Binary Mixture System Research Articles

Solid-liquid phase equilibrium of clozapine in aqueous binary solvent mixtures

The solid-liquid phase equilibrium solubility of clozapine in six of aqueous binary solvent mixtures (i.e., water + methanol, water + ethanol, water + n-propanol, water + acetone, water + N, N-dimethylformamide, and water + tetrahydrofuran) was determined from 278.15 K to 323.15 K at approximately 101.3 kPa with a gravimetric method. The solubility increases with the increase of temperature and the composition of good-solvent in all the selected binary solvent mixture systems. Polarity is an essential factor affecting the solubility of clozapine in mixed solvents. Hansen solubility parameters were used to analyse the solubility behaviour. Four thermodynamic models, including the CNIBS/R-K model, the modified Jouyban-Acree model, the NRTL model, and the Wilson model were chosen to fit the experimental solubility data. Relative average deviation, and root mean square deviation were employed to evaluate the fitting degree of each thermodynamic model. NRTL model fits best with the maximum RAD and RMSD value of 0.0177 (water + methanol) and 0.000847 (water + THF), respectively. Solubility data are the basis for calculation of supersolubility and induction time of the crystallization process. The basic solubility data play an important role in the process optimization of clozapine crystallization.

Molecular Dynamics Simulation of Evaporation Coefficient of Vapor Molecules During Steady Net Evaporation in Binary Mixture System

Molecular Dynamics Simulation of Evaporation Coefficient of Vapor Molecules During Steady Net Evaporation in Binary Mixture System

Computer simulations for the adsorption and separation of CH4/H2/CO2/N2 gases by hybrid ultramicroporous materials

The adsorption isotherms of two types of hybrid ultra-microporous materials SIFSIX-3-M (M = Fe, Cu, Zn) and M′FSIX-2-Cu-i (M′ = Si, Ti, Ge) for H2, CH4, CO2 and N2 are comparatively studied by grand canonical Monte Carlo simulation (GCMC), and their differences are explained from pore structure and isosteric heat of adsorption. Natural gas and biogas upgrading (CO2/CH4), synthesis gas separation (CO2/H2), flue gas separation (CO2/N2), and steam methane reforming hydrogen production (CH4/H2) are simulated equimolar binary mixture system. The related separation factors are elucidated from the adsorption selectivity and the difference of isosteric heat of adsorption. The microscopic adsorption mechanism of the material is further analyzed by the preferential adsorption sites of the gas on the framework. Our works provide new insights into the adsorption and separation mechanism of HUMs for the energy-related gas, as well as in industrial application.

Quantitative characterization of toxicity interaction within antibiotic-heavy metal mixtures on Chlorella pyrenoidosa by a novel area-concentration ratio method

Toxicity interaction, synergism and antagonism, may occur when multiple pollutants are exposed to the environment simultaneously, which limits the utility of some standard models to assess toxicity hazards and risks. The development and application of models which can provide an insight into the combined toxicity of pollutants becomes necessary. Therefore, a novel model, area-concentration ratio (ACR) method, was developed to characterize the toxicity interaction within mixtures of three aminoglycoside antibiotics (AGs), kanamycin sulfate (KAN), paromomycin sulfate (PAR), tobramycin (TOB) and one heavy metal copper (Cu) in this study. The inhibition toxicity of single contaminants and mixtures designed by direct equilibration ray method and uniform design ray method to Chlorella pyrenoidosa (C. pyrenoidosa) was determined by the microplate toxicity analysis (MTA). The results showed that the novel method ACR could be used for quantitative characterization of combined toxicity. According to the ACR, all the binary AG antibiotic mixture systems display obvious synergism and weak antagonism. The addition of the heavy metal Cu into binary AG antibiotic mixtures can obviously change toxicity interaction, but toxicity interaction changing trend varies greatly in different ternary mixture systems. Toxicity interaction in the six mixture systems has component concentration-ratio dependence. ACR can be suggested as an effective novel method to quantitatively characterize toxicity interaction when assessing the hazards and risks of the combined pollution.

