Polymer solubility in mixed solvents

Modeling results indicate that polymer chains in mixtures of a good with a bad solvent exhibit preferential adsorption of the good solvent. That phenomenon is found to be strongly dependent on molecular weight and it increases with a decrease in chain length. These results have important consequences on polymer solubility. Thus, a low molecular weight chain in a solvent mixture behaves as if it were dissolved in the pure good solvent component, whereas the solubility of a longer chain is controlled by the average mixture composition. As a result, quenching a polydisperse system below the cloud point may induce molecular weight segregation between the two phases: the longer chains, which precipitate out first, tend to populate the polymer rich phase whereas the shorter chains, having greater solubility, remain in the solvent phase. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2782–2787, 1999     

Solid solubility in the Bi-Sb-As ternary system

The existence region of the ternary solid solution in the Bi-Sb-As system is studied using DTA, X-ray powder diffraction, and thermodynamic calculations. The alloys of this system have positive nonideality, which is mainly due to the elastic component of the enthalpy of mixing. The nonideality increases as the antimony concentration in the sample decreases, and finally brings about the instability and decay of the solid solution. It is shown experimentally that complete miscibility is observed at high antimony concentrations, when the antimony atom fraction is higher than or equal to 0.75–0.80.     

Structure-composition relationships in ternary solvents containing methylbenzoate

Thermophysical properties of the hexane+1-chlorohexane (or hexanoic acid or diisopropylether)+methylbenzoate ternary systems and their binary constituents are reported at 298.15 K and 0.1 MPa over the whole composition range. The properties and the optimized geometry of the gas-phase components were appraised from the density functional theory. To find out the causal link between the thermophysical measurements and the molecular level features, the derived mixing and excess functions of the ternary systems were looked into according to the scaled particle and Kirkwood-Buff analyses. The hydrogen bonding and dipole interactions along with the geometry effects brought about by the very different size and shape of the components give rise to complex mixed structures. Application of semiempirical models and use of simple cubic equations of state combined with a one-parameter van der Waals mixing rule has led to prediction of the ternary properties with variable degree of precision.     

Extraction of aroma compounds in blackcurrant buds by alternative solvents: Theoretical and experimental solubility study

This study was designed to evaluate the performance of nine alternative solvents (α-pinene, MeTHF, ethyl acetate, methyl acetate, ethyl lactate, butanol, isopropanol, ethanol and CO₂ supercritical fluid) for extracting aromas from blackcurrant buds (Ribes nigrum L) compared to that of n-hexane, commonly used. This study has been performed via experimentation and simulation using Hansen solubility methodology for the comprehension of the dissolving mechanism. Experimentally, the extracts were analysed to compare the solvents performance in terms of aroma compositions. The results indicated that an alternative solvent, i.e. MeTHF, could be the most promising one for n-hexane substitution with good yield and selectivity of aromas.     

Utility of water solubility data for analysis of melting diagrams of anhydrous ternary salt systems

Water solubility data may be used for predicting the relative sizes of salt fields in the melting diagrams of nonreciprocal ternary anhydrous salt systems.     

Prediction of non-isothermal ternary gas-phase breakthrough experiments based on binary data

The results of breakthrough experiments in an adsorption column packed with commercial activated carbon for three binary CO₂/N₂ mixtures as well as for two ternary CO₂/N₂/H₂ mixtures are presented. The experiments were carried out at two different temperatures (25 and 45 °C), four different pressures (1, 5, 10 and 20 bar) and three different flow rates. To analyze the experiments, the breakthrough profiles are simulated using a one-dimensional model consisting of material and energy balances together with the necessary constitutive equations. Transport parameters such as the heat and mass transfer coefficients are fitted to the results from the experiments with the binary mixtures (CO₂/N₂) and then compared to parameters obtained in a previous work (Adsorption 18: 143–161, 2012) for binary CO₂/H₂ mixtures. Furthermore, the parameters obtained for binary mixtures are used to predict the outcome of breakthrough experiments with ternary CO₂/N₂/H₂ mixtures. These simulations are then tested by experiments, showing that their prediction capability is rather satisfactory for a large range of experimental conditions.     

Liquid-liquid equilibria for ternary systems of water-phenol and solvents: data and representation with models

Alvarez Gonzalez, J.R., Macedo, E.A., Soares, M.E. and Medina, A.G., 1986. Liquid-liquid equilibria for ternary systems of water-phenol and solvents: data and representation with models. Fluid Phase Equilibria, 26: 289–302.Liquid-liquid equilibrium data are presented for the systems water-phenol-benzene, water-phenol-ethylbenzene, water-phenol-nonanoic acid, water-phenol-ethyl acetate, water-phenol-isopropyl acetate, water-phenol-n-butyl acetate, water-phenol-isoamyl acetate and water-phenol-cyclohexyl acetate at 25°C and water-phenol-n-hexyl acetate at 25, 35 and 45°C. These systems are of practical interest for solvent extraction studies, as phenol constitutes a valuable raw material in the production of various chemicals and is recoverable from residual waters.The experimental data presented in this paper are correlated in terms of the NRTL and UNIQUAC models and the relevant parameters are presented.     

On the theory of solute solubility in mixed solvents

A series of equations are developed for the study of the effects of cosolvents on the solubility of a solute in mixed solutions where the solute displays a finite solubility. The equations differ depending on the scale used for the solute (and cosolvent) concentrations. The expressions use Kirkwood-Buff integrals to relate the changes in solubility to changes in the local solution composition around the solute and can be applied to study any type of ternary system including electrolyte cosolvents. The expressions provided here differ from previous approaches because of the use of a semi-open ensemble and the extension to finite solute solubilities.     

A flavin analogue with improved solubility in organic solvents

We report the synthesis and initial electrochemical characterization of a benzene-soluble flavin analogue: N(10)-2,2-dibenzylethyl-7,8-dimethylisoalloxazine (DBF, 1). This analogue, which has an unmodified flavin headgroup, is intended for use in the spectroscopic examination of the electronic effects of flavin hydrogen bonding in simple model systems in aprotic, non-hydrogen bonding solvents. With future spectroscopic studies in mind, we have developed a synthetic route, which allows the incorporation of isotopic labels using inexpensive starting materials.     

混配铂(Ⅱ)配合物堆积异构平衡的溶剂效应

在三元混配配合物中配体与配体之间的分子内芳环堆积是配体分子间的一种特殊作用形式 ,并且在溶液中存在着堆积异构平衡。这种由芳环堆积所产生的异构平衡也同样存在于生物体系内 ,并有着重要的生理效应[1 ,2 ] 。因而有关三元混配配合物分子内芳环堆积异构平衡的研究十分活跃[3～ 5] 。本文选定了羧酸系列配体 (ＣＡ)和另一配体 1 ,1 0 邻菲绕啉 (Ｐｈｅｎ)与铂 (Ⅱ)形成的三元混配配合物作为体系 ,系统研究了溶剂极性对三元混配配合物分子内芳环堆积异构平衡的影响。1　实验部分1 1　试剂和溶液标定氯铂酸钾 [Ｋ2 (ＰｔＣｌ4) ]、硝酸 (…