Journal of Solution Chemistry最新文献

The viscosities of the quinary system NaCl + KCl + CaCl₂ + MgCl₂ + H₂O and its binary subsystems are measured in the temperature range of 288.15 K-308.15 K. The viscosities of binary solutions of MgCl₂, NaCl, and CaCl₂ increase with the increase in concentration. In contrast, for the binary solution of KCl, the viscosity decreases with increasing concentration at low temperature and low concentration. The extended Jones–Dole model that incorporates higher-order term parameters is used to fit the viscosity of binary solutions, with a maximum Average Relative Deviation (ARD) of 1.42%. By comparing the values of the Pearson correlation coefficients, it is found that MgCl₂ has the most significant impact on the viscosity of the quinary system MgCl₂ + KCl + NaCl + CaCl₂ + H₂O, while the impact of KCl is the least. The modified extended Jones–Dole model, with the introduction of parameter G_i, can accurately predict the quinary system, resulting in a maximum AAD value of 0.63%. Moreover, the Hu model is also applied to predict the viscosity of the quinary system, achieving a maximum ARD value being 1.54%. Compared to the Hu model, the modified extended Jones–Dole model performs better. The viscosity calculation models for the quinary system MgCl₂ + KCl + NaCl + CaCl₂ + H₂O in this study contribute key parameters for the design and optimization of the potassium chloride production process.

A polemic is given regarding several of the volumetric properties that Touazi and coworkers reported in their published paper. A critical analysis of the published excess molar volumes for binary decalin + tridecane and decalin + tetradecane mixtures revealed that the values determined at low decalin mole fraction compositions were not consistent with values measured at higher decalin compositions. The analysis further showed that the excess molar volumes for the decalin + tridecane and decalin + tetradecane systems differ significantly from published data reported by independent research groups for binary decalin mixtures containing both smaller (C₅ to C₁₂) and larger (C₁₆) linear alkane molecules.

Calculations of hydration energies are extremely important in physical, chemical, and life sciences, and therefore their values need to be accurately determined if these energies were to be used to derive the proper and correct physico-chemical mechanisms. Here, we prove the existence of absolute correlation between ionization and hydration energies for transition metal cations. The said absolute correlation can be exploited in an unambiguous manner to verify the calculated hydration energies for divalent and trivalent transition metal cations.

The density and viscosity of the pseudo-binary mixtures of eutectic solvent (ES) composed of choline chloride and ethylene glycol ([ChCl/EG]) with dimethylsulfoxide (DMSO) were measured. In order to understand the effect of the mole ratio of ChCl:EG, two ChCl/EG ESs with the mole ratio of 1:3 and 1:4 (abbreviated as [ChCl/EG]_(1:3) and [ChCl/EG]_(1:4) in this work) were prepared. The measurements were carried out by digital vibrating U-tube density meter and Ubbelohde capillary viscometer from 303.15 to 323.15 K at atmospheric pressure (98.5 kPa). The Jouyban–Acree model was applied to correlate the experimental density and viscosity data of DMSO/[ChCl/EG]_(1:3) and DMSO/[ChCl/EG]_(1:4) mixtures. In addition, based on the experimental data, the derived properties of the mixtures, such as excess molar volume and viscosity deviation, were calculated. The comparison and analysis of excess molar volume and viscosity deviation for DMSO/[ChCl/EG]_(1:2) reported in literature and the results obtained in this work were carried out.

The binary system of [Bmim][OAc] (1-butyl-3-methylimidazolium acetate) with NMP (N-methylpyrrolidone) is a potential effective cellulose solvent, and its physicochemical properties and solute–solvent interaction are important to design and understand its application. The physicochemical properties can infer the solute–solvent interaction of a system, especially for an infinite dilution; so, in this work, over the molality range 0.0–2.1 mol·kg⁻¹ and temperature range 288.15–318.15 K, the density and absolute viscosity for the dilute solution of [Bmim][OAc] in NMP were measured and correlated. The apparent molar volume and the relative viscosity were calculated and correlated by Redlich–Rosenfeld–Meyer equation (including parameters (V_{Phi}^0), A_v, B_v) and Jones–Dole equation (including parameters D, F), respectively. Then, the structure behavior of [Bmim][OAc] on solution and the [Bmim][OAc]–NMP interaction were discussed based on the parameters (V_{Phi}^0), A_v, B_v, D, F, and the volume ratio r, limiting apparent molar expansibility (E_{Phi}^0) and the solvation number n_s. The results show that [Bmim][OAc] acts as a structure-maker for the solution, the [Bmim][OAc]–NMP interaction is weaker than the interactions of cation–anion and NMP–NMP, and such effect becomes more and more obvious with increasing temperature. Finally, based on the interactions and the widely accepted solvation hypothesis, the possible better temperature to dissolve cellulose was discussed for the potential cellulose solvent.