Molecular insight of flow property for gas-water mixture (CO2/CH4-H2O) in shale organic matrix

Gas-water two-phase flow mechanism of CO2/CH4 in moist nanoporous media is significant in carbon capture and storage (CCS) and enhanced oil and gas recovery (EOR) technology. However, in untraditional oil and gas exploitation, the flow property of CO2/CH4-H2O mixtures are neglected in shale organic nanopores under reservoir conditions. In this work, molecular dynamic simulation combined with a theoretical model is performed to investigate two-phase flow characteristics of CH4/CO2-H2O mixtures in shale organic nano-slits. From the density profile of gas-water mixtures in shale organic nano-slits, we find that water molecules prefer to form water clusters at the surface and center region to replace CH4 molecules of the adsorption layer (AL) and CO2 molecules of the bulk-free layer (BL), respectively. Based on the results of MD simulations, an analytical theoretical slip model is established to quantitatively characterize the effective viscosity and slip length of CH4/CO2-H2O binary mixtures systems, which can be integrated into the macro framework to mimic the flow property of gas-water two-phase in shale and predict the apparent gas permeability in moist shale. Particularly, although the viscous flux of CO2 decreased with the increase of gas water mole percent (GWP) values and the slippage flux appears largely unaffected, the variation of total flux for CO2 has been small. Taking into account the influence mechanisms of H2O molecule among the gas-water (CH4/CO2-H2O) two-phase mixtures in shale organic nano-slits, CO2 displacement and fracturing technology may provide a productivity improvement avenue for shale gas.

Ferroelectric Liquid-Crystalline Binary Mixtures Based on Achiral and Chiral Trifluoromethylphenylterthiophenes

This paper presents a new family of ferroelectric smectic liquid-crystalline binary mixtures composed of achiral and chiral trifluoromethylphenylterthiophenes. The chiral symmetry breaking of the ferroelectric smectic phases can lead to chiral photovoltaic (CPV) effects, as a type of ferroelectric photovoltaic (FePV) effect, which is caused by the internal electric field originating from the spontaneous polarization. These ferroelectric properties were examined using the Sawyer-Tower method, and the CPV effect was confirmed by measuring the steady-state photocurrent response under zero bias. We found that the remnant polarization and photocurrent density in the polarized ferroelectric phases increased nonlinearly with the increase in the content of the chiral component in the mixture. Moreover, the hole mobility evaluated by time-of-flight measurements was kept constant by varying the composition. More than 40 mol % of the chiral component was required to form the polar structure, inducing the CPV effect. Binary mixture systems are advantageous for not only optimizing liquid crystal structures and temperature ranges but also facilitating the design of materials exhibiting CPV effects.

Temperature relaxation in binary hard-sphere mixture system: Molecular dynamics and kinetic theory study.

Computational schemes to describe the temperature relaxation in the binary hard-sphere mixture system are given on the basis of molecular dynamics (MD) simulation and renormalized kinetic theory. Event-driven MD simulations are carried out for three model systems in which the initial temperatures and the ratios of diameter and mass of two components are different to study the temporal evolution of each component temperature in nanoscale molecular conditions mimicking those in living cells. On the other hand, the temperature changes of the two components are also described in terms of a mean-field kinetic theory with the correlation functions calculated in the Percus-Yevick approximation. The calculated results by both the computational approaches have shown fair agreement with each other, whereas slight deviations have been found in the temporal range of femto- to picoseconds when the initial temperatures of the two components are significantly different, such as 300 K vs 1000 K. This discrepancy can be ascribed to the fast intra-component temperature relaxation assumed in the kinetic theory, and its violation in the MD simulations can be evaluated in terms of the Kullback-Leibler divergence between the equilibrated Maxwell-Boltzmann distribution at each temperature and the actual non-equilibrium velocity distribution realized in the MD. Thus, the present analysis provides a quantitative basis for addressing the temperature inhomogeneities experimentally observed in nanoscale crowding conditions.

Packing potential index for binary mixtures of granular soil

Packing procedure is the mechanical process of forming a packing of soil particles, such as funnel pouring, tamping, rodding, pluviation, compaction, vibration, compression, etc. For a sand-silt mixture, packing procedure and particle shape have significant effects on the density of the binary mixture. However, these two factors have not been considered in most of the existing particle packing density models. Thus, the existing particle packing density models are not applicable to sand-silt mixtures. In this paper, we aim to study the packing procedure and particle shape effects on density of binary mixtures. We firstly define a packing potential index, which is a measure of volume reduction potential due to mixing of two components of a binary mixture system under a packing procedure. To understand the nature of packing potential index, we compare the packing potential indices of 24 different types of mixtures collected from the literature; the 24 types of mixtures were formed by two different types of packing procedure (i.e., for achieving minimum and maximum void ratios). It is found that the packing potential index is nearly independent of packing procedure but significantly dependent on the compound particle shapes of a mixture. Then, we mathematically link the packing potential index to the particle interaction parameters used in the particle packing density models. And we analyze the data to discuss the effect of packing procedure on the void ratios of sand-silt mixtures. We then propose an approach within the framework of particle packing density model to predict the void ratios of sand-silt mixtures under different packing procedures with the consideration of particle shape effect.

