Properties Of Binary Mixtures Research Articles

A study on thermophysical properties of binary mixtures of n-hexane with benzene and some alkyl-substituted benzenes within temperature range (293.15–323.15) K: Experimental and modeling approach

The current work reports densities and sound speeds, and related thermodynamic excess properties, namely excess molar volumes and excess isentropic compressibilities, measured at temperatures from (293.15 to 323.15) K and under atmospheric pressure conditions for binary mixtures of n-hexane with benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. Redlich-Kister polynomial correlated the thermodynamic excess properties to test the quality of experimental data. Excess properties contributed to understanding molecular interactions between involved molecules and the peculiarities of their packing in the mixture. The Jouyban-Acree model was used to correlate the mixtures' experimental densities, sound speeds, and their related derived properties, namely isobaric thermal expansivities and isentropic compressibilities. The average absolute percentage deviation of the correlated values from the experimental ones was better than 0.036 %, 0.058 %, 0.040 %, and 0.146 % for density, sound speed, isobaric thermal expansivity, and isentropic compressibility, respectively, attesting to the robustness of the Jouyban-Acree correlations. Additionally, the Perturbed Chain Statistical Associating Fluid Theory Equation of State modeled the densities of the current mixtures. Schaaff's Collision Factor Theory and Nomoto's relation were compared for their ability to model the sound speeds of the mixtures. The efficacy of these models was tested by computing the average absolute percentage deviations between experimental and computed values. The modeled densities are reasonably concordant with experimental data, with an overall deviation of 0.02 %. Notably, Nomoto's relation exhibited superior performance over Schaaff's theory in modeling sound speeds of current mixtures, with an overall deviation of 0.33 %. The current findings underline the efficacy and versatility of the used models for thermodynamic modeling in systems of varying complexity.

Turbulent Rayleigh–Bénard convection in a supercritical [formula omitted]-based binary mixture with cross-diffusion effects

CO2-based binary mixtures are promising in energy engineering to improve efficiencies of thermodynamic cycles where supercritical CO2 prevails. Indeed, under supercritical pressure and transcritical temperature conditions, special thermophysical properties of binary mixtures make the heat transfer process accompanied by enhanced cross-diffusion effects, i.e., the Soret effect and the Dufour effect. Their influences on heat transfer have not been well understood yet. This paper numerically investigates turbulent Rayleigh–Bénard convection in CO2-C2H6 binary mixture. Calculations are performed based on a spectral element method solver considering various temperature differences and pressures. Results indicate that the flow field presents a double-vortex structure. The thickness of the boundary layer is negatively correlated with the flow intensity. Under a positive separation ratio, the concentration gradient induced by cross-diffusion effects enhances buoyancy, which in turn reinforces the natural convection and heat transfer. The enhancement becomes stronger as the critical pressure is approached. Turbulent fluctuations are also strengthened by cross-diffusion effects, except for temperature fluctuations. The unusual reduction in temperature fluctuations is attributed to the increased size of the thermal plume caused by the Dufour effect.

Study on the molecular interactions of binary mixtures of N-methyl benzyl amine with halo methane’s through thermodynamic properties and correlation with the Jouyban–Acree model

ABSTRACT The thermodynamic and transport properties of binary mixtures of N-methyl benzyl amine (NMBA) with halo methane compounds at temperatures from 303.15 K to 313.15 K were investigated. The study analysed the excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy for activation of viscous flow using measured densities (ρ), viscosities (η), and speeds of sound (u). The research also examined the impact of the inductive effect on excess properties concerning intermolecular attractive forces between the respective constituents. Furthermore, the Jouyban–Acree model was employed to correlate density, speed of sound, and viscosity with composition and obtained good agreement.

