Equimolar Ternary Mixtures Research Articles

Dielectric characterization studies of hydrogen-bonded polar liquids in nonpolar medium using cavity perturbation technique

The dielectric characteristics of polar substances like propan-1-ol, propionaldehyde, isopropyl amine & its equimolar ternary mixtures in benzene are examined at discrete microwave frequency region using the cavity perturbation technique at 6.218 GHz (J-band), 9.880 GHz (X-band), 16.331 GHz (P-band) and 24.951 GHz (K-Band) at room temperature. The minimum energy geometry optimization is performed at 6-311G+ (d, p), 6-311G++ (d, p) basis set with DFT(B3LYP) method for both pure as well as ternary mixtures of propan-1-ol, propionaldehyde & isopropyl amine liquid systems. The dipole moment(s) of these combinations are evaluated using Higasi's approach and verified with theoretical data. The average relaxation times of the ternary solutions are calculated using the Cole-Cole plots. The mean molecular polarizability values of distinct systems of propan-1-ol, propionaldehyde, isopropyl amine, and their ternary solutions are calculated with Lippincott-δ function model. The findings are described through the molecular association between the components by hydrogen bonding.

Designing monovalent selective anion exchange membranes for the simultaneous separation of chloride and fluoride from sulfate in an equimolar ternary mixture

Selective removal of multiple counter-ions in a single mixture is highly desirable for many industrial applications but also very challenging. This study focuses on designing monovalent selective anion exchange membranes (AEMs) for the simultaneous separation of F− and Cl− from SO42− using electrodialysis (ED). A series of brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) polymers with adjusted bromination degrees at benzyl and aryl positions were synthesized, and quaternized with different tertiary amines of varying chain lengths to produce optimized AEMs. Differences in bromination degrees and the chain lengths of the tertiary amines alter the microstructure of AEMs, which influences the anion transport through the developed membranes. Selected AEMs were modified via layer-by-layer (LbL) deposition of poly (sodium 4-styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) polyelectrolytes to enhance their monovalent selectivity. ED tests were carried out with an equimolar ternary mixture. When 5 layers of deposition were applied, the achieved Cl−/ SO42− and F−/ SO42− selectivities were 11.7 ± 0.2 and 8.3 ± 0.3, respectively, showing significant improvement compared to a commercial monovalent selective ASVN membrane. Experimental results confirm that simultaneously optimizing membrane microstructure and surface can be an effective strategy for the separation of similar counter-ions in an ED process.

Mutual inhibition effect of sulfur compounds in the hydrodesulfurization of thiophene, 2-ethylthiophene and benzothiophene ternary mixture

The hydrodesulphurization of a model component and equimolar ternary mixture of thiophene, 2-ethylthiophene and benzothiophene over sulphided CoMo/γ-Al2O3 and CoMo/γ-Al2O3-Nb2O5 catalysts were investigated in a fixed bed flow reactor. The catalysts were prepared by incipient wetness impregnation method and characterized by textural characteristics, total acidity and chemical species present on the catalysts surface. The characterization results showed that both CoMo/γ-Al2O3-Nb2O5 and sulphided CoMo/γ-Al2O3 catalysts exhibit a mesoporous structure with cylindrical pores open at both ends, evidenced by the IV type adsorption–desorption isotherm with a H1 hysteresis loop and have an average pore diameter between 3 and 4 nm. The chemical species present on the catalysts surface evaluated by XPS indicated that Co2+ and Mo4+ species are present in the sulfide form on both catalysts surfaces. In addition, there are also found oxidic species arising from incomplete reduction and sulphidation. The presence of niobium oxide in the catalytic support had a positive effect in leading to higher specific surface area (170 m2/g) and total acidity (0.421 meq/g) compared with CoMo/γ-Al2O3 catalyst (140 m2/g and 0.283 meq/g) respectively. The evaluation results from the hydrodesulfurization showed that CoMo/γ-Al2O3-Nb2O5 catalyst had a higher activity in hydrodesulphurization process of thiophene, 2-ethylthiophene and benzothiophene. The CoMo/γ-Al2O3-Nb2O5 catalyst eliminated sulfur from the single component feed (corresponding to 2380 ppm S) and reduced below 10 ppm, for the feed consisting in the equimolar ternary mixture of thiophene, 2-ethylthiophene and benzothiophene (2380 ppm S). The reactivity of thiophen compounds was reduced due to competitive adsorption. It was observed that benzothiophene inhibits the transformation of thiophene and 2-ethylthiophene. A mutual inhibition effect between sulfur compounds was also observed when thiophene, 2-ethylthiophene and benzothiophene were combined and tested over the CoMo/γ-Al2O3 catalyst. The inhibition effect had a lower intensity by introducing Nb2O5 in the catalyst support.

