Search

Chapman–Enskog theory has long provided an accurate description of the transport properties of dilute gas mixtures. At elevated densities, revised Enskog theory (RET) provides a framework for describing the departure of the transport properties from their dilute-gas values. Various methods of adapting RET for the description of real fluids have been proposed in the literature. The methods have in common that they incorporate one or more length scales to describe molecular interactions. With few exceptions, the required length scales have been estimated from experimental transport property data. In this work, we introduce two transfer lengths that describe the residual transport of momentum and energy. We derive a model called the exchange-weighted closest approach (EWCA), which links the transfer lengths to the intermolecular potential. Combining the EWCA model with Mie potentials fitted to experimental equilibrium properties yields accurate predictions for several real fluids, including a binary mixture. At higher temperatures, the theory is accurate at surprisingly high densities, even up to the liquid–solid transition of argon. We demonstrate how the transfer lengths can be computed from experimental data or correlations for the transport properties. The transfer lengths obtained in this manner are in good agreement with those obtained from the EWCA model paired with an accurate ab initio potential for argon. The results suggest that kinetic theory, after further developments, can become a predictive theory also for liquids. [ABSTRACT FROM AUTHOR]

We assume that two parallel plates are immersed in a binary fluid mixture lying in the one-phase region near the demixing critical point and that the surface of each plate attracts the mixture components differently via short-range interactions. It is known that the composition inhomogeneity caused by the difference can induce a force exerted on the plate at equilibrium. In the present study, we investigate how a temperature gradient imposed vertically on the plates changes the induced force by calculating the composition profile subject to the Soret effect. Numerically solving the derived differential equation, we show that a temperature gradient within the critical regime can change the force distinctly from its equilibrium value and can make the force direction opposite to the one at equilibrium. [ABSTRACT FROM AUTHOR]

We theoretically study the evaporation-driven phase separation of a binary fluid mixture in a thin film deposited on a moving substrate, as occurs in meniscus-guided deposition for solution-processed materials. Our focus is on the limit of rapid substrate motion where phase separation takes place far away from the coating device. In this limit, demixing takes place under conditions mimicking those in a stationary film because substrate and film move at the same speed. We account for the hydrodynamic transport of the mixture within the lubrication approximation. In the early stages of demixing, diffusive and evaporative mass transport predominates, consistent with earlier studies on evaporation-driven spinodal decomposition. In the late-stage coarsening of the demixing process, the interplay of solvent evaporation, diffusive, and hydrodynamic mass transport results in several distinct coarsening mechanisms. The effective coarsening rate is dictated by the dominant mass transport mechanism and therefore depends on the material properties, evaporation rate, and time: slow solvent evaporation results in initially diffusive coarsening that for sufficiently strong hydrodynamic transport transitions to hydrodynamic coarsening, whereas rapid solvent evaporation can preempt and suppress hydrodynamic and diffusive coarsening. We identify a novel hydrodynamic coarsening regime for off-critical mixtures, arising from the interaction of the interfaces between solute-rich and solute-poor regions in the film with the solution–gas interface. This interaction induces a directional motion of solute-rich droplets along gradients in the film thickness, from regions where the film is relatively thick to where it is thinner. The solute-rich domains subsequently accumulate and coalesce in the thinner regions. [ABSTRACT FROM AUTHOR]

Transverse collective excitations in 50-50 and 80-20 Lennard-Jones binary liquid mixtures are studied for different mass ratio of components R at fixed numerical densities. Increasing the mass ratio results in a growing difference between frequencies of shear waves and transverse optic modes. We report an increase in the propagation gap width for shear waves with mass ratio of components and compare it to the gap width expression, known from the transverse dynamics of simple liquids. A four-variable dynamic model of transverse dynamics in binary liquids with an account of cross correlations between total-mass and mass-concentration transverse current fluctuations is solved analytically in the long-wavelength region. An equation for the propagation gap of shear waves for binary liquids is reported and analyzed. [ABSTRACT FROM AUTHOR]

We present results from the molecular dynamics simulation of surface-directed spinodal decomposition in binary fluid mixtures (A + B) with off-critical compositions. The aim is to elucidate the role of composition ratio in the early time wetting kinetics under the influence of long-range surface potential. In our simulations, the attractive part of surface potential varies as V(z) = −ϵa/zn, with ϵa being the surface-potential strength. The surface prefers the "A" species to form the wetting layer. Its thickness [R1(t)] for the majority wetting (number of A-type particles [NA] > number of B-type particles [NB]) grows as a power-law with an exponent of 1/(n + 2). This is consistent with the early time kinetics in the form of potential-dependent growth present in the Puri–Binder model. However, for minority wetting (NA < NB), the growth exponent in R1(t) is less than 1/(n + 2). Furthermore, on decreasing the field strength ϵa, we recover 1/(n + 2) for a minority wetting case. We provide phenomenological arguments to explain the early time wetting kinetics for both cases. [ABSTRACT FROM AUTHOR]

An azeotrope is a constant boiling point mixture, and its behavior is important for fluid separation processes. Predicting azeotropes from atomistic simulations is difficult due to the complexities and convergence problems of Monte Carlo and free-energy perturbation techniques. Here, we present a methodology for predicting the azeotropes of binary mixtures, which computes the compositional dependence of chemical potentials from molecular dynamics simulations using the S0 method and employs experimental boiling point and vaporization enthalpy data. Using this methodology, we reproduce the azeotropes, or lack thereof, in five case studies, including ethanol/water, ethanol/isooctane, methanol/water, hydrazine/water, and acetone/chloroform mixtures. We find that it is crucial to use the experimental boiling point and vaporization enthalpy for reliable azeotrope predictions, as empirical force fields are not accurate enough for these quantities. Finally, we use regular solution models to rationalize the azeotropes and reveal that they tend to form when the mixture components have similar boiling points and strong interactions. [ABSTRACT FROM AUTHOR]

