Types Of Phase Behavior Research Articles

Calculation of critical endpoints and phase diagrams of highly asymmetric binary systems

The computation of Global Phase Equilibrium Diagrams (GPED) for binary systems, including critical and three-phase equilibrium curves, is crucial for analyzing process conditions and assessing thermodynamic models. In the past two decades, algorithmic strategies and GPEC software have become essential tools. However, numerical problems can arise with the original algorithm for highly asymmetric systems, such as gases or water with heavy compounds or polymers, hindering the completion of GPED and related diagrams.This study presents an innovative calculation methodology to address these challenges. Our approach extends existing algorithms to achieve automatic GPED generation without user intervention, focusing on nearly pure phases. We apply our methodology to systems such as methane or water with heavy alkanes, and CO2 + silicones. The proposed algorithmic strategies effectively handle asymmetric systems, different types of phase behavior, and the estimation of extremely low concentrations in nearly pure phases along the vapor-liquid-liquid equilibrium curve.

Liquid-liquid phase of imidazolium-based ionic liquids in n-butyl acetate + n-butanol mixtures: Experimental measurements, quality testing, phase stability, thermodynamic modeling

The ester n-butyl acetate is an important chemical compound produced by esterification with n-butanol and used as solvent for pigments, vegetable oils and fats, and in the production of varnishes, coatings, waxes and resins. This work investigated the use of ionic liquids (ILs) as solvents in separation processes involving these substances. The ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]) was synthesized, while 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]) and 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) were purchased. The liquid–liquid equilibrium (LLE) was analyzed based on the experimental measurements (binodal curve, tie-lines), σ-profiles analysis (COSMOTherm), experimental data quality tests, phase stability and thermodynamic modeling with NRTL for the n-butyl acetate + n-butanol + IL ([BMIM][Cl], [EMIM][EtSO4], [EMIM][BF4]) systems at 298.15 K and 101.3 kPa. Experimental results indicated that the studied systems had the LLE phase behavior of type I. Experiments and calculations showed that [EMIM][EtSO4] and [BMIM][Cl] had the best capacities to separate the azeotrope n-butanol and n-butyl acetate. All systems showed separation factors values higher than unity. Low deviations, in the compositions of both liquid phases, indicate that the NRTL model was able to analyze the phase stability and model the phase behavior of the n-butyl acetate + n-butanol + IL systems using gamma-gamma approach.

Liquid-Liquid Phase Separation of Aqueous Ionic Liquids in Covalent Organic Frameworks for Thermal Switchable Proton Conductivity.

Covalent organic frameworks (COFs) have regular channels that can accommodate guest molecules to provide highly conductive solid electrolytes. However, designing smart, conductive COFs remains a great challenge. Herein, we report the first example of PEG-functionalized ionic liquids (ILs) anchored on the COF walls by strong hydrogen bonding to fabricate thermally responsive COFs (ILm@COF). We found that similar to the traditional IL/water mixture, the ILs undergo lower critical solution temperature (LCST)-type phase behavior within COF nanopores under high moisture levels. However, the phase separation temperature of aqueous IL decreases in COF channels due to the strong interaction between the IL and COF. Thus, the proton conductivity of ILm@COF can be reversibly switched by phase miscibility and separation in COF nanopores, and there is no obvious decrease even after 20 switching cycles. Our work provides important clues for understanding liquid-liquid phase separation in a confined nanospace and opens a new pathway to switchable proton conductivity.

Partial Miscibility and Concentration Distribution of Two-Phase Blends of Crosslinked NBR and PVC

We found that the blends of nitrile butadiene rubber (NBR) and polyvinyl chloride (PVC) exhibited lower critical solution temperature (LCST)-type phase behavior in which a single-phase blend tends to phase separate at elevated temperatures when the acrylonitrile content of NBR was 29.0%. The tan δ peaks, which originated from the glass transitions of the component polymers measured by dynamic mechanical analysis (DMA), were largely shifted and broader in the blends when the blends were melted in the two-phase region of the LCST-type phase diagram, suggesting that NBR and PVC are partially miscible in the two-phase structure. The TEM-EDS elemental mapping analysis using a dual silicon drift detector revealed that each component polymer existed in the partner polymer-rich phase, and the PVC-rich domains consisted of aggregated small PVC particles the size of several ten nanometers. The partial miscibility of the blends was explained by the lever rule for the concentration distribution in the two-phase region of the LCST-type phase diagram.