Single Cationic Conduction Under Anion-Blocking Conditions in Sodium Ionic Liquids: Na[((FSO2)2N) x ((CF3SO2)(FSO2)N)1−x ]

There is a demand for low-melting-point molten-salt electrolytes with high thermal and electrochemical stability for the development of high-performance sodium-ion batteries. Mixing sodium bis(fluorosulfonyl)amide (NaFSA) and sodium (fluorosulfonyl)(trifluoromethylsulfonyl)amide (NaFTA) results in a large depression in their melting points. In this study, the phase behavior and Na+ transport properties of binary mixtures of NaFSA and NaFTA were investigated. The mixture of NaFSA and NaFTA with a molar ratio of 8:2 has a melting temperature (T m) of 363 K, successfully achieving an ionic liquid consisting of single cationic (Na+) salts. This mixture easily forms a super-cooled liquid. The ionic conductivity (σ) of Na[(FSA)0.8(FTA)0.2] continuously varied from above T m to below T m, obeying the Vogel–Tamman–Fulcher equation, which coincides with its super-cooling nature. The ionic conductivity and apparent Na+ transference number (t Na+) under anion-blocking conditions at T m approached 10−3 S cm−1 and 0.92, respectively.

FT-IR studies and excess thermodynamic properties of binary mixtures at various temperatures and correlation with the Jouyban–Acree model

ABSTRACT Densities (ρ), speeds of sound (u), and viscosities (η) for three binary mixtures of 4-Hydroxy-4-methyl-pentan-2-one with 3-amino-propan-1-ol, 2-amino-2-methyl-propan-1-ol, and 1-amino propan-2-ol were calculated at temperatures ranging from 303.15 to 313.15 K and atmospheric pressure over the entire composition range. Experimental measurements were used to calculate the excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of the activation of viscous flow. Partial molar properties and infinite dilution molar partial properties are also calculated for each binary system. Heteroassociates molecules forming complexes and chemical forces with specific interactions can be discussed from the results. The Prigogine–Flory–Patterson theory is used to identify the most important interaction. The results of the Jouyban–Acree model are discussed in terms of the mean relative deviation and individual relative between the calculated and experimental densities, speed of sound, and viscosities as an accuracy criterion. FTIR studies confirm the experimental findings of the investigated mixtures.

Studies on thermodynamics properties of binary mixtures of amyl acetate with propanol at T = 298.15 K to 318.15 K

The thermophysical properties of amyl acetate and isomers of propanol are critical for a variety of industrial, scientific, and safety–related applications. The density (ρ), viscosity (η), speed of sound (u), and refractive index (nD) of binary amyl acetate (1) + propanol (2) mixtures were measured at T = 298.15 K–318.15 K and pressure of 0.1 MPa. The excess molar volume (VmE), deviation in viscosity (Δη), deviation in speed of sound (Δu), excess isentropic compressibility (κsE), and deviation in refractive index (ΔnD) were derived from measured data. The deviation parameters in binary mixtures are affected by H–bonding, interstitial accommodation, and dipole–dipole interactions. The VmE, Δη and κsE values were described with Graph theory, Prigogine-Flory-Patterson (PFP) theory, Singh model, and ab–initio approach. While the VmE and Δη rise with increment in temperature whereas Δu and ΔnD decrease with increase in temperature.

Probe into the volumetric properties of binary mixtures: Essence of regression-based machine learning algorithms

Evaluating the volumetric properties of the binary mixtures is always a cumbersome and tedious task as the volumetric properties are sensitive towards the environmental conditions. The present novel work aims to predict the volumetric properties of different binary mixtures using regression-based machine learning algorithms. Four different machine learning algorithms are employed for making the surrogate models, namely, Gradient Boosting Machine (GBM), Stacked Ensemble (SE), Random Forest (RF), and Extremely Randomized Trees (XRT) for predicting the density, ultrasonic speed, viscosity, deviation in ultrasonic speed, deviation in viscosity, and excess molar volume of the binary mix made up of p-chlorotoluene and methanol. The accuracy of the algorithms is evaluated using the statistical tools over the predicted and the actual values. The machine learning algorithms can successfully predict the volumetric properties of the mix with GBM as the best and XRT as the worst amongst the models studied. After that, the surrogate models are also built to predict the properties of the different binary mixtures, namely, 2-chlorotoluene and n-hexane, 4-chlorotoluene and n-hexane, 1,3-dichlorobenzene and n-hexane, 2-chlorotoluene and 1,4-dioxane, 4-chlorotoluene and 1,4-dioxane, 1,3-dichlorobenzene and 1,4-dioxane, 2-chlorotoluene and methanol, 2-chlorotoluene and ethanol, 2-chlorotoluene and cyclohexane, 4-chlorotoluene and cyclohexane, and 1,3-dichlorobenzene and cyclohexane. For all the binary mixtures studied, GBM is found to be the most accurate algorithm for predicting the properties. Density is found to be sensitive towards the temperature, whereas remaining properties towards the mole fraction.