Alternative purification protocols of mixed pyridines in the presence of trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine

In this communication, we reveal that the host compound trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine (1,4-DAX) possesses the ability to purify 2-methylpyridine (2MP)/pyridine (PYR) and 3-methylpyridine (3MP)/PYR binary mixtures by enclathrating PYR almost exclusively, even when such mixtures contained as little as approximately 30% PYR. For example, when these solutions were prepared with equimolar quantities of the two guests, complexes contained as much as 92.4 and 96.4% PYR, respectively. Furthermore, 1,4-DAX was capable of forming a mixed complex with as high as 87.8% PYR from an equimolar ternary mixture containing 2MP, 3MP and PYR through host‒guest complexation. This work complements that of trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine (1,2-DAX) and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine (1,2-DAT), disclosed in a previous submission, where 4-methylpyridine (4MP) and 2MP, correspondingly, were the preferred guest solvents. Interestingly, trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,4-diamine (1,4-DAT) showed no inclusion tendencies under such conditions. Successfully-formed inclusion complexes were subjected to crystal X-ray diffraction analyses in order to understand the preference of 1,4-DAX for 4MP and PYR. Thermal analyses of these complexes were, however, less informative.

Imidazolium and pyridinium-based ionic liquids for the cyclohexane/cyclohexene separation by liquid-liquid extraction

The separation of olefins/paraffins is a challenge for the petrochemical industry due to the close boiling points of these hydrocarbons. In this work we have studied the feasibility of different imidazolium and pyridinium-based ionic liquids (ILs) as alternative solvents in the cyclohexane/cyclohexene separation. Five ILs have been studied, namely 1-butyl-4-methylpyridinium tricyanomethanide ([4bmpy][TCM]), bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate ([emim]2[Co(SCN)4]), bis(1-butyl-3-methylimidazolium) tetrathiocyanatocobaltate ([bmim]2[Co(SCN)4]), 1-ethyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][Tf2N]), and 1-butyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4bmpy][Tf2N]). Experimental liquid-liquid equilibrium (LLE) data were obtained for the equimolar ternary mixtures {cyclohexane (1) + cyclohexene (2) + IL (3)} at T = (298.2, 313.2 and 328.2) K and atmospheric pressure in order to study the effect of the temperature on the extractive properties. Afterwards, LLE data for every ternary system was determined at the best temperature and for the whole cyclohexane/cyclohexene composition range. These ILs have shown promising results in terms of distribution ratio and selectivity, showing the [4bmpy][TCM] IL the best extractive properties at 298.2 K and atmospheric pressure. The Non-Random Two Liquids (NRTL) model was used to successfully correlate the experimental LLE data.

Separation of cobalt, neodymium and dysprosium using amorphous zirconium phosphate