The lifetime of a hydrogen bond between water and dimethyl sulfoxide (DMSO) is found to be considerably longer than that between two water molecules in neat water. This is counter-intuitive because the charge on the oxygen in DMSO is considerably less than that in water. Additionally, the strength of the water–dimethyl sulfoxide (w–D) hydrogen bond is found to be strongly composition dependent; the lifetime of the hydrogen bond is ten times larger at 30% than at very low concentrations. Using computer simulations, we perform microscopic structural and dynamic analysis to find that these anomalies arise at least partly from an "action-at-a-distance" effect where the attraction between the hydrophobic methyl groups results in the self-aggregation of DMSO molecules that "cages" both the rotational and linear motions of the molecules involved. This is reflected in the observed strong correlation of the lifetime with the local coordination number of the associated methyl groups. The elongated w–D h-bond lifetime causes a slowdown of collective dynamics and affects the lifetime of the w–w h-bond. This nonlinear feedback mechanism explains the strong composition dependence of viscosity and is anticipated to play a dominant role in many self-assemblies. Furthermore, the w–D hydrogen bond breaking mechanism changes from low to high DMSO concentration, a phenomenon not anticipated a priori. We introduce a new order parameter-based free energy surface of the bond breaking pathway. A two-dimensional transition state rate theory calculation is performed for the lifetime of the w–D h-bond that is found to be semi-quantitatively accurate. [ABSTRACT FROM AUTHOR]

The development of new materials typically involves a process of trial and error, guided by insights from past experimental and theoretical findings. The inverse design approach for soft-matter systems has the potential to optimize specific physical parameters, such as particle interactions, particle shape, or composition and packing fraction. This optimization aims to facilitate the spontaneous formation of specific target structures through self-assembly. In this study, we expand upon a recently introduced inverse design protocol for monodisperse systems to identify the required conditions and interactions for assembling crystal and quasicrystal phases within a binary mixture of two distinct species. This method utilizes an evolution algorithm to identify the optimal state point and interaction parameters, enabling the self-assembly of the desired structure. In addition, we employ a convolutional neural network (CNN) that classifies different phases based on their diffraction patterns, serving as a fitness function for the desired structure. Using our protocol, we successfully inverse design two-dimensional crystalline structures, including a hexagonal lattice and a dodecagonal quasicrystal, within a non-additive binary mixture of hard disks. Finally, we introduce a symmetry-based order parameter that leverages the encoded symmetry within the diffraction pattern. This order parameter circumvents the need for training a CNN and is used as a fitness function to inverse design an octagonal quasicrystal. [ABSTRACT FROM AUTHOR]

We perform molecular dynamics simulations of a binary mixture of water and trehalose with the TIP4P/Ice water model. We analyze the slow dynamics of trehalose molecules in the mildly supercooled region for concentrations of 3.66 and 18.57 wt. %. We previously studied the dynamics of water in the same mixtures. Supercooled TIP4P/Ice water solvating trehalose molecules was found to follow the Mode Coupling Theory (MCT) and to undergo a transition from a fragile to a strong behavior for both concentrations. Here, we show that also the dynamics of trehalose molecules follows the MCT and displays a fragile to strong crossover (FSC). The results show that trehalose in binary mixtures with water shares with it the dynamical behavior typical of glass forming liquids. Moreover, the FSC for trehalose structural relaxation times is found to occur at temperatures close to those previously obtained for water in the same solutions, showing that the dynamics of the solute is strongly coupled to that of the solvent. We also perform a MCT test showing that the trehalose dynamics obeys the MCT time–temperature superposition principle and that the exponents derived from the theory and the ones obtained from fitting procedure of the relaxation times are comparable, confirming that trehalose molecules in supercooled water solutions follow the MCT of glassy dynamics. Moreover, as predicted by the theory, trehalose particles have MCT parameters comparable to those of water in the same mixtures. This is an important result, given that MCT was originally formulated for monoatomic particles. [ABSTRACT FROM AUTHOR]

In experimental and theoretical studies of glass transition phenomena, one often finds a sharp crossover in dynamical properties at a temperature Tcr. A bifurcation of a relaxation spectrum is also observed at a temperature TB ≈ Tcr; both lie significantly above the glass transition temperature. In order to better understand these phenomena, we introduce a new model of glass-forming liquids, a binary mixture of prolate and oblate ellipsoids. This model system exhibits sharp thermodynamic and dynamic anomalies, such as the specific heat jump during heating and a sharp variation in the thermal expansion coefficient around a temperature identified as the glass transition temperature, Tg. The same temperature is obtained from the fit of the calculated relaxation times to the Vogel–Fulcher–Tammann (VFT) form. As the temperature is lowered, the calculated single peak rotational relaxation spectrum splits into two peaks at TB above the estimated Tg. Similar bifurcation is also observed in the distribution of short-to-intermediate time translational diffusion. Interrogation of the two peaks reveals a lower extent of dynamic heterogeneity in the population of the faster mode. We observe an unexpected appearance of a sharp peak in the product of rotational relaxation time τ2 and diffusion constant D at a temperature Tcr, close to TB, but above the glass transition temperature. Additionally, we coarse-grain the system into cubic boxes, each containing, on average, ∼62 particles, to study the average dynamical properties. Clear evidence of large-scale sudden changes in the diffusion coefficient and rotational correlation time signals first-order transitions between low and high-mobility domains. [ABSTRACT FROM AUTHOR]

