Screening Metal–Organic Frameworks for Separation of Binary Solvent Mixtures by Compact NMR Relaxometry

Metal–organic frameworks (MOFs) have great potential as an efficient alternative to current separation and purification procedures of a large variety of solvent mixtures—a critical process in many applications. Due to the huge number of existing MOFs, it is of key importance to identify high-throughput analytical tools, which can be used for their screening and performance ranking. In this context, the present work introduces a simple, fast, and inexpensive approach by compact low-field proton nuclear magnetic resonance (NMR) relaxometry to investigate the efficiency of MOF materials for the separation of a binary solvent mixture. The mass proportions of two solvents within a particular solvent mixture can be quantified before and after separation with the help of a priori established correlation curves relating the effective transverse relaxation times T_2eff and the mass proportions of the two solvents. The new method is applied to test the separation efficiency of powdered UiO-66(Zr) for various solvent mixtures, including linear and cyclic alkanes and benzene derivate, under static conditions at room temperature. Its reliability is demonstrated by comparison with results from ¹H liquid-state NMR spectroscopy.     

Bulk and Interfacial Properties for CO2-SO2 Binary Mixtures

The perturbed‐chain statistical associating fluid theory (PC‐SAFT) and density‐gradient theory (DGT) were used to construct an equation of state (EOS) for the phase behaviors of carbon dioxide (CO₂)‐sulfur dioxide (SO₂) binary mixtures. The p‐x diagrams at 263 and 333 K, and the p‐T diagrams corresponding to x=0.8871 and 0.6213 were satisfactorily calculated as compared to the experimental data. With the influence parameters of pure components and the equilibrium bulk properties of mixtures as input, the interfacial properties of CO₂‐SO₂ binary mixtures in a wide temperature range were predicted, and the influences of temperature, pressure and bulk properties on the surface tension were discussed.     

Determination of the Concentrations of Binary Mixtures of Glycerine and Water by a Transient Method

The conductivities of binary mixtures of glycerine and water were measured at 20°C by means of a transient method. The equation describing the correlation between concentration and thermal conductivity was determined. The equation can be used for determining concentrations in mixtures. The results show that (1) the error in the determination of the molar concentration of water in mixtures is less than 1%, (2) the time of measurement is 1 s, (3) this method can be used for on-line analysis in production control. This revised version was published online in July 2006 with corrections to the Cover Date.     

An Equation for the Correlation of Viscosities of Binary Mixtures

Knowledge of the viscosity of binary mixtures is of great importance in many industrial processes. Rarely can the viscosity of mixtures be obtained from the sum of the viscosities of the pure components. The theoretical study of the viscosity of mixtures is generally complicated. Numerous empirical correlation models have been proposed. The present study proposes a new empirical correlation equation, based on lineal behavior. The equation can easily be used with one, two or three parameters, and in many cases it improves upon the models that are commonly used. Likewise, the excess viscosity calculated with the proposed equation generally yield more satisfactory results than those obtained with the polynomial equation of Redlich-Kister.     

Excess Molar Polarization in Binary Mixtures of Polar Liquids

Abstract

Excess Molar Polarizations (ΔP _W.Q., ΔP _D.D.) have been evaluated in the binary mixture of associated + associated and associated + nonassociated polar liquids using Winkelmann-Quitzsch and Davis-Douheret equations. It is observed that Winkelmann-Quitzsch equation ΔP _W.Q. is the more appropriate one for interpretation of dynamic characteristics of the molecular association in a liquid mixture.     

Excess Enthalpies of Binary Mixtures of Formamide with Secondary Amides

The excess molar enthalpies H^E of binary mixtures of formamide with N-methylformamide, N-ethylformamide, N-methylacetamide, N-ethylacetamide and N-methylpropion-amide have been measured as functions of the mole fraction at 308.15 K, using an isoperibol rotating calorimeter. The experimental values of H^E are negative for all mixtures over the whole composition range. Intermolecular interactions in these mixtures are discussed through comparison of the results with those for corresponding binary mixtures of water. This revised version was published online in August 2006 with corrections to the Cover Date.     

Physicochemical Methods Used to Study Internal Structures of Liquid Binary Mixtures

Abstract

Different methods, based on application of studies of intensive physicochemical properties of liquid binary mixtures and ¹H-NMR spectral measurements, used in the analysis of intermolecular interactions and estimation of the internal structure of these mixtures and here reviewed.     

Binary Adsorption of Phenol and m-Cresol Mixtures onto a Polymeric Adsorbent

Adsorption processes are gaining interest as methods of purifying industrial effluents. Most industries discharge effluents containing several components. The adsorption of phenol and m-cresol mixtures from aqueous solutions onto a macroporous polymeric adsorbent, Duolite ES-861, was investigated experimentally in a fixed-bed adsorber for different flowrates, feed concentrations and bed initial conditions (clean or pre-saturated).The experimental results are presented in this work, where the major objective is placed on the modelling of these fixed bed adsorption experiments using an extended Langmuir isotherm equation for two components, based on single component equilibrium data obtained for phenol and m-cresol.The model presented in this paper takes into account axial dispersion of the liquid phase, film diffusion and intraparticle mass transfer and successfully simulates the adsorption behaviour of the phenol and m-cresol mixtures.     