The purpose of this study was to investigate the separation of Co, Nd and Dy from a ternary Co-Nd-Dy solution using amorphous zirconium phosphate (am-ZrP). Am-ZrP was synthesized by a precipitation method at room temperature and subsequently characterized by Fourier transform-infrared spectrometry, thermogravimetry, scanning electron microscopy, X-ray diffraction, solid-state 31P magic angle spinning nuclear magnetic resonance spectrometry and sodium hydroxide titration (with and without background salt). The ion exchange kinetics of am-ZrP that were determined in ternary 1mM equimolar solutions at equilibrium pH2.5. The effect of pH on the adsorption was studied in ternary 1mM equimolar solutions and the uptakes of the metals increased with increasing pH until approximately pH3.5. The adsorption isotherms of Co, Nd and Dy were tested in a series of ternary equimolar solution, the total uptake amounted to 4.13meq/g at pH ~3.0. The preference of am-ZrP for these metals occurred in decreasing order Dy>Nd≫Co. The separation of Co, Nd and Dy from their 1mM equimolar ternary mixture was investigated on an am-ZrP column. Effects of loading (7.8%, 62% and 100%) on the separation were compared by measuring the corresponding HNO3 elution fractions. It was found that with a lower metal loading of 7.8%, three clear elution bands were obtained. Am-ZrP exhibited selective separation properties towards the ternary Co-Nd-Dy system, which contribute to the future scale-up studies for the recycling of NdFeB magnets.

VOC ternary mixture effect on ppb level photocatalytic oxidation: Removal kinetic, reaction intermediates and mineralization

This work addresses photocatalytic oxidation for indoor air purification and more especially the key and realistic issue of VOC mixture treatment. The VOC mixture effect needs to be investigated since indoor air contains several tens of VOCs which may impact photocatalytic oxidation performances. In order to be closer to realistic conditions, concentrations in the ppb range were used and toluene, decane and trichloroethylene (TCE) were treated first as single compounds, then as an equimolar ternary mixture under the same experimental conditions. In a 120L batch reactor, VOC removal kinetics, reaction intermediates and CO2 mineralization are addressed using dedicated analytical devices compliant with typical ppb level monitoring. Regarding removal kinetics, the mixture effect affects the three VOCs. Regarding toluene and decane removal kinetic, the mixture effect is evidenced as mostly equivalent to a concentration effect, however TCE kinetic is further impacted. From the reaction intermediate point of view, the accurate monitoring of transiently produced intermediates evidences for the first time cross-reactivity between reaction intermediates originating from different primary VOCs. This phenomenon leading to novel reaction intermediate is mostly induced by chlorinated species produced by TCE degradation but remains moderate. An increase in VOC initial concentration to upper ppb levels emphasized a sequential degradation of primary VOC which may be related to competitive adsorption even on such a low concentration range. Finally, even if the mixture effect delays the removal of the primary VOCs, mineralization is slightly modified and, unlike formerly reported experiments on ppm range, final mineralization rates are equivalent under single or mixture condition at ppb levels. This work highlights the fact that photocatalytic treatment of VOC mixtures cannot be directly extrapolated from single VOC behaviour even at ppb level.

Effect of humic monomers on the adsorption of sulfamethoxazole sulfonamide antibiotic into a high silica zeolite Y: An interdisciplinary study

The adsorption efficiency of a high silica zeolite Y towards sulfamethoxazole, a sulfonamide antibiotic, was evaluated in the presence of two humic monomers, vanillin and caffeic acid, representative of phenolic compounds usually occurring in water bodies, owing their dimension comparable to those of the zeolite microporosity. In the entire range of investigated pH (5–8), adsorption of vanillin, as a single component, was reversible whereas it was irreversible for sulfamethoxazole. In equimolar ternary mixtures, vanillin coadsorbed with sulfamethoxazole, conversely to what observed for caffeic acid, accordingly to their adsorption kinetics and pKa values. Lower and higher adsorptions were observed for sulfamethoxazole and vanillin, respectively, than what it was observed as single components, clearly revealing guest-guest interactions. An adduct formed through H-bonding between the carbonyl oxygen of vanillin and the heterocycle NH of sulfamethoxazole in amide form was observed in the zeolite pore by combined FTIR and Rietveld analysis, in agreement with Density Functional Theory calculations of the adduct stabilization energies. The formation of similar adducts, able to stabilize other naturally occurring phenolic compounds in the microporosities of hydrophobic sorbents, was proposed.