We explore the phase behavior of a binary colloidal system under external spatially periodic modulation. We perform Monte Carlo simulations on a binary mixture of big and small repulsive Lennard-Jones particles with a diameter ratio of 2:1. We characterize structure by isotropic and anisotropic pair correlation functions, cluster size distribution, bond angle distribution, order parameter, and specific heat. We observe the demixing of the species in the absence of external modulation. However, the mixing of the species gets enhanced with increasing potential strength along with the alignment of the particles transverse to the modulation. The de-mixing order parameter shows discontinuity with increasing modulation strength, characterizing a first order phase transition. The peak in specific heat increases linearly with the size of the system. We also look into the dynamical behavior of the system via computing Mean Square Displacement (MSD) along both parallel and perpendicular directions to the modulation. We observe a decrease in the diffusion coefficient for both types of particles as we increase the strength of the modulation. [ABSTRACT FROM AUTHOR]

Phase separation plays a key role in determining the self-assembly of biological and soft-matter systems. In biological systems, liquid–liquid phase separation inside a cell leads to the formation of various macromolecular aggregates. The interaction among these aggregates is soft, i.e., they can significantly overlap at a small energy cost. From a computer simulation point of view, these complex macromolecular aggregates are generally modeled by soft particles. The effective interaction between two particles is defined via the generalized exponential model of index n, with n = 4. Here, using molecular dynamics simulations, we study the phase separation dynamics of a size-symmetric binary mixture of ultrasoft particles. We find that when the mixture is quenched to a temperature below the critical temperature, the two components spontaneously start to separate. Domains of the two components form, and the equal-time order parameter reveals that the domain sizes grow with time in a power-law manner with an exponent of 1/3, which is consistent with the Lifshitz–Slyozov law for conserved systems. Furthermore, the static structure factor shows a power-law decay with an exponent of 4, consistent with the Porod law. [ABSTRACT FROM AUTHOR]

Coarse-grained (CG) molecular models greatly reduce the computational cost of simulations allowing for longer and larger simulations, but come with an artificially increased acceleration of the dynamics when compared to the parent atomistic (AA) simulation. This impedes their use for the quantitative study of dynamical properties. During coarse-graining, grouping several atoms into one CG bead not only reduces the number of degrees of freedom but also reduces the roughness on the molecular surfaces, leading to the acceleration of dynamics. The RoughMob approach [M. K. Meinel and F. Müller-Plathe, J. Phys. Chem. B 126(20), 3737–3747 (2022)] quantifies this change in geometry and correlates it to the acceleration by making use of four so-called roughness volumes. This method was developed using simple one-bead CG models of a set of hydrocarbon liquids. Potentials for pure components are derived by the structure-based iterative Boltzmann inversion. In this paper, we find that, for binary mixtures of simple hydrocarbons, it is sufficient to use simple averaging rules to calculate the roughness volumes in mixtures from the roughness volumes of pure components and add a correction term quadratic in the concentration without the need to perform any calculation on AA or CG trajectories of the mixtures themselves. The acceleration factors of binary diffusion coefficients and both self-diffusion coefficients show a large dependence on the overall acceleration of the system and can be predicted a priori without the need for any AA simulations within a percentage error margin, which is comparable to routine measurement accuracies. Only if a qualitatively accurate description of the concentration dependence of the binary diffusion coefficient is desired, very few additional simulations of the pure components and the equimolar mixture are required. [ABSTRACT FROM AUTHOR]

We consider a binary mixture of chemically active particles that produce or consume solute molecules and that interact with each other through the long-range concentration fields they generate. We analytically calculate the effective phoretic mobility of these particles when the mixture is submitted to a constant, external concentration gradient, at leading order in the overall concentration. Relying on an analogy with the modeling of strong electrolytes, we show that the effective phoretic mobility decays with the square root of the concentration: our result is, therefore, a nonequilibrium counterpart to the celebrated Kohlrausch and Debye–Hückel–Onsager conductivity laws for electrolytes, which are extended here to particles with long-range nonreciprocal interactions. The effective mobility law we derive reveals the existence of a regime of maximal mobility and could find applications in the description of nanoscale transport phenomena in living cells. [ABSTRACT FROM AUTHOR]

We present comprehensive numerical results from a study of model H, which describes phase separation kinetics in binary fluid mixtures. We study the pattern dynamics of both density and velocity fields in d = 2, 3. The density length scales show three distinct regimes, in accordance with analytical arguments. The velocity length scale shows a diffusive behavior. We also study the scaling behavior of the morphologies for density and velocity fields and observe dynamical scaling in the relevant correlation functions and structure factors. Finally, we study the effect of quenched random field disorder on spinodal decomposition in model H. [ABSTRACT FROM AUTHOR]

We evaluate depletion forces in molecular dynamics simulation of a binary mixture of spheres (depleted particles) and rods (depletant particles) for a wide range of densities for both species. This evaluation was carried out using a recently proposed least squares fitting algorithm. We found that the restriction of the rods' rotational degrees of freedom, when the distance between two spheres is less than the rods length, creates a shallow, and apparently linear, attractive force ramp. For intersphere distances smaller than the rods' diameter, a much stronger attractive force is found, and a large repulsive barrier appears between these aforementioned regimes, roughly at the distance of the rods' thickness. The evaluated forces are validated via a comparison of the pairwise correlation functions obtained from molecular dynamics simulation of a mono-disperse sphere fluid, using the evaluated effective forces, against the original (full system) pairwise correlation functions. Agreement is excellent. We also record the angular pairwise correlation function, using the P2(x) Legendre polynomial, and find that for high densities of both species, a local nematic ordering starts to appear. This nematic order may be a factor in the small differences found between original and effective pairwise correlation functions at high densities of rods. [ABSTRACT FROM AUTHOR]