Study of Thermophysical Properties of Binary Mixtures of 1,4-Butanediol + Cresols at Different Temperatures

Density (ρ) and ultrasonic velocity (u) of liquid binary mixtures of 1,4-butanediol (1,4-BD), o-cresol (OC), m-cresol (MC) and p-cresol (PC) have been measured at four distinct temperatures (303.15 K, 308.15 K, 313.15 K and 318.15 K) as a function of composition. Using data, significant thermodynamic and thermophysical parameters viz., internal pressure-IP (πi), free volume-FV (Vf), enthalpy-EH (H), entropy-ET (Ts) and their excess counterparts have been evaluated. The excess parameter functions EFV (VfE), EEH (HE), EFE (GE) and EET (TsE) were observed to be primarily negative, while πiE is positive indicating that the constituent molecules in these mixtures have discernible interactions with one another.

Mixing twist-bend and ferroelectric nematic liquid crystals.

Twist-bend (N_{tb}) and ferroelectric (N_{F}) nematic liquid crystals exhibit several novel effects and new physical properties. Here, we report experimental studies on the phase diagram and some physical properties of binary mixtures of CB9CB and RM734 mesogens. Both N-N_{tb} and N-N_{F} phase transition temperatures and the corresponding enthalpies decrease significantly and, eventually, these transitions disappear at some intermediate compositions, stabilizing wide nematic phase (N). Temperature-dependent birefringence several degrees above the N-N_{tb} phase transition shows strong director tilt fluctuations. The critical range of the fluctuations increases with the nematic range and the critical exponent is consistent with the mean field. The spontaneous polarization of RM734 decreases drastically with the addition of CB9CB mesogen. The temperature dependence of the splay elastic constant of the mixtures' high-temperature nematic (N) phase strikingly differs from that of the pristine CB9CB and RM734 mesogens. The study shows that a small inclusion of either compound has a substantial effect on the phase diagram and physical properties.

Insight into the Molecular Mechanism of Surface Interactions of Phosphatidylcholines─Langmuir Monolayer Study Complemented with Molecular Dynamics Simulations.

Mutual interactions between components of biological membranes are pivotal for maintaining their proper biophysical properties, such as stability, fluidity, or permeability. The main building blocks of biomembranes are lipids, among which the most important are phospholipids (mainly phosphatidylcholines (PCs)) and sterols (mainly cholesterol). Although there is a plethora of reports on interactions between PCs, as well as between PCs and cholesterol, their molecular mechanism has not yet been fully explained. Therefore, to resolve this issue, we carried out systematic investigations based on the classical Langmuir monolayer technique complemented with molecular dynamics simulations. The studies involved systems containing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) analogues possessing in the structure one or two polar functional groups similar to those of DPPC. The interactions and rheological properties of binary mixtures of DPPC analogues with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and cholesterol were compared with reference systems (DPPC/POPC and DPPC/cholesterol). This pointed to the importance of the ternary amine group in PC/cholesterol interactions, while in PC mixtures, the phosphate group played a key role. In both cases, the esterified glycerol group had an effect on the magnitude of interactions. The obtained results are crucial for establishing structure-property relationships as well as for designing substitutes for natural lipids.