Interaction of the Alzheimer Aβ(25–35) peptide segment with model membranes

Alzheimer’s disease is characterized by the presence of amyloid plaques in the brain. The main components of these plaques are the Aβ(1–40) and Aβ(1–42) peptides but the Aβ(25–35) sequence is the most frequently studied fragment because it represents a biologically active region of the longer Aβ peptides. In the present work, the interactions of Aβ(25–35) peptide with model membranes were investigated, taking into consideration the aggregation state of the peptide. Monolayers and liposomes were taken as model membranes with two lipid compositions: the equimolar ternary mixture of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), sphingomyelin (SM), and cholesterol (Chol) and the equimolar POPC/SM binary mixture. The interaction of Aβ(25–35) with the monolayers, investigated at low concentrations (0.25–4μM), suggested a three step mechanism: adsorption—monomers or dimers adsorb at the polar region of the lipid monolayer; nucleation—adsorbed peptides act as nucleation sites for higher aggregates; and penetration—these aggregates insert in the hydrophobic region of the monolayer. Chol slightly enhances the peptide–lipid monolayer interaction. The large aggregates nucleated in the bulk solution evidenced a weak interaction with monolayers. The interaction of Aβ(25–35) with liposomes, followed by a Quartz Crystal Microbalance with Dissipation (QCM-D) in a large range of peptide concentrations (10–80μM), was very small, independently of the peptide concentration.

Effect of glycyrrhetinic acid on lipid raft model at the air/water interface

To investigate an interfacial behavior of the aglycon of glycyrrhizin (GC), glycyrrhetinic acid (GA), with a lipid raft model consisting of equimolar ternary mixtures of N-palmitoyl sphingomyelin (PSM), dioleoylphosphatidylcholine (DOPC), and cholesterol (CHOL), Langmuir monolayer techniques were systematically conducted. Surface pressure (π)–molecular area (A) and surface potential (ΔV)–A isotherms showed that the adsorbed GA at the air/water interface was desorbed into the bulk upon compression of the lipid monolayer. In situ morphological analysis by Brewster angle microscopy and fluorescence microscopy revealed that the raft domains became smaller as the concentrations of GA in the subphase (CGA) increased, suggesting that GA promotes the formation of fluid networks related to various cellular processes via lipid rafts. In addition, ex situ morphological analysis by atomic force microscopy revealed that GA interacts with lipid raft by lying down at the surface. Interestingly, the distinctive striped regions were formed at CGA=5.0μM. This phenomenon was observed to be induced by the interaction of CHOL with adsorbed GA and is involved in the membrane-disrupting activity of saponin and its aglycon. A quantitative comparison of GA with GC (Sakamoto et al., 2013) revealed that GA interacts more strongly with the raft model than GC in the monolayer state. Various biological activities of GA are known to be stronger than those of GC. This fact allows us to hypothesize that differences in the interactions of GA/GC with the model monolayer correlate to their degree of exertion for numerous activities.

Interaction Forces between Ternary Lipid Bilayers Containing Cholesterol

Interaction force-distance profiles between substrate-supported membranes composed of equimolar ternary mixtures of unsaturated phosphotidylcholine (PC) lipid, saturated PC lipid, and cholesterol were determined using the surface force apparatus. Both double and single unsaturated PC lipids were studied. In all cases, the membranes were slightly negatively charged, resulting in a weak, long-range electrostatic repulsion. Corroborative atomic force microscopy, zeta potential, and fluorescence microscopy measurements were used to establish that a small level of charged lipid impurities (∼1/400 lipid molecules) were responsible for the repulsive electrostatic interaction between the membranes. At contact, the membranes were adhesive. The magnitude of the adhesion was greater than the van der Waals interaction between pure PC membranes without cholesterol. The enhanced adhesion was primarily attributed to hydrophobic attraction due to the presence of nanoscopic membrane defects which exposed the underlying membrane leaflet. The interaction force-distance profiles also demonstrated that the nanoscopic defects enabled membrane restructuring in the contact region.