Applicability of the Generalized Stokes-Einstein Equation of Mode-Coupling Theory to Near-Critical Polyelectrolyte Complex Solutions.

We examine whether the mode-coupling theory of Kawasaki and Ferrell (KF) [Kawasaki, K. Kinetic Equations and Time Correlation Functions of Critical Fluctuations. Ann. Phys. 1970, 61 (1), 1-56; Ferrell, R. A. Decoupled-Mode Dynamical Scaling Theory of the Binary-Liquid Phase Transition. Phys. Rev. Lett. 1970, 24 (21), 1169-1172] can describe dynamic light scattering (DLS) measurements of the dynamic structure factor of near-critical polyelectrolyte complex (PC) solutions that have been previously shown to exhibit a theoretically unanticipated lower critical solution temperature type phase behavior, i.e., phase separation upon heating, and a conventional pattern of static critical properties (low angle scattering intensity and static correlation, ξs) as a function of reduced temperature. Good qualitative accord is observed between our DLS measurements and the KF theory. In particular, we observe that the collective diffusion coefficient Dc of the PC solutions obeys the generalized Stokes-Einstein equation (GSE), Dc = kBT/6πηξs, where ξs is specified from our previous measurements and where η is measured by capillary rheometry under the same thermodynamic conditions as in our previous study of these solutions, allowing for a no-free-parameter test of the GSE. We also find that even the wavevector (q)-dependent collective diffusion coefficient Dc(q), measured by varying the scattering angle in the DLS measurements over a large range, is also well-described by the mean-field version of the KF theory. We find it remarkable that the KF theory provides such a robust description of collective diffusion in these complex charged polyelectrolyte blends under near-critical conditions given that charge fluctuations and association of the polymers might be expected to lead to physical complications that would invalidate the standard model of uncharged fluid mixtures.

Influence of dispersive long-range interactions on transport and excess properties of simple mixtures

The influence of dispersive long-range interactions on liquid bulk phase transport and excess properties of six binary Lennard–Jones (LJ) mixtures was studied by molecular dynamics simulation and equation of state modelling. For the transport properties, the self-diffusion coefficients, mutual diffusion coefficients, shear viscosity, and thermal conductivity were considered. For the excess properties, the excess energy, volume, Gibbs energy, and entropy were studied. Moreover, the thermodynamic factor was studied. The two components had the same size parameter in all cases, but different dispersion energies and different cross-interaction parameters. Thereby, the six resulting mixtures show three types of phase behaviour: ideal, high- and low-boiling azeotrope. For studying the influence of the dispersive long-range interactions, the results of the full LJ potential were compared to the LJ truncated and shifted (LJTS) potential applying the corresponding states principle. The dispersive long-range interactions have a significant influence on the self-diffusion and the mutual diffusion coefficients, whereas the shear viscosity and the thermal conductivity are hardly affected. For all investigated properties, the dispersive long-range interactions have practically no influence on the composition dependency.

Phase equilibria of symmetric Lennard-Jones mixtures and a look at the transport properties near the upper critical solution temperature.

This study investigates phase equilibria and transport properties of five symmetric binary Lennard-Jones mixtures using molecular simulation and equation of state models. The mixtures are selected for their representation of different types of phase behavior and the research contributes to the development of simulation techniques, mixture theories and understanding of thermophysical mixture properties. A novel method is introduced for determining the critical end point (CEP) and critical azeotropic end point (CAEP) by molecular simulation. The van der Waals one-fluid theory is assessed for its performance in conjunction with Lennard-Jones equation of state models, while addressing different phase equilibrium types simultaneously. An empirical correlation is introduced to account for deviations between the equation of state and simulation that arise when using the same binary interaction parameter. This study also investigates the influence of the liquid-liquid critical point on thermophysical properties, which are found to exhibit no significant anomalies or singularities. System-size effects of diffusion coefficients are addressed by extrapolating simulation data to the thermodynamic limit and applying analytical finite-size corrections.