Modulating the crystallization of phytosterols with monoglycerides in the binary mixture systems: mixing behavior and eutectic formation

Phytosterols (PSs) are insoluble in water and poorly soluble in oil, which hampers their potential as cholesterol level regulator in human. To mitigate this problem, monoglycerides (MGs) were used to modulates the crystallization behavior of PSs. Therefore, the understanding on mixing behavior provides the insight into different aspects of crystallization and the resultant effects. The effects on thermal, morphology, diffraction, and spectroscopy behavior were investigated for binary mixtures of 11 different ratios (100:0 to 0:100 MGs:PSs). The phase behavior of binary mixtures of commercial MGs and PSs exhibited complexity with the formation of eutectic mixtures at 90:10 and 80:20 (MGs:PSs) combinations. These combinations revealed a single melting profile and reduced melting enthalpy, though after a month of storage at 5 °C. Conversely, two separate melting regions were observed in others. Furthermore, powder X-ray diffraction (PXRD) analysis of selected combinations revealed a change in crystalline forms with changes in the peaks located between 18-19° (2θ) and 25-26° (2θ). Accordingly, Raman spectroscopy results revealed changes in intensities and peak shape. Therefore, the change in crystalline forms or behavior correlated well to the change in thermal properties. Overall, the characterizations revealed the formation of eutectic mixtures between MGs and PSs at 90:10 and 80:20 (MGs:PSs) in which MGs modified the crystallization of PSs and changed the crystal forms thus, thermal behaviors. This study provides new insight into the mixing behavior of MGs and PSs which supports other research. Therefore, the results of this study are beneficial for the improvement of formulation of phytosterols in food and pharmaceutical products. Nonetheless, this study reveals a simple technique to alter crystal forms of phytosterols through simple complexation with monoglycerides.

Stability of non-classical thermoelasticity mixture problems

We discuss the stability problem for binary mixtures systems coupled with heat equations. The present manuscript covers the non-classical thermoelastic theories of Coleman-Gurtin and Gurtin-Pipkin - both theories overcome the property of infinite propagation speed (Fourier's law property). We first state the well-posedness and our main result is related to long-time behavior. More precisely, we show, under suitable hypotheses on the physical parameters, that the corresponding solution is stabilized to zero with exponential or rational rates.

Study on Test and Ratio Optimization of Waste Rock-Fly Ash Aggregate Filling Slurry

To obtain the optimum proportion of fly ash alternative for preparing filling slurry instead of waste rock, the effect of fly ash dosage on the filling body strength is predicted by utilizing BP neural network model on the basis of experimenting the particle size distribution, filling body strength and slurry working characteristics of waste rock-fly ash binary aggregate system under various fly ash dosages. As the results revealed, the waste rock-fly ash binary mixture system attains the densest accumulation when the fly ash dosage is 30%. At this point, the compressive strengths at all ages reach the maximum, according to the BP neural network model predictions. The minimum cost for preparing filling slurry is obtained to be 121 yuan/m3 based on the cost optimization model. At this time, the fly ash dosage is 26%, the cementitious material consumption is 286 kg/m3, the slurry concentration is 81%, the 3d strength is 1.26 MPa, the 7d strength is 1.52 MPa, the 28d strength is 5 MPa, the expansion degree is 51.4 cm, and the bleeding rate 5.7%. Both the filling body strength and slurry fluidity conform to the requirements, while the fly ash dosage is almost identical to that obtained from the particle size distribution and filling body strength tests.

Measurement of the Solubility of Diclazuril and Discussion of the Effect of the Cosolvent

In this research, the solid–liquid equilibrium solubility of diclazuril was measured by the isothermal saturation method, and the influence of the solvent effect on solubility was discussed. In monosolvents, at the determined temperature, the solubility values of diclazuril decrease according to the order: dimethylformamide (DMF) > acetone > acetonitrile > ethyl acetate > methanol > ethanol > 1-propanol > 2-propanol > 1-butanol > toluene. Besides, in two binary solvent mixtures, the solubility increases with the increasing ratio of DMF/acetone and decreases with the increase of ethanol. What is more, five models including modified Apelblat equation, λh equation, Jouyban–Acree model, van’t Hoff–Jouyban–Acree model, and Apelblat–Jouyban–Acree model were used to correlate the diclazuril solubility in monosolvents and binary solvent mixture systems. The relative average deviation and root-mean-square deviation values were no more than 0.97% and 6.95 × 10–4, respectively. All these five models can correlate th...