The Binary Mixtures of Lambda-Cyhalothrin,Chlorfenapyr, and Abamectin,against the House Fly Larvae,Musca domestica L.

The house fly Musca domestica L. is one of the medical and veterinary pests that can develop resistance to different insecticides. Mixing insecticides is a new strategy for accelerating pest control; furthermore, it can overcome insect resistance to insecticides. This study aims to evaluate three insecticides, chlorfenapyr, abamectin, and lambda-cyhalothrin, individually and their binary mixtures against 2nd instar larvae of M. domestica laboratory strain. Chlorfenapyr exhibited the most toxic effect on larvae, followed by abamectin then the lambda-cyhalothrin. The half-lethal concentrations (LC₅₀) values were 3.65, 30.6, and 94.89 ppm, respectively. These results revealed that the high potentiation effect was the mixture of abamectin/chlorfenapyr in all the mixing ratios. In contrast, the tested combination of lambda-cyhalothrin/abamectin showed an antagonism effect at all mixing ratios against house fly larvae. The total protein, esterases, glutathione-S-transferase (GST), and cytochrome P-450 activity were also measured in the current investigation in the larvae treated with chlorfenapyr. Our results indicate that GST may play a role in detoxifying chlorfenapyr in M. domestica larvae. The highest activity of glutathione-S-transferase was achieved in treated larvae with chlorfenapyr, and an increase in cytochrome P-450 activity in the larvae was observed post-treatment with Abamectin/chlorfenapyr.     

Solubility of Anthracene in Binary Carbon Tetrachloride + Alkane Solvent Mixtures

Abstract

Experimental solubilities are reported for anthracene in binary solvent mixtures containing carbon tetrachloride with n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane and isooctane at 25°C. Results of these measurements, combined with the excess Gibbs free energies of the binary solvents, are used to test predictive expressions derived from the nearly ideal binary solvent (NIBS) model. Expressions based on a volume fraction average of solute properties in the two pure solvents predict anthracene solubilities to within a maximum deviation of 4.5% and an overall average deviation of 1.8%.     

Compatibility and Stability Studies of Propranolol Hydrochloride Binary Mixtures and Tablets for TG and DSC-photovisual

This study demonstrates the thermalanalysis applications in compatibility and stability studies of the propranolol binary mixture sand tablets A and B. The propranolol binary mixtures were prepared in the laboratory and compared to the fully formulated tablets using the thermogravimetric (TG) and calorimetric(DSC) methods. DSC of binary mixtures showed similar phase transition to propranolol drug. The tablets phase transition decreased and there was no detectable significant interaction in propranolol–lactose mixture and tablets. The DSC-photovisual test revealed an interaction similar to the Maillard reaction. The TG isothermal study showed a difference in the profile between the drug and tablets due excipients quality and problems in manufacture process. The kinetic parameters indicated a lower stability for the tablets than propranolol drug. The thermal techniques thermally differentiated the propranolol preparations demonstrating the importance in the design development of pharmaceuticals solid-dosage form. This revised version was published online in July 2006 with corrections to the Cover Date.     

First Binary Mixture Ionic Liquids Containing EMIMBr and IM

A new series of binary mixture ionic liquids comprising 1-ethyl-3-methylimidozalium bromide(EMIMBr) and imidazole(IM) have been synthesized.The melting prints of the ionic liquids vary with te different content of IM while they still keey satisfactory conductivity and viscosity.According to the analysis of its phase diagram,the cutectic point is about 16.5℃ with the mass percentage of IM 29%.     

Excess Molar Volume and Viscosity of Isobutyric Acid + Water Binary Mixtures Near and Far Away from the Critical Temperature

The excess molar volume V^E, shear viscosity deviation Δη and excess Gibbs energy of activation ΔG^∗E of viscous flow have been investigated by using density (ρ) and shear viscosity (η) measurements for isobutyric acid + water (IBA+W) mixtures over the entire range of mole fractions at five different temperatures, both near and close to the critical temperature (2.055K ≤ (T−T_c)≤ 13.055K). The results were also fitted with the Redlich–Kister equation. This system exhibited very large negative values of V^E and very large positive values of Δη due to increased hydrogen bonding interactions and correlation length between unlike molecules in the critical region and to very large differences between the molar volumes of the pure components at low temperatures. The activation parameters ΔH^∗ and ΔS^∗ have been also calculated and show that the critical region has an important effect on the volumetric properties.     