Liquid–liquid phase separation in diverse manufacturing and biological contexts often occurs in the presence of aggregated particles or complex-shaped structures that do not actively participate in the phase separation process, but these "background" structures can serve to direct the macroscale phase separation morphology by their local symmetry-breaking presence. We perform Cahn–Hilliard phase-field simulations in two dimensions to investigate the morphological evolution, wetting, and domain growth phenomena during the phase separation of a binary mixture in contact with model fractal aggregates. Our simulations reveal that phase separation initially accelerates around the fractal due to the driving force of wetting, leading to the formation of the target composition patterns about the fractals, as previously observed for circular particles. After the formation of a wetting layer on the fractal, however, we observe a dramatic slowing-down in the kinetics of phase separation, and the characteristic domain size eventually "pins" to a finite value or approaches an asymptotic scaling regime as an ordinary phase if the phase separation loses memory of the aggregates when the scale of phase separation becomes much larger than the aggregate. Furthermore, we perform simulations to examine the effects of compositional interference between fractals with a view to elucidating interesting novel morphological features in the phase-separating mixture. Our findings should be helpful in understanding the qualitative aspects of the phase separation processes in mixtures containing particle aggregates relevant for coating, catalyst, adhesive, and electronic applications as well as in diverse biological contexts, where phase separation occurs in the presence of irregular heterogeneities. [ABSTRACT FROM AUTHOR]

We investigated collision induced transitions in the (0, 0) band of the A2Σ+–X2Π electronic transition of nitric oxide (NO) using two-color polarization spectroscopy (TCPS). Two sets of TCPS spectra for 1% NO, diluted in different buffer gases at 295 K and 1 atm, were obtained with the pump beam tuned to the R11(11.5) and OP12(1.5) transitions. The buffer gases were He, Ar, and N2. The probe was scanned while the pump beam was tuned to the line center. Theoretical TCPS spectra, calculated by solving the density matrix formulation of the time-dependent Schrödinger wave equation, were compared with the experimental spectra. A collision model based on the modified exponential-gap law was used to model the rotational level-to-rotational level collision dynamics. A model for collisional transfer from an initial to a final Zeeman state was developed based on the difference in cosine of the rotational quantum number J projection angle with the z-axis for the two Zeeman states. Rotational energy transfer rates and Zeeman state collisional dynamics were varied to obtain good agreement between theory and experiment for the two different TCPS pump transitions and for the three different buffer gases. One key finding, in agreement with quasi-classical trajectory calculations, is that the spin-rotation changing transition rate in the A2Σ+ level of NO is almost zero for rotational quantum numbers ≥8. It was necessary to set this rate to near zero to obtain agreement with the TCPS spectra. [ABSTRACT FROM AUTHOR]

Benzyltoluene (BT) and dibenzyltoluene (DBT) mixtures are promising liquid organic hydrogen carriers (LOHCs) due to their high hydrogen storage capacity, excellent thermal stability and safety of storage and transportation. This study investigates the thermodynamic properties of BT + DBT mixtures to develop an accurate prediction model for hybrid LOHCs. Experimental measurements of liquid density were performed over a wide temperature range (293.15–433.15 K) and pressures up to 20 MPa, revealing the effects of temperature, pressure, and composition on thermodynamic properties. An empirical model using the Tait equation achieved an average absolute deviation of 0.027%. Drawing on experimental data, the model parameters of perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state (EoS) were optimized separately for low-pressure and high-pressure regions, improving prediction accuracy and enabling the evaluation of bubble-point pressure and saturated densities. Additionally, simulations were conducted to analyze the variation of hydrogen mole fraction with pressure and temperature in both the dehydrogenation reactor and the condenser. Derived thermodynamic properties, including excess molar volume, isothermal compressibility, thermal expansion coefficient, and heat capacity, were calculated to support LOHC system design. This work provides foundational data and a reliable theoretical model to optimize hydrogen storage and dehydrogenation processes for BT + DBT mixtures. The results offer valuable insights for future applications of LOHC technology in energy-efficient hydrogen storage and transport systems. • Liquid density of BT + DBT was measured at elevated temperatures and pressures. • Influence of mole fraction, temperature and pressure on density was elucidated. • SAFT-type EoSs were developed to predict the thermodynamic properties of BT + DBT. • Mole fraction of hydrogen in dehydrogenation facilities was discussed. [ABSTRACT FROM AUTHOR]

Recently, there has been increased attention on mixtures of H 2 , NH 3 , CO, and CH 4 , leading to a higher demand for suitable global reaction mechanisms (GRMs). Although some GRMs have been proposed for binary mixtures such as H 2 +CH 4 and H 2 +NH 3 , a suitable GRM for the complex mixture of H 2 +NH 3 +CO + CH 4 has yet to be established. This study investigated GRMs for each pure gas (H 2 , NH 3 , CO, and CH 4) and their corresponding mixtures. Results from detailed reaction mechanisms (DRMs) and selected experiments were used as references. First, a 2-step GRM for H 2 was developed to improve the prediction in the fuel-lean conditions and was used to improve GRMs for H 2 +NH 3. A more reliable 5-step GRM for H 2 +NH 3 was also developed, including the 2-step GRM for H 2 and a modified 3-step GRM for NH 3. Second, GRMs for H 2 +CO + CH 4 were investigated. A 1-step GRM for CH 4 was improved to account for the pressure variations. More reliable GRMs that combine the water gas shift reaction (CO + H 2 O → CO 2 +H 2) and the modified 3-step reactions for CH 4 were also proposed. Thus, two GRMs could be suggested for H 2 +CO + CH 4 : a 5-step GRM including the 1-step GRM for H 2 and a 6-step GRM including the 2-step GRM for H 2. Finally, optimized 8-step and 9-step GRMs for H 2 +NH 3 +CO + CH 4 were proposed, and reasonable LBVs could be predicted across a wide range of temperatures (300–600 K) and pressures (1–5 atm). The number of reactions could be selectively reduced based on the fuel compositions. • Global reaction mechanisms (GRMs) for H 2 +NH 3 +CO + CH 4 mixtures were investigated. • Laminar burning velocities from reaction mechanisms and experiments were compared. • GRMs were improved, including 2-step for H 2 , 5-step for NH 3 , and 6-step for CH 4. • Results were valid in the temperature (300–600 K) and pressure (1–5 atm). [ABSTRACT FROM AUTHOR]