The Pitzer–Debye–Hückel equation (PDH) is widely used as the long-range term in electrolyte local composition models to describe the non-ideality of electrolyte solutions in the low concentration range. However, the PDH equation’s derivation typically involves disregarding the third term of the radial distribution function, which leaves uncertainties regarding its impact on asymmetric systems, especially those with high asymmetry. This paper addresses this issue by introducing a trinomial radial distribution function and re-deriving the PDH equation, aiming to evaluate the efficacy of the modified equation in describing various asymmetric electrolyte systems at low concentrations (0–1 mol·kg⁻¹). Initially, the osmotic coefficients of 19 single asymmetric electrolyte systems were fitted using the modified PDH equation (M-PDH). The results demonstrated that the accuracy of the M-PDH equation was significantly higher compared to the original PDH equation, yielding standard deviations (SD) of 0.1812 and 0.4238, respectively. Furthermore, an analysis and recommendation for the distance parameter b were provided. Finally, a comparative analysis was conducted to assess the contributions of the third term of the radial distribution function in contrast to the first two terms to the osmotic coefficients. Overall, this study enhances our understanding of how asymmetry affects the PDH equation in describing the thermodynamic properties of electrolyte systems.

In the production of cyclohexene by benzene hydrogenation, the by-product cyclohexane forms an azeotrope with cyclohexene. For the extraction and distillation of the binary azeotrope (cyclohexene + cyclohexane), the selectivity and relative volatility of 24 different entrainers were compared and the intermolecular interaction forces and interaction energies were analyzed by the DMol3 module of Materials Studio (MS). N, N-dimethylformamide (DMF) was identified as the entrainer, and vapour–liquid equilibrium (VLE) data were measured at atmospheric pressure for the binary system {cyclohexane + cyclohexene} with a temperature range of 354 K to 356 K, the binary system {cyclohexane + DMF} with a temperature range of 354 K to 390 K, and the binary system {cyclohexene + DMF} with a temperature range of 357 K to 421 K. In addition, the thermodynamic consistency of the experimental data was checked using the Wisniak and Van Ness method. The Wilson, NRTL, and UNIQUAC models were used to regress and fit the experimental data to optimize the binary interaction parameters, and the root mean square (RMSD) and average absolute deviation (AAD) values of all models were below 0.01%, indicating that the experimental data provide a basis for the simulation and optimization of the extractive distillation process.

Cloud point (CP) of aqueous solution of metformin hydrochloride (MNH) and triton X-100 (TX-100) was examined in presence of several alcohols (MeOH, EtOH, 1-PrOH, 2-PrOH, and 1-BuOH). The main focal point of this study was to evaluate the cloud development for the combination of TX-100 and MNH, as well as to indicate the mode of how various alcohols influence both the physicochemical parameters and interaction forces of that mixture. The cloud point (CP) measurement technique was chosen because of its broad applicability in both the medical and industrial sectors. As alcohol contents increased, higher CP values of TX-100 and MNH mixture were observed except in aq. 1-BuOH (CP is decreased). In the aqueous alcoholic medium (above 3000 mmol·kg⁻¹), the phase separation of TX-100 (92.7 mmol·kg⁻¹) and MNH (2 mmol·kg⁻¹) mixture showed the subsequent trend: CP (H₂O + 2-PrOH) ˃ CP (H₂O + MeOH) > CP (H₂O + EtOH) ˃ CP (H₂O + 1-PrOH). It was observed that the depth to which alcohol molecules penetrate micelles is influenced by the length of the alcohol chain. Longer hydrophobic alcohol molecules have the ability to impair more ethylene oxide–water (EO-water) interactions by penetrating deeper into the micelle’s palisade layer. As a result, there is more occurrence of dehydration, which promotes the production of micellar particles as well as lowers the cloud point substantially. The calculated ({Delta G}_{c}^{0}) values of the TX-100 + MNH mixture in alcohols media are appeared as positive in every scenario examined, proving that the clouding procedure is not spontaneous. The positive ({Delta G}_{c}^{0}) results might be attributed to the surfactant’s surface layer in forming H-bond via the water molecules. A decrease in the positive ({Delta G}_{c}^{0}) values is evidenced by a rise in alcohol concentrations. Consequently, there is less non-spontaneity at higher alcohol concentrations. The (+{Delta H}_{c}^{0}) (endothermic) and (+{Delta S}_{c}^{0}) magnitudes are detected in aq. MeOH, EtOH, and 2-PrOH solutions. However, ({Delta H}_{c}^{0}) and ({Delta S}_{c}^{0}) magnitudes are found as positive (endothermic) and negative (exothermic) at lower and higher contents of 1-PrOH solution while the opposite trend in the ({Delta H}_{c}^{0}) and ({Delta S}_{c}^{0}) was detected in aq. 1-BuOH solution.

Graphical Abstract

Possible interactions among TX-100 and metformin hydrochloride in aqueous 1-BuOH media

Levulinic acid (LA), a carboxylic acid with a keto-acid structure, has recently been gaining increasing attention as a promising biorefinery platform chemical due to its potential to be feasible and sustainable. This work focuses on using trioctylamine (TOA) to separate LA from an aqueous solution by liquid–liquid extraction. For that, binodal curves and tie lines were determined at T = (293.15, 313.15, and 333.15) K under atmospheric pressure. The slope of the determined tie lines demonstrates that higher extraction efficiencies are possible with higher acid concentrations. Furthermore, infrared spectroscopy (FT-IR) was applied to better understand the behavior of phase diagrams. This study detected the acid-extractant complex formation between (LA) and (TOA). Finally, the experimental data were successfully correlated with the NRTL model at all the measured temperatures. The obtained parameters were applied using a decanter model.