Miscibility of Poly(lactide-co-glycolide) in Supercritical fluids

In a polymer based drug delivery system, the polymer material surrounds the drug and delivers the substance to the desired target. Poly(lactide-co-glycolide) (PLGA) is the most widely used control-release system for many drugs with a short half-life, low stability, easy decomposition, and non-toxic side effects. Supercritical fluid (SCF) technology can be used to prepare or micronize drug-loaded particles without additional purification or cleaning procedures. In this work, the liquid–liquid phase transition of PLGA in several supercritical fluids, such as dimethyl ether (DME), CO2, chlorodifluoromethane (HCFC-22), and trifluoromethane (HFC-23), has been investigated. PLGA with a higher content of glycolide in the copolymer backbone shows upper critical solution temperature (UCST)-type phase behavior. Alternatively, in supercritical HCFC-22, lower critical solution temperature (LCST)-type phase behavior has been observed. The ratio of lactide to glycolide in the PLGA copolymer backbone majorly controls the phase behavior including the pressure–temperature (p-T), temperature-polymer weight fraction (T-w), pressure-density (p-ρ), and temperature-density (T-ρ) isopleths. The phase behaviors of PLGA in SCF CO2 and DME change from UCST- to LCST-type behavior with an increase in the lactide content. In contrast, PLGA in SCF HCFC-22 exhibits LCST-type phase behavior for all PLGA copolymers irrespective of the lactide content. Such phase behaviors are described well by the perturbed-chain statistical associating fluid theory (PC-SAFT) in a wide range of temperature (300–395 K) and pressure (3–310 MPa) with temperature-independent binary interaction parameters. In addition, significant differences have been observed in the solubility of PLGA in different SCFs; CO2 being the poorest solvent, and HCFC-22 being the best solvent.

Transport properties of binary Lennard-Jones mixtures: Insights from entropy scaling and conformal solution theory

The relation of transport properties and the molecular interactions in binary mixtures was studied. The self-diffusion coefficient, Maxwell–Stefan as well as Fickian mutual diffusion coefficient, shear viscosity, and thermal conductivity of liquid binary simple mixtures were therefore sampled using molecular dynamics simulations. The mixtures were described by the Lennard-Jones potential. The molecular interaction parameters were chosen such that a large variety of mixture behavior was covered. The two components had the same size parameter in all cases, but different dispersion energies. Moreover, the cross-interaction parameter used in the modified Lorentz-Berthelot combination rule was varied such that the resulting mixtures showed different types of phase behavior: ideal, high- and low-boiling azeotrope. The results are discussed using conformal solution theory as a link between the molecular interactions in the mixtures and the macroscopic properties. Moreover, the applicability of Rosenfeld’s entropy scaling is tested. Despite the important differences of the studied mixtures regarding their molecular interactions and the large pressure, temperature, and composition range considered, a practically monovariate relation of these properties with respect to the configurational entropy is observed. Yet, the quality of the approximation differs for the studied properties.

Smart Protein Refolding System Based on UCST-Type Ureido Polymers.

We have reported that ureido polymers exhibit upper critical solution temperature (UCST)-type phase behavior in solution, which is the opposite of lower critical solution temperature (LCST)-type behavior. Furthermore, UCST-type ureido polymers undergo liquid-liquid phase separation (LLPS) upon cooling rather than the liquid-solid phase transition of the typical LCST-type polymers. In this study, ureido polymers with hydrophobic groups were prepared to evaluate the effects of cooling-induced LLPS of UCST-type polymers on refolding of proteins. When protein was heated with a ureido polymer functionalized with undecyl groups, aggregation of the protein was prevented. Subsequent cooling incubation resulted in the spontaneous release of the protein from the polymer. The released protein had enzymatic activity, suggesting that the protein refolded properly. Interestingly, efficient refolding was observed when the solution of the UCST-type ureido polymer and protein was incubated at around the phase separation temperature of the polymer, implying that cooling-induced LLPS of the polymer enhanced the release of the protein. Additionally, by centrifugation at 4 °C, the refolded protein was readily separated from the ureido polymers, which precipitated upon cooling.

Experimental study on the imbibition mechanism of the Winsor type Ⅰ surfactant system with ultra-low IFT in oil-wet shale oil reservoirs by NMR