Prediction of thermal conductivity of liquid and vapor refrigerants for pure and their binary, ternary mixtures using artificial neural network

The determination of thermophysical properties of hydrofluorocarbons (HFCS) is very important, especially the thermal conductivity. The present work investigated the potential of an artificial neural network (ANN) model to correlate the thermal conductivity of (HFCS) at (169.87-533.02) K, (0.047-68.201) MPa, and (0.0089-0.1984) W/(m·K) temperature, pressure, and thermal conductivity ranges, respectively, of 11 systems from 3 different categories including five pure systems (R32, R125, R134a, R152a, R143a), four binary mixtures systems (R32 + R125, R32 + R134a, R125 + R134a, R125 + R143a), and two ternary mixtures systems (R32 + R125 + R134a, R125 + R134a + R143a). Each one received 1817, 794 and 616 data points, respectively. The application of this model for these 3227 data points of liquid and vapor at several temperatures and pressures allowed to train, validate and test the model. This study showed that ANN models represent a good alternative to estimate the thermal conductivity of different refrigerant systems with a good accuracy. The squared correlation coefficients of thermal conductivity predicted by ANN were R2 = 0.998 with an acceptable level of accuracy of RMSE = 0.0035 and AAD = 0.002 %. The results of applying the trained neural network model to the test data indicate that the method has a highly significant prediction capability.

Predicting the hormesis and toxicological interaction of mixtures by an improved inverse distance weighted interpolation

The prediction of toxicological interactions and hormesis of chemical mixtures is important because organisms are mostly exposed to numerous contaminants and typically to low dose of these mixtures, and it is still a challenge. Although many models have been developed to predict the mixture toxicities such as concentration addition (CA) and independent action (IA), they cannot solve these challenges perfectly. This study has developed an improved inverse distance weighted (IDW) interpolation for prediction of the mixture toxicities. IDW uses the mixture and the single compound as scatter points in space, and the space can be constructed by the concentration axes of various components in the mixture system. Some known mixtures (or the single compound) closest to the unknown mixture are selected as interpolation nodes. To be more accurate in calculation, a new normalization method for concentration has been proposed through dividing the concentration of the mixture and the single compound by the respective EC50 values. Sixteen binary mixture systems are selected for leave-one-out cross-validation and three binary mixture systems are selected for external validation. The results show that the accuracy of IDW is ≥95% for three types of mixtures including no hormetic component, one hormetic component (show no toxicological interaction), and two hormetic components. The IDW also show higher prediction accuracy than that of CA and IA. The IDW developed in this study can be used to predict the toxicity of various mixture systems, thus providing predictive information for chemical mixtures risk assessment.

The Volumetric and Transport Properties of 1-Ethyl-3-Methylimidazolium Trifluoromethanesulfonate Ionic Liquid and Propylene Carbonate Binary System

In the present work, a new binary mixture system composed of the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([Emim][CF3SO3]) and propylene carbonate (PC) was prepared. The densities, dynamic viscosities, and electrical conductivities of ([Emim][CF3SO3] + PC) were measured over the whole concentration range (mole fractions of IL from 0 to 1) for temperatures from 288.15 to 353.15 K. The excess molar volumes (VE) and viscosity deviations (Δη) of the binary systems were calculated to characterize the volume contraction and intermolecular interactions in the mixture system, and both were correlated with the Redlich–Kister polynomial equation. The Vogel–Fulcher–Tamman equation was used to describe the temperature dependences of the dynamic viscosities and the electrical conductivities of the binary system. Further, density functional theory calculations were employed to obtain the structure, energy, and COSMO charge distributions of the cation and anion of the IL and the PC molecule, and the intermolecular interactions in the binary mixture system were evaluated.

Phase equilibria for binary mixtures of hexane with orthoxylene, metaxylene, and nonane with hexane at 101.3 kPa

Experimental measurements of isobaric vapour, liquid equilibrium boiling point temperature were determined at 101.3 kPa as function of concentration for the two mixtures of hexane with orthoxylene, metaxylene and nonane with hexane by using a continuous recirculation type apparatus. The measured temperature, vapour and liquid concentration (T-x-y) results were correlated with the NRTL and the UNIQUAC models. Each binary mixture system has passed the thermodynamic consistency test of Herington. The activity coefficient values (ᵧ) are greater than unity in three systems for all measurements. The systems studied in the present investigation are hexane with orthoxylene, metaxylene and nonane with hexane show relatively larger deviations from Results' law. All the systems studied here behave like non-ideal solutions. All binary systems investigated were found to be nonazeotropic in nature.