Volumetric, acoustic, and optical properties of binary mixtures of diethyl ether with alkanol at T = 293.15 K to 303.15 K

Density (ρ), ultrasonic speed (u), and refractive index (nD) of binary liquid mixtures such as diethyl ether (DEE) (1) + alkanol (isomers of propanol and 1-butanol) (2) were experimentally measured at T = 293.15 K to 303.15 K and at 0.1 MPa pressure. By using these measurements excess molar volume (VmE), deviation in ultrasonic speed (Δu), excess isentropic compressibility (κsE), and deviation in refractive index (ΔnD) were computed and associated with the Redlich-Kister polynomial equation. It was found that deviation parameters are influenced by H–bonding, interstitial accommodation, and dipole–dipole molecular interactions between binary mixtures. The VmE values have been interpreted by the Prigogine–Flory–Patterson (PFP) theory and the Flory–Treszczanowicz–Benson (FTB) model. The FTB model and PFP theory anticipated the VmE curves and were able to depict the perfect shape and magnitude of VmE values. The numeric values of u and nD were computed by using several empirical correlations and mixing rules. This study discusses the comparative significance of these relationships with the measured values of u and nD.

FT-IR studies and excess thermodynamic properties of binary mixtures of propargyl alcohol and amino alcohols at different temperatures and correlation with the Jouyban–Acree model

ABSTRACT Densities (ρ), speeds of sound (u), and viscosities (η) for three binary mixtures of propargyl alcohol with 3-amino-propan-1-ol, 2-amino-2-methyl-propan-1-ol, and 1-amino propan-2-ol were calculated at temperatures ranging from 303.15 to 313.15 K and atmospheric pressure over the entire composition range. Experimental measurements are used to calculate the excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of the activation of viscous flow. Partial molar properties and infinite dilution molar partial properties are also calculated for each binary system. The Prigogine-Flory-Patterson theory is used to identify the most important interaction. The results of the Jouyban-Acree model are discussed in terms of the mean relative deviation and individual relative between the calculated and experimental densities, speed of sound, and viscosities as an accuracy criterion. FTIR studies have also been added to confirm the experimental findings of the investigated mixtures.

Thermodynamic properties of binary mixtures of methyl acetate and some selected ketonesat varying compositions and temperatures

Density and viscosity measurements of binary mixtures of methyl acetate with propanone, butan-2-one and pentan-2-one were carried out at varying compositions (0 to 1) of methyl acetate and temperatures of 25, 30, 35 and 40◦C. The experimental data obtained were correlated with the Redlich-Kister polynomial equation from where excess molar volumes (VE ), excess viscosities (ηE), excess Gibbs free energies of activation for viscous flow (ΔG*E ), fitting coefficients and standard deviations of the mixtures were calculated. The ηE values were positive for mixtures of butan-2-one and pentan-2-one at all compositions and temperatures but gradually decrease with increasing composition and temperature. The mixtures of methyl acetate with propanone showed negative values of excess viscosity at all compositions of methyl acetate. The negative values are observed to be directly proportional to temperature. The values of VE for mixtures of methyl acetate + propanone system display positive deviations at lower compositions (0-0.4) and negative for higher mole fractions. The excess molar volumes of mixtures of butan-2-one and pentan-2-one are negative at the studied compositions and temperatures with a minimum at 0.3 composition and subsequent gradual decrease in negativity with increasing composition. The excess Gibbs free energy of activation for viscous flow (ΔG*E ) are positive at all compositions and temperatures and reaches a maximum at 0.3 composition above which it decreases. These results have been interpreted on the basis of the type and nature of interactions as well as differences in molecular architecture between the solvent mixtures.

Thermodynamic Properties of Binary Mixtures Containing Ionic Liquid 1-Butyl-3-methylimidazolium Thiocyanate and Ethanolamines at Different Temperatures: Measurement and PC-SAFT Modeling

Thermodynamic Properties of Binary Mixtures Containing Ionic Liquid 1-Butyl-3-methylimidazolium Thiocyanate and Ethanolamines at Different Temperatures: Measurement and PC-SAFT Modeling

Volumetric, Optical and Spectroscopic Properties of Binary Mixtures of Glycerol with Butanediol Isomers

Volumetric, Optical and Spectroscopic Properties of Binary Mixtures of Glycerol with Butanediol Isomers