Surfactants enhanced spontaneous imbibition is an effective method to improve the oil recovery of shale reservoirs. The popular perspective believes that the wettability alteration and the capillary force are the primary mechanisms. Thus a water-wet condition and a relatively high interfacial tension (IFT) are required. However, in this work, we found that the Winsor type I surfactant solution with ultra-low IFT performed better than other relatively higher-IFT solutions with the capillary effect in oil-wet shale reservoirs. The contact angle, spontaneous imbibition recovery and phase behavior of the Winsor type I surfactant solutions were measured and compared with the solutions with relatively high IFT, including water, nonionic, and anionic surfactant solutions. The results demonstrated that anionic surfactants and Winsor type I surfactant solutions could alter the wettability to a water-wet condition, while the nonionic surfactants could only change to an intermediate-wet state. Both the anionic surfactants and Winsor type I surfactant solutions could displace the oil from micropores and mesopores. Still, the Winsor type I surfactant solutions with ultra-low IFT showed a better performance than the anionic surfactants with relatively high IFT. The interfacial micrographs of the Winsor type I surfactant solutions in contact with the oil phase manifested that the Winsor type I surfactant solutions changed the recovery patterns from two-phase flow driven by capillary force to the migration of microemulsions and emulsions driven by diffusion and gravity. The over-equilibrium Winsor type Ⅲ microemulsions and emulsions are rapidly formed near the oil-water interface. After that, the over-equilibrium Winsor type Ⅲ microemulsions are gradually diluted to Winsor type Ⅰ microemulsions and dissolved in a fresh surfactant solution. At the same time, the emulsions diffuse firstly, then coalesce and migrate out of the pore mediums driven by buoyancy. The water-wet condition and capillary force are not significant for this flow pattern, thus the Winsor type I surfactant solutions with ultra-low IFT are especially effective in recovering the oil of oil-wet micropores and mesopores. This work provides a new way of exploiting the oil in organic matter pores that can barely change to water-wet conditions.

Reentrant phase transitions in Einstein-Maxwell-scalar black holes

We consider how scalar fields affect the thermodynamic behavior of charged anti-de Sitter (AdS) black holes. We specifically investigate a class of (3+1)-dimensional exact hairy charged AdS black hole solutions to Einstein-Maxwell-scalar gravity, whose stable ground state and finite horizon area in the zero temperature limit make it of particular interest. We find that the reverse isoperimetric inequality is satisfied for this class and that there exists an intermediate range of the charge that admits reentrant phase behavior, the first example of this type of phase behavior in (3+1) dimensions in a consistent theory.

Predicting the phase equilibria of binary mixtures containing carbon dioxide + n-alkanols from a quadrupolar SAFT-VR approach

The vapor–liquid equilibria of binary mixtures containing carbon dioxide + n-alkanols is studied in the framework of the statistical associating fluid theory for potentials of variable range (SAFT-VR). The effect of the quadrupole moment of carbon dioxide on the phase equilibria is considered into the original SAFT-VR approach by incorporating an additional contribution to the Helmholtz free energy due to quadrupole–quadrupole interactions. The carbon dioxide is modeled as two spherical segments tangentially bonded with an axial quadrupolar moment. The n-alkanol molecules are represented as chains of spherical monomer segments with three associating sites to describe the hydrogen bonding interactions between the molecules. The association effects are taken into consideration by using the first-order thermodynamic perturbation theory of Wertheim. The attractive interactions between monomer segments and site-site associative interactions have been accounted for by using a square-well intermolecular potential. The pure component parameters for carbon dioxide and n-alkanols (from methanol to 1-decanol) are obtained by fitting the SAFT-VR approach to experimental saturated liquid density and vapor pressure. These optimized parameters are used to determine the vapor–liquid equilibria of the mixtures. The pressure-composition and density-composition projections predicted by SAFT-VR for the carbon dioxide + n-alkanols are in good agreement with the experimental data. A significant improvement in the description of the vapor–liquid equilibria of binary mixtures containing carbon dioxide + n-alkanols is obtained with the quadrupolar contribution compared with the results obtained from the original SAFT-VR. The optimized molecular parameters are rescaled in order to determine critical lines and the types of phase behavior. The critical lines and critical points are predicted by the original SAFT-VR approach and the quadrupolar version of the SAFT-VR in good agreement with experimental data. The inclusion of the quadrupolar interactions, present in the carbon dioxide, avoids the treatment of these interactions in an effective way via the square-well potential of variable range. The results of the present work are useful for further exploration of adsorption-extraction of n-alkanols in supercritical fluids.