Distribution of macular xanthophylls between domains in a model of photoreceptor outer segment membranes

A model of photoreceptor outer segment (POS) membranes has been proposed, consisting of an equimolar ternary mixture of 1-palmitoyl-2-docosahexaenoylphosphatidylcholine/distearoylphosphatidylcholine/cholesterol. It was shown that, as in membranes made from the raft-forming mixture, in the model of POS membranes, two domains are formed: the raft domain (detergent resistant membranes, DRM), and the bulk domain (detergent soluble membranes, DSM). Saturation-recovery EPR discrimination by oxygen transport method also demonstrated the presence of two domains in this model system in situ at a wide range of temperatures (10–55°C), showing additionally that neither lutein nor zeaxanthin at 1 mol% affect the formation of these domains. These membrane domains have been separated using cold Triton X-100 extraction from a model of POS membranes containing 1 mol% of either lutein or zeaxanthin. The results indicated that the macular xanthophylls lutein and zeaxanthin are substantially excluded from DRM and remain concentrated in DSM, a domain enriched in highly unsaturated docosahexaenoyl acid which is abundant in retina membranes. The concentration of xanthophylls in DRM and DSM calculated as the mol ratio of either xanthophyll to total lipid (phospholipid + cholesterol) was 0.0028 and 0.0391, respectively. Thus, xanthophylls are about 14 times more concentrated in DSM than in DRM. No significant difference in the distribution of lutein and zeaxanthin was found. The obtained results suggest that in POS membranes macular xanthophylls should also be concentrated in domains enriched in polyunsaturated chains.

Accumulation of macular xanthophylls in unsaturated membrane domains

The distribution of macular xanthophylls, lutein and zeaxanthin, between domains formed in membranes made from an equimolar ternary mixture of dioleoylphosphatidylcholine/sphingomyelin/cholesterol, called a raft-forming mixture, was investigated. In these membranes, two domains are formed: the raft domain enriched in saturated lipids and cholesterol (detergent-resistant membranes, DRM), and the bulk domain enriched in unsaturated lipids (detergent-soluble membranes, DSM). These membrane domains have been separated using cold Triton X-100 extraction from membranes containing 1 mol% of either lutein or zeaxanthin. The results indicated that xanthophylls are substantially excluded from DRM and remain concentrated in DSM. Concentrations of xanthophylls in DRM and DSM calculated as the mole ratio of either xanthophyll to phospholipid were 0.005 and 0.03, respectively, and calculated as the mole ratio of either xanthophyll to total lipid (phospholipid + cholesterol) were 0.003 and 0.025, respectively. Thus, xanthophylls are over eight times more concentrated in DSM than in DRM. No significant difference in the distribution of lutein and zeaxanthin was found. It was also demonstrated using saturation-recovery EPR that at 1 mol%, neither lutein nor zeaxanthin affect the formation of membrane domains. The location of xanthophylls in domains formed from unsaturated lipids is ideal if they are to act as a lipid antioxidant, which is the most accepted mechanism through which lutein and zeaxanthin protect the retina from age-related macular diseases.

Investigation of the mass dependence of self-diffusion coefficients by molecular dynamics calculations: binary and ternary isotopic mixtures of atoms

Extensive molecular dynamics calculations have been used to study for the first time systematically the dependence of the self-diffusion coefficients Di (i = 1, 2, 3) in binary and ternary atomic isotopic mixtures on the particle mass ratios m*2 = m 2/m 1 and m*3 = m 3/m 1 at different reduced temperatures T* and reduced particle number densities n*, using a Lennard-Jones 12-6 potential and a hard-soft-spheres potential. In addition, the dependence of Di values of binary mixtures on the mole fraction x 1 = 1—x 2 was also investigated for some thermodynamic states. The calculated values of Di can be represented quantitatively by exponential estimates of the form Di = D* i (m*2)ex i in the case of binary mixtures and Di = D 0 i (m*2)ex i (m 3)ext i in the case of ternary mixtures. D 0 i are the self-diffusion coefficients in reference mixtures of mass ratios m*2 = m*3 = 1. The dependence of the exponents ex i (m*2, T*, n*, x 1) of binary mixtures on m*2, T*, n*, and x 1 and the dependence of the exponents ext i (m*2, m*3, n*) of equimolar ternary mixtures at T* = 1.8 on the exponents ex i of the constituent binary mixtures and on m*2, m*3, and n* are discussed.