Research on the thermodynamic properties of binary mixtures containing R1234ze(E) based on Helmholtz model

R1234ze(E) has excellent environmental protection properties, but the unsatisfactory latent heat of vaporization and volumetric cooling capacity impede its application. A mixture with excellent thermophysical properties and environmental performance can be obtained through blending R1234ze(E) with other working fluids. In this paper, the vapor-liquid equilibrium data of R1234ze(E)/R32, R1234ze(E)/R152a, R1234ze(E)/R290, and R1234ze(E)/R161 were correlated by Helmholtz equation of state combined with the mixing rule, and the calculation model of thermodynamic properties was established. On this basis, temperature glides, latent heats of vaporization, saturated vapor pressures, and other thermodynamic properties of binary mixtures containing R1234ze(E) were calculated and compared. The results indicate that the standard boiling points and critical temperatures of the four binary mixtures containing R1234ze(E) were similar to those of R22 in most mass concentration ranges. And their saturated vapor pressures at 298.15 K were all lower than that of R22 except for R1234ze(E)/R32 mixed in a few proportions. The latent heat of vaporization and specific heat capacity at a constant pressure of the four mixtures were larger than those of R1234ze(E) and adding the four pure refrigerants with excellent thermodynamic properties into R1234ze(E) helps to improve the latent heat of vaporization and specific heat capacity of the binary mixtures. Among the four mixtures, R1234ze(E)/R290 is an azeotropic mixture and R1234ze(E)/R152a is a non-azeotropic mixture. Finally, the recommended mixing ratios of R1234ze(E)/R32, R1234ze(E)/R152a, R1234ze(E)/R290, and R1234ze(E)/R161 to replace R22 were in the range of 0.56/0.44∼0.76/0.24, 0.58/0.42∼0.71/0.29, 0.27/0.73∼0.85/0.15, and 0.58/0.42∼0.84/0.16.

Volumetric, transport and acoustic properties of binary mixtures containing alkanol at 298.15–318.15 K

The measurement of density (ρ), viscosity (η) and ultrasonic speed (u) have been conducted at T = 298.15 K–318.15 K and at 0.1 MPa to study the intermolecular interactions between p–chlorotoluene with alkanol (C1–C2). These data were utilized to derive the excess properties like excess molar volume (VmE), deviation in viscosity (Δη), excess free energy of activation (ΔG*E), deviation in ultrasonic speed (Δu), and excess isentropic compressibility (κsE) for binary mixtures. Utilizing the VmE values, partial molar volume and excess partial molar volume were calculated. The Δη and κsE were investigated using theoretical models such as the Singh model and ab initio approach, which yielded interactional parameters that not only indicate the extent of unlike interactions and depolymerization of self–associated alkanol but also predicts the Δη and κsE for these systems. The conclusions of the ab initio approach were further validated by the Singh model for viscosity. The u data were further interpreted by various correlations and theories. Regarding correlation, Nomoto’s correlation demonstrated high predictive power for ultrasonic speed data, respectively, compared to other correlations. The resulting excess properties were fitted to Redlich–Kister polynomial equations. The VmE values were observed to be negative for p–chlorotoluene + alkanol systems at all temperatures. The study of the binary mixtures is significant because it sheds light on the nature of intermolecular interactions which has practical implications in areas such as chemical synthesis, solvent selection, and understanding the effects of solvents on reaction rates and product yields.

Machine learning-assisted modeling study on the density and heat capacity of ionic liquid-organic solvent binary systems