Temperature-switchable deep eutectic solvents for selective separation of aromatic amino acids in water

Amino acids are vital compounds in animal and human nutrition. However, itisstillagreatchallengeto develop a cost-effective process for selective separation of amino acids. In the present study, a class of deep eutectic solvents (DESs) with short-chain alkanolamines as hydrogen bond acceptors (HBAs) and phenolic compounds as hydrogen bond donors (HBDs) have been explored for selective separation of aromatic amino acids for the first time. It is found that these DESs exhibit upper critical solution temperature (UCST)-type phase behavior in water, and their phase transition temperature is related with the pKa values of HBAs and HBDs as well as the hydrophobicity of HBDs. The UCST-type phase separation process is investigated by dynamic light scattering (DLS), FT-IR spectroscopy and temperature-variable 1H NMR in details, and the stability of the DESs in water is also examined. Interestingly, these UCST-type DESs/water systems are applicable to selective separation of aromatic amino acids. The separation factor between L-tryptophan and L-tyrosine as well as between L-tryptophan and L-phenylalanine can reach up to 476.1 and 87.9, respectively, which is about 20 and 19 times that reported in ionic liquids-based extraction solvents.

Prospective principles of catalyst utilization using supercritical fluid media

An overview of prospective principles of catalyst utilization using supercritical fluid media is presented. The processes in which these working media act as solvents and extractants, reagents and reaction media are considered. At the same time, we are talking about both heterogeneous catalysts and catalytic complexes dissolved in the water runoff of industrial enterprises. Using the LD-145 catalyst as an example, we studied the possibility of extending its service life instead of recycling, due to a change in the physical and chemical principles of its regeneration. We are talking about replacing the high-temperature process of vapor-air oxidation of catalyst-deactivating compounds with a supercritical fluid extraction process. At the same time, the extractant used is not widespread carbon dioxide, but propane/butane mixture, the use of which makes the process significantly more efficient. This is because a number of binary systems “deactivating compound – extractant” change the type of phase behavior from V-VI to I-II when changing carbon dioxide to propane/butane mixture. Thus, these systems, for example, involving naphthalene, phenol and some other substances in the supercritical fluid state fall outside the binodal of the binary system into the region of unlimited miscibility of components, which significantly increases the kinetics of the catalyst regeneration.

Tunable Lower Critical Solution Temperature of Poly(butyl acrylate) in Ionic Liquid Blends

We describe the lower critical solution temperature (LCST)-type phase behavior of poly(butyl acrylate) (PBA) dissolved in hydrophobic 1-alkyl-3-methylimidazolium bis{(trifluoromethyl) sulfonyl}amide ionic liquids (ILs). The temperature-composition phase diagrams of these PBA/ILs systems are strongly asymmetric with the critical composition shifted to low concentrations of PBA. As the molecular weight increases from 5.0×103 to 2.0×104, the critical temperature decreases by about 67 °C, and the critical composition shifts to a lower concentration. Furthermore, the LCST of PBA/ILs system increases as increasing the alkyl side chain length in the imidazolium cation. Using IL blends as solvents, the LCST of PBA can be tuned almost linearly over a wide range by varying the mixing ratio of two ionic liquids without modifying the chemical structure of the polymers.

Self-Assembly of Block Copolymers in an Ionic Liquid and Properties of Resulting Ion Gels

Ionic liquids (ILs), which are salts with low melting points, show unique properties including non-volatility and high ionic conductivity. By combining an ionic liquid (IL) with an amphiphilic ABA-type triblock copolymer, polystyrene (PSt)-b-poly(methyl methacrylate) (PMMA)-b-PSt (SMS), insoluble A blocks aggregate and form cross-linking points, whereas soluble B blocks form a gel network swollen with the IL.[1,2] As a result, a self-standing and highly ion-conductive ion gels can be obtained, and they have been applied to electrochemical devices such as polymer actuators. In these devices, the mechanical toughness and ionic conductivity are important parameters. Thus, we have investigated the correlation between microstructures formed by the block copolymer and the properties of ion gels such as ionic conductivity and mechanical property. In particular, we focused on a gyroid structure in which both insoluble and soluble segments form continuous phases, because this unique microstructure is expected to exhibit high mechanical strength and favorable ionic conductivity, simultaneously. In this study, we directly observed microstructures using AFM to investigate how microstructures affect properties of the ion gel. Herein, we used poly(ethylene oxide) (PEO), which has a lower glass transition temperature (T g) than PMMA, as a middle block (PSt-PEO-PSt, SOS). Consequently, SOS showed various microstructures including the gyroid depending on block ratio and content of IL. It was found that ionic conductivity and mechanical property strongly depended on the connectivity of microstructures. Namely, the gyroid structure showed the enhanced mechanical property and good ionic conductivity.In addition, we observed in-situ change in the microstructure for a stimuli responsive ion gel containing temperature-responsive poly(N-isopropylacrylamide) (PNIPAm) blocks: PNIPAm is known to show lower critical solution temperature (LCST)-type phase behavior in water while showing upper critical solution temperature (UCST)-type phase behavior in ILs.[3] PNIPAm-b-PEO-b-PNIPAm (NON) exhibits gel-to-sol transition in IL with increasing temperature due to the UCST-type phase transition of PNIPAm blocks. We have also reported photo-responsive gel-to-sol transition of ion gels by introducing a photo-responsive azobenzene moiety to either IL or polymer.[2] These transition phenomena have been studied in terms of a macroscopic property such as rheological property. However, little is known about their microstructure during the photo-responsive change. Thus, we observed the photo-responsive change in the microstructure using AFM and investigated how the microstructure change is synchronized with the rheological response. We found that UV irradiation induced the change in the microstructures from a microphase-separated gel to a sol with a vague structure, and it was correlated with the photo-responsive change in the mechanical property and ionic conductivity. Acknowledgements This work was financially supported by the Grant-in-Aid for Scientific Research for Basic Research S (15H05758) from Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.