Understanding the nanotransport properties of NH 3 and H 2 is critical for designing adsorption and separation materials. In this work, we develop a novel numerical model at the molecular level by incorporating the M − S approach and effective medium theory, and provide a rigorous and analyzable simulation implementation for a binary transport system of NH 3 and H 2. In addition, the effect of pore length nonuniformity is simultaneously incorporated. The results show that high temperatures and large radii are detrimental to adsorption but favorable for diffusion at the single-pore scale, while the greater conductance increase in large pores dominates the fluid transport property in the pore network. The existence of a pore length distribution can induce greater effective diffusivity and lower apparent tortuosity within the pore network. Moreover, we confirm that at 300 K, the equilibrium selectivity of NH 3 over H 2 reaches approximately 28 in a uniform pore network with a pore radius of 0.25 nm, indicating the feasibility of nanoporous silica materials for use in adsorption separation of NH 3 and H 2 mixtures. [Display omitted] • Numerical transport model of NH 3 /H 2 mixture is built based on the M − S theory. • Competitive effect of adsorption and diffusion of fluid in nanopore is analyzed. • Influence of pore length distribution on fluid transport is discussed. • Possible strategy of NH 3 /H 2 mixture separation by Nano-porous silica is proposed. [ABSTRACT FROM AUTHOR]

Throughout the hydrogen value chain, industries increasingly rely on digital tools utilizing equations of state to develop safer, more efficient, and cost-effective processes. This paper compares the Peng-Robinson equation of state with volume translation (tc-PR EoS) and the Coquelet-El Abbadi-Houriez equation of state (CAH EoS), modified with the Feymann-Hibbs correction to the covolume, to account for the quantum swelling phenomenon. The models were used to predict density, residual enthalpy, and Joule-Thomson coefficients over a temperature range of 20–353 K. It has been applied to binary mixtures relevant to the hydrogen industry, including H 2 /CO 2 , H 2 /CO, H 2 /CH 4 , and H 2 /N 2. Model parameters were fitted to liquid-vapor equilibrium (VLE) data using the generalized Wong-Sandler (g-WS) and van der Waals (vdW) classical mixing rules. The performance of the models in representing VLE data and densities over a wide range of thermodynamic conditions was assessed. These models can help design processes for hydrogen production, transport and use. [Display omitted] • Modelling pure hydrogen with tc-Peng-Robinson and Coquelet-El Abbadi-Houriez EoS. • Incorporating quantum swelling phenomenon with Aasen's covolume correction. • Predicting key thermodynamic properties of pure hydrogen using a cubic EoS. • Prediction of vapor-liquid equilibrium and binary mixture densities with hydrogen. • Comparison and adjustment of van der Waals and generalized Wong-Sandler mixing rules. [ABSTRACT FROM AUTHOR]

This study aimed to investigate in vitro antihypertensive property of protein hydrolysates from Pleurotus spp. mushrooms obtained through enzymatic hydrolysis. Flavourzyme™ 500 L, Alcalase™ 2.4 L and Neutrase™ 0.8 L were used alone and in combination using an experimental design of mixtures. Antihypertensive activity was determined by angiotensin-converting enzyme (ACE) inhibition and the simulated in vitro digestion was performed according to the INFOGEST protocol. Results showed that most of the protein hydrolysates obtained displayed higher ACE inhibitory activity than non-hydrolyzed protein, ranging from 15.76 % and 50.87 % inhibition. The highest ACE inhibition and the lowest TCA soluble protein content (52.09 %) were detected for the protein hydrolysates obtained by using the binary mixture of Flavourzyme™ 500 L and Alcalase™ 2.4 L in equal proportions. Hydrolysis kinetics showed no significant difference in ACE inhibitory activity between 20 and 120 minutes of enzymatic reaction. The fraction with molecular weight between 3 and 5 kDa obtained after ultrafiltration showed the most contribution for ACE inhibitory activity (47 % inhibition). After simulated digestion, the hydrolysates maintained a significant ACE inhibition capacity, indicating the resistance of the peptides to the action of gastrointestinal enzymes. Through proteomic analysis, 26 peptides were identified and the sequences LPILP, IPLLP, PLLPQ and VIQYDPPQ were considered potentially antihypertensive. [Display omitted] • Pleurotus spp. mushroom is a potential source of bioactive peptides. • Enzymatic hydrolysis increased ACE inhibitory activity of proteins from Pleurotus spp. mushroom. • Flavourzyme and Alcalase resulted in hydrolysates with the highest ACE inhibitory activity. • Fractions with molecular weight < 5 kDa exhibit the highest ACE inhibitory activity. • The protein hydrolysates maintained their antihypertensive potential after digestion. [ABSTRACT FROM AUTHOR]

