-pentazolate (N₂H₅N₅) is a promising high-energy-density ionic salt characterized by high enthalpy of formation and detonation velocity. To investigate its crystallization thermodynamics, the solubility of N₂H₅N₅ was determined in eleven pure solvents via the static method over the temperature range 278.15–308.15 K. Experimental results demonstrated that the solubility of N₂H₅N₅ is positively correlated with increasing temperature in the selected solvents and the solubility data is well correlated by the modified Apelblat equation, λh equation, Wilson model, and non-random two-liquid (NRTL) model. Furthermore, the mixing thermodynamic properties of N₂H₅N₅ in selected solvents were analyzed by the NRTL model, which indicated that the dissolution process of N₂H₅N₅ in organic solvents is spontaneous by entropy- or enthalpy-driven forces. Solute–solvent interactions were further elucidated through solvation free energy and radial distribution function (RDF) analysis. Crystal morphology predictions for N₂H₅N₅ in vacuum and various solvents revealed that dichloromethane, cyclohexane, and n-hexane solvents have important regulatory effects on the morphology of N₂H₅N₅.

Using a Parr 1455 solution calorimeter, we determined the excess molar enthalpies, (H_{text m}^{text E}) of binary mixtures of ethylene glycol diacetate (EGDA) with propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol, and octan-1-ol at 298.15 K and 81.5 kPa. All mixtures showed positive excess molar enthalpies, suggesting repulsive forces and weaker interactions compared to the pure components. These positive values indicate weaker interactions within the mixtures compared to the pure components. Furthermore, the partial molar enthalpies, (overline{H}_{text m,i}) and the partial molar enthalpies at infinite dilution, (overline{H}_{text m,i}^{infty }) were calculated. The Redlich–Kister polynomial equation was used to correlate the experimental data and Wilson, UNIQUAC, and NRTL models were applied to analyze the excess molar enthalpies.

Excessive water hardness poses significant challenges to both domestic and industrial water usage, often leading to scale formation and reduced efficiency of water systems. In this article, the removal of total hardness using homogeneous Fenton-activated microcrystalline cellulose (MCC-F) extracted from banana pseudo-stem was investigated. To begin with, FTIR, SEM–EDS, XRD, TGA, and pH_pzc of the prepared material were examined to determine its characterization. Next, a preliminary experiment was conducted to assess the adsorption capacity and reduction percentage of target pollutants from a synthetic solution using MCC-F as an adsorbent. Besides, the Freundlich and Dubinin-Radushkovich isotherms demonstrated excellent correlation with the experimental data (R² > 0.99), while the pseudo-second-order kinetic model effectively described the adsorption kinetics. Furthermore, the adsorptive elimination of hardness was found to be an exothermic and spontaneous process, as indicated by thermodynamic studies. This study proposes a straightforward setup that addresses the limitations of conventional methods for removing total hardness.

This study presents the development and performance evaluation of polyethersulfone (PES)-based mixed-matrix membranes (MMMs) integrated with dolomite for enhanced CO₂/N₂ separation. Micronized dolomite was calcined at 800 °C to increase surface area and subsequently modified with stearic acid to improve hydrophobicity. The MMMs were fabricated via phase inversion with varying dolomite loadings (0–0.75 wt.%), including a 0.5 wt.% hydrophobic variant. Comprehensive membrane characterization was performed using FESEM, FTIR, contact angle analysis, and zetasizer. Gas permeation tests revealed that the incorporation of hydrophilic dolomite improved CO₂ permeability up to an optimal 0.5 wt.%, after which agglomeration hindered performance. Notably, the membrane containing 0.5 wt.% chemically modified hydrophobic dolomite (PES-5) exhibited the highest CO₂/N₂ selectivity of 8.62, indicating a 57.3% selectivity improvement over pure PES. These values closely approach Robeson’s upper bound, highlighting the filler’s dual role in enhancing selectivity and mitigating water vapor interference via increased hydrophobicity. The results suggest that dolomite, a naturally abundant and cost-effective mineral, can serve as a functional inorganic filler in MMMs, providing a viable pathway for low-cost, high-efficiency CO₂ capture applications.

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