Utilization of Wood Railway Sleepers Using a Supercritical Fluid Extraction Process

In this work, we propose an alternative method for the utilization of sleepers, based on the use of a supercritical fluid extraction process. The preference for the implementation of a supercritical fluid extraction process for “extractable-extractant” systems exhibiting I–II types of phase behavior is given. On the example of supercritical fluid extraction of the impregnation material of spent wood railway sleepers, the efficiency of replacing the carbon dioxide participating as an extractant with a propane/butane mixture, which provide the desired change in the type of phase behavior in relation to such components of the impregnation material as phenol, anthracene and naphthalene is shown. The phase equilibria of thermodynamic systems involving carbon dioxide and a propane/butane mixture on the one hand and coal oil components such as phenol, anthracene, and naphthalene on the other are studied. The proposed method of processing spent railway sleepers allows you to select from it up to 97 % of the mass impregnation source material.

Molecular interactions at vapor-liquid interfaces: Binary mixtures of simple fluids.

Properties of vapor-liquid equilibria and planar interfaces of binary Lennard-Jones truncated and shifted mixtures were investigated with molecular dynamics simulations, density gradient theory, and conformal solution theory at constant liquid phase composition and temperature. The results elucidate the influence of the liquid phase interactions on the interfacial properties (surface tension, surface excess, interfacial thickness, and enrichment). The studied mixtures differ in the ratios of the dispersion energies of the two components ɛ_{2}/ɛ_{1} and the binary interaction parameter ξ. By varying ξ and ɛ_{2}/ɛ_{1}, a variety of types of phase behavior is covered by this paper. The dependence of the interfacial properties on the variables ξ and ɛ_{2}/ɛ_{1} reveals regularities that can be explained by conformal solution theory of the liquid phase. It is thereby shown that the interfacial properties of the mixtures are dominated by the mean liquid phase interactions whereas the vapor phase has only a minor influence.

Influence of dispersive long-range interactions on properties of vapour–liquid equilibria and interfaces of binary Lennard-Jones mixtures

The influence of dispersive long-range interactions on properties of vapour–liquid equilibria and interfaces of six binary Lennard-Jones (LJ) mixtures was studied by molecular dynamics (MD) simulations and density gradient theory (DGT). The mixtures were investigated at a constant temperature T, at which the low-boiling component, which is the same in all mixtures, is subcritical. Two different high-boiling components were considered: one is subcritical, the other is supercritical at T. Furthermore, the unlike dispersive interaction was varied such that mixtures with three different types of phase behaviour were obtained: ideal, low-boiling azeotrope, and high-boiling azeotrope. In a first series of simulations, the full LJ potential was used to describe these mixtures. To assess the influence of the long-range interactions, these results were compared with simulations carried out with the LJ truncated and shifted (LJTS) potential applying the corresponding states principle. The dispersive long-range interactions have a significant influence on the surface tension and the interfacial thickness of the studied mixtures, whereas the relative adsorption and the enrichment are hardly affected. Furthermore, the influence of the long-range interactions on Henry's law constants and the phase envelopes of the vapour–liquid equilibrium was investigated. The long-range interactions have practically no influence on the composition dependency of the investigated mixture properties.