Properties of ionic liquids (ILs) play a crucial role in solvent design, process design, and process simulation for their various industrial applications. However, ILs come in a wide range of varieties, and obtaining their properties solely through experiments is a time-consuming and expensive process. Therefore, the development of predictive models capable of reliably estimating the properties of these compounds is essential for their effective industrial utilization. In this work, a hybrid model that combines the group contribution method with machine learning algorithms is proposed to predict two important properties (density and heat capacity) of ILs-organic solvent binary systems. This model establishes relationships between the properties and factors such as temperature, pressure, and molecular structure. The predictive performance of three machine learning methods, namely ANN, XGBoost, and LightGBM, is compared using 2504 heat capacity data points and 34,754 density data points, respectively. The results demonstrate that all three algorithms can provide accurate predictions, with the ANN model exhibiting the best performance. For heat capacity, the ANN model achieves a mean absolute error (MAE) of 0.0557 and a squared correlation coefficient (R2) of 0.9952. Regarding density, the ANN model yields a MAE of 0.0049 and an R2 of 0.9942 for the test dataset. Furthermore, the SHAP (Shapley Additive Explanations) method is employed to analyze the importance of each structure and parameter in the prediction results. The analysis reveals that the mole fraction of IL in the binary system has the most significant positive impact on the predicted properties. The models developed in this work not only provide accurate predictions for the properties of binary mixtures but also establish a data-driven framework for predicting the physicochemical properties of multicomponent mixtures.

Predicting soil hydraulic properties for binary mixtures – concept and application for constructed Technosols

Abstract. Constructed Technosols are an important means of substituting natural soil material, such as peat and geogenic material, for use in urban green infrastructure. One characteristic of Technosols important to their role in urban green infrastructure, specifically with respect to urban water management, is their soil hydraulic properties (SHPs). The SHPs depend on the composition of the constructed Technosols (e.g. their components and their mixing ratio). The diversity of possible components and the infinite number of mixing ratios practically prohibit the experimental identification of the composition needed to achieve suitable soil hydrological functions. In this study, we propose a compositional model for predicting the water retention curves (WRCs) of any binary mixture based on the measured WRCs of its two pure components only (basic scheme) or with one additional mixture (extended scheme). The unsaturated hydraulic conductivity curves (HCCs) are predicted based on the modelled WRCs. The compositional model is developed from existing methods for estimating the porosity of binary mixtures. The model was tested on four data sets of measured WRCs of different binary mixtures. The distribution of water and air in 50 cm high soil columns filled with these mixtures was predicted under hydrostatic conditions in order to assess their suitability for typical urban applications. The difference between the maxima of the pore size distributions ΔPSDmax (m) of the components indicates the applicability of the compositional approach. For binary mixtures with small ΔPSDmax, the water content deviations between the predicted and the measured WRCs range from 0.004 to 0.039 cm3 cm−3. For mixtures with a large ΔPSDmax, the compositional model is not applicable. The prediction of the soil hydraulic properties of any mixing ratio facilitates the simulation of flow and transport processes in constructed Technosols before they are produced (e.g. for specific urban water management purposes).

Thermophysical properties of binary mixtures of diethyl ether as oxygenate with cyclohexane and aromatic hydrocarbons

Density (ρ), speed of sound (u), and refractive index (nD) were measured for the binary mixture of diethyl ether (1) + cyclohexane, benzene, and toluene (2) systems at T= (288.15 K to 298.15 K) and 0.1 MPa. The measured data were utilized to calculate excess molar volume (VmE), deviation in ultrasonic speed (Δu), and deviation in refractive index (ΔnD). Our results illustrate that the positive value of VmE and negative value of Δu for diethyl ether + cyclohexane indicate the absence of specific interaction owing to the inert nature of cyclohexane and disruption of the dipole–dipole interactions in diethyl ether during mixing. Conversely, in diethyl ether + benzene or toluene system, the negative values of VmE and positive values of Δu suggest the presence of electron donor–acceptor interactions between the oxygen atom of diethyl ether and the π- electrons of benzene and toluene. These findings were further corroborated by the behavior of the molecular association parameter (MA), which showed that toluene exhibited the greatest value of MA and lower value of VmE compared to benzene, indicating a stronger degree of molecular association due increase in π-electron density because of the presence of electron-donating methyl group in toluene. On the other hand, cyclohexane showed the lowest value of MA, suggesting the disruption of dipole–dipole interaction in diethyl ether. Schaff’s collision factor theory demonstrated high predictive power for ultrasonic speed compared to other models. These experimental data significantly impact advancing theoretical models, process design, material development in chemical industries, and our understanding of the basic behavior of mixtures across various scientific and technical domains.