This study investigated the molecular interactions within mixtures of 1-aminobutane and alkanol such as n–butanol, sec–butanol, and iso–butanol. Excess molar volume ($V_m^E$VmE), excess speed of sound (${u^E}$uE), and excess isentropic compressibility ($\kappa _s^E$κsE) were assessed using experimentally measured data of density ($\rho $ρ) and ultrasonic speed ($u$u) at the T = 298.15 K to 318.15 K and at pressure 0.1 MPa. Utilizing the $V_m^E$VmE values, the partial (${\bar V_i}$Vˉi) and apparent molar volume (${V_{\varphi i}}$Vφi) were also derived. The $V_m^E$VmE for these systems follow the pattern: n–butanol < iso–butanol < sec–butanol whereas the ${u^E}$uEorder for binary systems: n–butanol > iso–butanol > sec–butanol. As temperature increases, the become more negative, whereas the ${u^E}$uE values were less positive. The RK polynomial equation is employed to corroborate the computed excess and deviation property data. Furthermore, the $V_m^E$VmE and $\kappa _s^E$κsEvalues were interpreted by FTB model, PFP theory and ab-initio approach [ABSTRACT FROM AUTHOR]

Excess molar volume, excess isentropic compressibility, deviation in viscosity and excess Gibbs free energy of activation of viscous flow for binary mixtures of N,N-dimethyl benzyl amine with 2-methyl-1-butanol(P1), 2-pentanol (P2) and 2-methyl-2-butanol (P3) components selected compositions were determined from the measured values of densities (ρ), viscosities (n), and speeds of sound (u) of pure components and their mixtures from 303.15 K to 313.15 K. The results are analysed in terms of intermolecular interactions or hydrogen bonding or netero-association interactions in the binary mixtures. Finally, the Prigogine-Flory-Patterson (PFP) Theory is applied to identify the most predominant molecular interaction. Using the Jouyban-Acree model, results are discussed in terms of mean relative deviation (MRDs) and individual relative deviation (IRD) between calculated and experimental densities, speeds of sound and viscosities as an accuracy criterion. [ABSTRACT FROM AUTHOR]

In this paper, a method of ultrasound-assisted low-pressure closed acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS) analysis was proposed for trace element quantification in rock samples. By using 1.5 mL of a binary acid mixture of HNO3–HF with a ratio of 2:1, rock powder samples of 50 mg were completely decomposed in 12 h at 140 °C after 4 h of ultrasonic treatment with or without pressure relief procedure. The element extraction efficiency of this method was evaluated via the yielded relative errors (REs) of the trace elements in a series of geological standard reference materials (SRMs) with compositions from basic to acidic. It was found that the contents of trace elements (i.e., 36 metal elements from Li to U) in basalt BCR-2, diabase W-2a, andesite AGV-2, granodiorite GSP-2, and granite GSR-1 were comparable with the reported reference values, giving REs with absolute values less than 10%. It was also found that clear solutions without sample powder residues by naked-eye observation can be obtained when using the low-pressure closed decomposition method without ultrasonic pretreatment. The quantification results, however, were found to be negatively biased for most of the studied trace elements, and, in particular, the content bias of Zr in SRM GSP-2 was down to −86.28% due to the low extraction efficiency of refractory minerals of the low-pressure closed digestion method. By applying this proposed digestion strategy, the decomposition property of the ternary combination of HNO3–HF–mannitol in terms of trace element quantification accuracy was also investigated. Results showed that the concentrations of trace elements in the studied SRMs were consistent with the reference values, giving REs within ±6.94%, which revealed that there was no deterioration of extraction efficiencies of trace elements and neglected mass interferences from mannitol. This study demonstrated the essential role of ultrasound irradiation in rock sample decomposition to achieve the high extraction efficiency of trace elements under a low-pressure environment, and the developed approach with promising future applications in geoscience exhibited considerable merits, including a high extraction efficiency, feasible digestion process, less time consumption, and lower safety associated risks. [ABSTRACT FROM AUTHOR]

Excess molar volume, excess isentropic compressibility, deviation in viscosity and excess Gibbs free energy of activation of viscous flow for binary mixtures of dibenzyl amine with 1-pentanol (P1), 2-pentanol (P2) and 2-methyl-2-butanol (P3) components selected compositions were determined from the measured values of densities (ρ), viscosities (η), and speeds of sound (u) of pure components and their mixtures from 303.15 K to 313.15 K. The results are analysed in terms of complex formation through proton donor – acceptor interactions or hydrogen bonding or hetero molecular association interactions in the binary mixtures. Finally, the Prigogine–Flory–Patterson (PFP) Theory is applied to identify the most predominant molecular interaction. Jouyban-Acree model, results are discussed in terms of mean relative deviation (MRDs) and individual relative deviation (IRD) between calculated and experimental densities, speeds of sound and viscosities as an accuracy criterion. [ABSTRACT FROM AUTHOR]

Currently, recovery of organic solvents using eco‐friendly methods is one of the primary industrial tasks. Separation of liquid media by pervaporation offers more advantages as compared to conventional purification methods, such as distillation, in view of low energy and resource consumption. This work is focused on the study of novel copolyamide with 2‐pyridylquinoline‐4,7‐dicarboxylic acid moieties in the main chain and its metal‐polymer complex in the form of dense films. At present, metal‐polymer complexes are growing in importance among membranes. The analysis of mechanical and thermal properties of the films also supports their high operational characteristics. Comprehensive studies of the structure of the obtained films show that both samples have a rigid and dense structure, but the metal‐polymer complex is characterized by an increased surface roughness. The hypothesis of supramolecular association between polymers and separated liquids (methanol and toluene) is confirmed by quantum chemical calculations. Transport properties of novel polymers in pervaporation of toluene/methanol mixtures are examined and compared with the literature data. Both polymer films demonstrate an outstanding selectivity toward toluene in the separation of binary mixtures. The developed films have higher values of total flux and separation factor as compared to the most of known membranes. [ABSTRACT FROM AUTHOR]