Thermal Analysis of Solid-Solid Interactions in Binary Mixtures of Alkylcyclohexanes Using DSC

Differential scanning calorimetry (DSC) was used to construct phase diagrams of binary mixtures of alkylcyclohexanes and to characterize metastable phases formed in the binary mixtures. The experimentally measured liquidus curves were compared to the liquidus curves calculated using ideal solution theory. The measured phase diagrams of pentadecylcyclohexane/nonadecylcyclohexane and octadecylcyclohexane/nonadecylcyclohexane binary mixtures are consistent with theoretical phase diagrams constructed based on the assumption that these mixtures form eutectic systems. It was also observed that a metastable phase formed in some binary mixtures of pentadecylcyclohexane/nonadecylcyclohexane under fast cooling conditions. It is hypothesized that this metastable phase recrystallizes into the eutectic phase upon heating. This revised version was published online in July 2006 with corrections to the Cover Date.     

Ultrasonic Studies of Binary Mixtures of p-Chlorotoluene with l-Alcohols at 303.15 K

Abstract

Ultrasonic sound velocities and densities were measured for the binary mixtures of p-chlorotoluene with l-alcohols. The alcohols included: l-propanol, l-butanol, l-pentanol, l-hexanol and l-heptanol. Isentropic compressibilities, k_s and deviation in isentropic compressibility, K_s from ideal behaviour have been calculated from the results. The deviation in isentropic compressibility has been ascribed to competition between structure-breaking and structural effects to different extents.     

Temperature Dependence of Kerr Coefficient of Binary Liquid Mixtures of Aprotic-Aprotic Molecules

Abstract

The electro optical Kerr coefficients of binary liquid mixtures, comprising of aprotic-aprotic molecules only, are measured over the temperature range of 286 K to 315 K. To with in experimental errors, the logarithm of Kerr coefficient can be expressed as Van't Hoff type expression to the reciprocal of temperature. Information on the interaction energy between the constituents of the binary mixtures is thereby obtained. It is found that the interaction energy in aromatic ketone-aliphatic nitrile binary mixtures is comparatively higher than in the binary mixtures with aliphatic ketone-aliphatic nitriles, aromatic ketone-aromatic nitrile and aromatic ketone-aliphatic ketones components. This is attributed to the dipole-dipole interaction existing between the components of the binary mixtures.     

Densities,Ultrasonic Speeds,Viscosities and Refractive Indices of Binary Mixtures of Benzene with Benzyl Alcohol,Benzonitrile, Benzoyl Chloride and Chlorobenzene at 303.15 K

Densities,ρ, ultrasonic speeds, u, viscosities,η, and refractive indices, n, of pure benzene, benzyl alcohol (BA), benzonitrile (BN), benzoyl chloride (BC), chlorobenzene (CB) and their thirty six binary mixtures, with benzene as common component, were measured at 303.15 K over the entire mole fraction range. From these experimental data the values of deviations in ultrasonic speed, △u, isentropic compressibility, △k_s,excess acoustic impedance, Z^E, deviation in viscosity, Dh, and excess Gibbs free energy of activation of viscous flow, G^*E, and partial molar isentropic compressibility, Kφ,2⁰ of BA, BN, BC and CB in benzene were computed. The variation of these derived functions with composition of the mixtures suggested the increased cohesion (molecular order) in the solution and that interaction (A-B)＞(A-A) or (B-B).Moreover, theoretical prediction of ultrasonic speed, viscosity and refractive index of all the four binary mixtures was made on the basis of empirical and semi-empirical relations by using the experimental values of the pure components. Comparison of theoretical results with the experimental values was made in order to assess the suitability of these relations in reproducing the experimental values of u, η and n. Also, molecular radii of pure liquids and the average molecular radii of binary mixtures were evaluated using the corresponding refractive indices of pure liquids and binary mixtures. The average molecular radii of binary mixtures were found to be additive with respect to mole fraction of the pure component.     

Solubility of Trans-Stilbene in Binary Alkane + 1-Propanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 1-propanol solvent mixtures at 25°C. the alkane cosolvents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. for the six system studied, the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation provided the better mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being approximately 0.4%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Solubility of Trans-Stilbene in Binary Alkane + 1-Butanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 1-butanol solvent mixtures at 25°C. The alkane cosoivents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. For the six systems studied, the Combined NIBS/Redlich-Kister equation was found to provide the better mathematical representation of the experimental data, with overall average absolute deviations between measured and calculated values being approximately ±0.6%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Calculation of Viscosity and Diffusion Coefficients for Two Binary Gaseous Mixtures Using the Semi-empirical Inversion Method

The accurate reduced potential energies for two binary gas mixtures including benzene-methanol and methane-tetrafluoromethane at low density have been obtained by direct inversion of the viscosity collision integral equations. The kinetic theory along with the extended principle of corresponding-states has been used to calculate the viscosity and dif-fusion coefficients over a wide range of temperature and composition. Good agreements between calculated and experimental data are obtained.