Toxicological Interactions of Organophosphorus Pesticides Mixtures to Chlorella pyrenoidosa

The toxicity effects of combined pesticides pollution have potential risks to aquatic environment. To investigate the combined toxicity effects of organophosphorus pesticides (OPs) mixtures on green algae in freshwater ecosystems, five OPs, i.e. malathion (MIT), dichlorvos (DDVP), trichlorfon (TRC), dimethoate (DIT) and omethoate (OMT), were selected as the mixture components. Nine OPs binary mixture systems contained 45 mixture rays were designed by a direct equipartition ray design (EquRay) method. The growth inhibition toxicities of the five single OPs and 45 binary mixture rays to Chlorella pyrenoidosa (C. pyrenoidosa) were determined using the 96-well microplate. Combination index based on the confidence intervals method was applied to analyze the toxicological interactions in OPs binary mixtures. Taking the negative logarithm of median effective concentration (pEC50) as toxicity index, the toxicity order of five OPs was as follows: TRC > MIT > DDVP > OMT > DIT. The toxicity of single OPs to C. pyrenoidosa was affected by the electropositivity of its phosphorus. The combined toxicity of some OPs mixtures depended on component concentrations. The toxicological interactions of OPs mixtures on C. pyrenoidosa were dominated by additive action, and some mixtures presented antagonism behavior. In addition, the mixture systems with antagonism displayed additive effects at low-effect regions and showed antagonistic effects at high-effect regions. The antagonism of the mixture systems containing MIT were strengthened with the increasing of MIT concentration ratio. It was worth noting that the toxicological interactions of OPs mixtures were related to component concentration ratio. Meanwhile, the concentration-ratio-dependent interactions of OPs mixtures were not associated with their concentration-ratio-dependent toxicity.

Volumetric and Optical Properties of Dimethylvinylethoxysilane with n-Alkanes (C7 to C10) at Temperatures in the Range (298.15 to 318.15) K

Densities and refractive indices are investigated for four binary mixture systems of dimethylvinylethoxysilane with n-heptane, n-octane, n-nonane and n-decane at different temperatures (298.15, 303.15, 308.15, 313.15 and 318.15 K) and atmospheric pressure. From these experimental data, the excess molar volume, isobaric coefficient of thermal expansion, deviation in refractive index, molar refraction, and deviation in the molar refraction have been calculated. The computed quantities have been fitted with the Redlich–Kister equation to derive the coefficients and estimate the standard deviations. The values of the partial excess volume at infinite dilution were calculated using the coefficients of the Redlich–Kister smoothing equation. The effects of composition and temperature on these properties are discussed.

Flash points measurements and prediction of biofuels and biofuel blends with aromatic fluids

The flash point of biofuels and petroleum fuels is an essential safety-related property for fuel processing, transportation and storage. Hydroprocessed renewable diesel (HRD-76) and synthesized isoparaffin (SIP), two biofuel blend stocks, were blended with commercial petroleum aromatic fluids (aromatic 100, 150 and 200) to investigate the impacts of aromatics on biofuel flash point and to formulate blends with identical flash point characteristics as NATO F-76 marine diesel and JP-5 jet fuel. To overcome the complexity of the fuel blends, COSMO-RS (“conductor like screening model for realistic solvation”) was employed to predict the flash point of these biofuel + aromatic systems. COSMO-RS calculated the flash point of alkanes and aromatics present in biofuel and petroleum fuels and the flash point of SIP + aromatics binary mixture systems. Based on the pure compound and binary mixture predictions, COSMO-RS calculations were expanded to develop surrogate mixtures for biofuels and aromatic fluids. The surrogates were in turn utilized to predict the flash point of biofuel blends with aromatics and to formulate blends with the same flash point as petroleum fuels. The COSMO-RS calculation also assisted the selection of aromatics suitable for blending with different biofuels.

Insight into interaction mechanisms of binary mixture systems of explosion products (H2O, CO2, and N2) at extreme high pressures and temperatures

We performed ab initio molecular dynamics simulations to study interaction mechanisms of binary mixture systems of explosion products (H2O, CO2, and N2) under high temperatures and pressures. It is found that there is no reactions in the CO2N2 system at extreme conditions. Only at 4000 K and 50 GPa, the mixture of H2O and N2 began to decompose. The H2O and CO2 mixture can readily react and ultimately form different reaction products even at a relatively low temperature and pressure in contrast with the above two mixtures. The temperature plays a negative effect on the interaction in the H2OCO2 system.