Thermochromic sensors employing cholesteric liquid crystal droplets offer customizable temperature and spectral responses through molecular adjustments of nematic mesogens. Embedded in a polymer matrix, these portable sensors enable direct, reversible temperature visualization on the skin, demonstrating potential for advanced sensing applications. [Display omitted] Rapid and accurate detection and visualization of temperature variations near the human body hold significant importance. This study presents thermochromic colloids capable of adjusting the detectable temperature range and reflection wavelength over a wide spectrum. The systematic investigation focuses on understanding the influence of the molecular structure of nematic mesogens on the morphological dynamics of cholesteric liquid crystal droplets and their associated thermochromic behaviors. A tunable colorimetric temperature range (i.e., from 10 to 40 °C) and high sensitivity (i.e., Δ λ Δ T −1 > 100nm °C−1) are realized through precise modulation of the alkyl chain lengths in cyanobiphenyls molecules, combined with a cholesteryl oleyl carbonate as a chiral dopant. We demonstrate the efficiency of a binary mixture of different mesogens, enabling customized structural colors with desired temperature responses. Finally, inspired by the ability of the octopus to camouflage through the elongation or contraction of its pigment cells, thermochromic droplets are embedded within a polymer matrix, resulting in a portable skin patch that offers quick, reversible, and direct temperature visualization of the human body. [ABSTRACT FROM AUTHOR]

Hyperuniform states of matter exhibit unusual suppression of density fluctuations at large scales, contrasting sharply with typical disordered configurations. Various types of hyperuniformity emerge in multicomponent disordered systems, significantly enhancing their functional properties for advanced applications. This paper focuses on developing a theoretical framework for two-component hyperuniform systems. We provide a robust theoretical basis to identify novel conditions on structure factors for a variety of hyperuniform binary mixtures, classifying them into five distinct types with seven unique states. Our findings also offer valuable guidelines for designing multihyperuniform materials where each component preserves hyperuniformity, added to the overall hyperuniformity. [ABSTRACT FROM AUTHOR]

This paper develops a system–component integrated design method for a closed Brayton cycle in a nuclear-powered emergency power vehicle, optimizing the thermodynamic performance by varying the maximum operating temperature and pressure, minimum operating temperature, helium–xenon gas molar mass, and PCHE parameters to maximize the specific power and thermal efficiency. The key results are as follows: (1) The maximum allowable pressure decreases with the temperature, and the specific power increases for both the SRC and the IRC without considering the ultimate heat sink. (2) The PCHE weight is minimized at a helium–xenon gas molar mass of 25 g/mol, while the turbomachine's weight decreases with an increasing molar mass, leading to an overall system weight reduction. (3) The thermal efficiency decreases with lower minimum operating temperatures, optimizing at 350 K due to a precooler weight increase. (4) The thermal efficiency plateaus after a certain number of PCHE channels, with the recuperator effectiveness significantly impacting the performance. (5) The SRC, with a specific power and a thermal efficiency of 194.38 kW/kg and 39.19%, is preferred over the IRC for the SIMONS due to its mobility and rapid deployment. This study offers a comprehensive analysis for optimizing closed Brayton cycle systems in emergency power applications. [ABSTRACT FROM AUTHOR]

The aim of this study is to address the problems of oil mixing during the sequential transportation of refined oil and the influence of temperature on the quality detection of refined oil. To better detect the quality of refined oil, UV-Visible transmission spectroscopic experiments of 92# gasoline, diesel oil, and their mixtures at different temperatures are performed. Then, the influence of temperature on the transmission spectrum is analyzed, and the transmittance–temperature compensation equations are obtained. Based on the double-thickness inversion model, the optical constants of the mixed refined oil at UV-Visible wavelengths are obtained, and the effect of temperature on the optical constants is analyzed. For a specified optical range, the transmittance of the mixed refined oil gradually increases with increasing temperature. The temperature has a certain effect on the optical constant of the refined oil; moreover, the relationships between the transmittance of the refined oil and the change in temperature are obtained at 364, 378, and 394 nm; these wavelengths are selected based on a combination of characteristic spectra calculated by a genetic algorithm. The obtained relationship can effectively remove the influence of temperature changes on the transmittance spectra of refined oil to improve the accuracy of detection. [ABSTRACT FROM AUTHOR]

Densities (ρ), speeds of sound (u), and viscosities (η) of binary mixtures of N,N-dimethyl benzyl amine (DMBA) with 1,2-dichlorobenzene (1,2-DCB), 1,3-dichlorobenzene (1,3-DCB), and 1,2,4-trichlorobenzene (1,2,4-TCB) were measured at temperatures ranging from 303.15 K to 313.15 K for selected compositions. Excess molar volume (VE), excess isentropic compressibility (κsE), viscosity deviation (Δη), and excess Gibbs free energy for activation of viscous flow (ΔG*E) were subsequently determined from the experimental data. The obtained results were analysed to elucidate the nature of intermolecular interactions, specifically focusing on attractive forces, steric hindrance or hetero-association within the mixtures. The Prigogine–Flory–Patterson (PFP) theory was employed to identify the dominant type of molecular interaction. The Jouyban–Acree model was applied to calculate densities, speeds of sound, and viscosities. The accuracy of the model was evaluated using mean relative deviations (MRDs) and individual relative deviations (IRDs) between the calculated and experimental values. [ABSTRACT FROM AUTHOR]

Glibenclamide (GBN) is a commonly used oral medication for treating type-II diabetes that acts by reducing high blood sugar levels. The effectiveness of GBN depends on the quality of the product. The quality is influenced by the solubility properties of a drug. This study aimed to measure the solubility of GBN in various solvent mixtures including some glycols and alcohols. The solubility was determined using a shake-flask method at 298.2 K under atmospheric pressure. The results showed that GBN had the highest solubility in ethylene glycol monomethyl ether and alcohol mixtures compared to the other tested glycols. [ABSTRACT FROM AUTHOR]

This study examines intermolecular interactions in binary mixtures of N,N-dimethyl benzyl amine (DMBA) with short-chain alkoxy ethanols (2-methoxy ethanol (ME), 2-ethoxy ethanol (EE) and 2-butoxy ethanol (BE)). Densities (ρ), speeds of sound (u) and viscosities (η) were measured from 303.15 K to 313.15 K at atmospheric pressure for all compositions. These data were used to determine excess thermodynamic and transport properties: excess molar volume (VE), excess isentropic compressibility (κsE), viscosity deviation (Δη) and excess Gibbs free energy of activation (ΔG*E). Partial and infinite dilution molar partial properties were also calculated. Results focus on complex formation driven by chemical forces. The Jouyban–Acree model predicted these properties, with accuracy assessed using mean relative deviations (MRDs) and individual relative deviations (IRDs). FTIR spectroscopy provided additional insights into intermolecular interactions. [ABSTRACT FROM AUTHOR]

A thorough investigation into binary mixtures of propargyl alcohol and various carboxylic acids (ethanoic, propanoic and butanoic) was conducted. Measurements of density (ρ), speed of sound (u) and viscosity (η) were meticulously performed across the entire range of mole fractions at temperatures (303.15 K−313.15 K) and atmospheric pressure (0.1 MPa). These data were used to calculate key thermodynamic and transport properties, including excess molar volume, excess isentropic compressibility, deviation in viscosity and excess Gibbs free energy of activation for viscous flow. The partial molar properties and infinite dilution molar partial properties were also determined for each binary system. Trends and behaviours were interpreted within the framework of intermolecular interactions, focusing on complex formation and specific chemical forces. The PFP theory and Jouyban–Acree model were critically applied, with confidence in the findings supported by FTIR studies. [ABSTRACT FROM AUTHOR]

The viscosity ($\eta $ η) and speed of sound ($u$ u) of binary pentyl acetate (1) + isomers of butanol (2) mixtures were reported at T = 298.15 K to 318.15 K and at 0.1 MPa pressure. Using the experimental data, deviation in viscosity ($\Delta \eta $ Δη), deviation in speed of sound ($\Delta u$ Δu), and excess isentropic compressibility (${\kappa _s}^E$ κ s E ) were determined and these were fitted with the RK equation. The findings suggest that the behaviour of a mixture is affected by intermolecular interactions (dipole – dipole, H – bonding, dispersive, and cohesive force) and structural aspects of the molecule. The $\Delta \eta $ Δη and ${\kappa _s}^E$ κ s E curves were predicted well with the Singh model and ab – initio approach. At each temperature, the ${\kappa _s}^E$ κ s E values were positive for binary mixtures, whereas the $\Delta \eta $ Δη and $\Delta u$ Δu values were negative. The numeric values of $u$ u were determined through numerous correlations. This study delves into the relative importance of these relations with the experimental values of $u$ u. [ABSTRACT FROM AUTHOR]

The frequency-dependent complex permittivity spectra (CPS) of the acrylonitrile (ACRN) and 1,4-dioxane (DX) binary mixture in the range from 10 MHz to 30 GHz were measured using the time domain reflectometry (TDR) technique. Experimentally obtained CPS was fitted into the Debye equation. Dielectric relaxation behaviours depend on the temperature and concentration of binary mixtures. The obtained dielectric parameters, the Kirkwood correlation, and the Bruggeman factor have been discussed to understand the molecular association and hydrogen bonding interactions in the mixture. [ABSTRACT FROM AUTHOR]

Surface‐enhanced Raman spectroscopy (SERS) was utilized to measure low‐level fentanyl concentrations mixed in common cutting agents, cocaine, 3,4‐methylenedioxymethamphetamine (MDMA), methamphetamine, and caffeine. Mixtures were prepared with a fentanyl concentration range of 0–339 μM. Data was initially analyzed by plotting the area of a diagnostic peak (1026 cm−1) against concentration to generate a calibration model. This method was successful with fentanyl/MDMA samples (LOD 0.04 μM) but not for the other mixtures. A chemometric approach was then employed. The data was evaluated using principal component analysis (PCA), partial least squares (PLS1) regression, and linear discriminant analysis (LDA). The LDA model was used to classify samples into one of three designated concentration ranges, low = 0–0.4 mM, medium = 0.4–14 mM, or high >14 mM, with fentanyl concentrations correctly classified with greater than 85% accuracy. This model was then validated using a series of "blind" fentanyl mixtures and these unknown samples were assigned to the correct concentration range with an accuracy >95%. The PLS1 model failed to provide accurate quantitative assignments for the samples but did provide an accurate prediction for the presence or absence of fentanyl. The combination of the two models enabled accurate quantitative assignment of fentanyl in binary mixtures. This work establishes a proof of concept, indicating a larger sample size could generate a more accurate model. It demonstrates that samples, containing variable, low concentrations of fentanyl, can be accurately quantified, using SERS. [ABSTRACT FROM AUTHOR]