Predicting the virial coefficients and thermodynamic properties of a multicomponent mixture with application to the ternary mixture of CH2F2+CF3CHF2+CF3CH2F

A model for estimating second and third virial coefficients, which has been used successfully to represent the behavior of pure gases and binary mixtures, was applied to a ternary mixture. An estimate for the ternary third virial coefficient.C 123, was added to the model. Three experimentally determined binary interaction parameters were also used. The model has been applied to the ternary mixture CH2F2+CF3CHF2+CF3CH2F (R32+R125+R134a). The results are useful for calculating gas-phase densities, thermodynamic properties, and fugacities for phase equilibrium calculations. The use of such models leads to a considerable economy of effort in the case of multicomponent mixtures. Examples of the thermodynamic properties are given for the equimolar ternary mixture in the range from the dew-point temperature to 400 K at pressures of 0.5, 1, and 2 MPa. Calculated densities and speeds of sound are compared with new experimental values for a near-equimolar composition.

Excess Thermodynamic Properties of Ternary Fluid Mixtures from Molecular Dynamics Simulation and Van Der Waals One-Fluid Theory

Abstract In this paper, we report isothermal–isobaric molecular dynamics simulation results for total and excess thermodynamic properties of three selected nonideal ternary fluid mixtures, in which particles interact via a Lennard-Jones pair potential. In these mixtures, size parameters of the components are kept to be the same, but energy parameters of the components differ significantly. Simulation results are reported for mixture density, internal energy, excess Gibbs free energy, excess volume and excess enthalpy of equimolar ternary mixtures as a function of temperature and pressure. The excess Gibbs free energy is obtained directly using the coupling parameter charging approach, which avoids the cancellation or magnification of errors in the simulation. These simulation results are used to check the accuracy of a form of the van der Waals one–fluid theory, which uses an accurate equation of state for the pure fluids. Van der Waals one–fluid theory is successful in predicting total and excess properties of these nonideal mixtures within simulation uncertainties.

BHS theory and computer simulations of linear heteronuclear triatomic hard-sphere molecules

As an extension to a recent study of model diatomic molecules, an equation of state is determined for linear heteronuclear triatomics formed from three tangent hard spheres with diameters σ1, σ2 and σ3. Spheres 1 and 3 are positioned at each end with sphere 2 in the centre so that the 1–2 and 2–3 bond lengths are l 12 = (σ1 + σ2)/2 and l 23 = (σ2 + σ3)/2. The bonded hard-sphere (BHS) approach provides a route to the thermodynamic properties of the triatomic fluid. An equation of state is obtained from the corresponding expression for an equimolar ternary mixture of different-sized hard spheres with bonding sites. In the limit of complete bonding, the heteronuclear triatomic molecules are formed. The cases investigated are the homonuclear system with σ1 = σ2 = σ3, the symmetrical heteronuclear systems with σ1 = σ3 = σ2/4, σ1 = σ3 = 3σ2/5 and σ1 = σ3 = 4σ2, and the asymmetrical heteronuclear systems with σ1 = σ2 = 2σ3 and σ1 = 2σ2 = 4σ3. Isothermal-isobaric Monte Carlo (MC-NPT) simulations are performed for...

Short- and long-range Ca 2+-induced lateral phase separations in ternary mixtures of phosphatidic acid, phosphatidylcholine and phosphatidylethanolamine

Ca 2+-induced lateral phase separation in an equimolar ternary mixture of dipalmitoylphosphatidic acid (DPPA), dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylethanolamine (DMPE) was investigated by high-sensitivity differential scanning calorimetry. The thermogram showed a merged phase transition of these components in the absence of calcium ions, and the addition of calcium ions induced a change in the thermogram of the ternary mixture in a biphasic fashion. Different features were observed below and above a Ca 2+/DPPA molar ratio of 1. When the ratio was below 1, the transition peak shifted to a higher temperature. Within a range above 1, a major transition peak appeared at a temperature similar to the transition temperature of a binary mixture of DPPC and DMPE. The same tendency was observed in the ternary mixture in which DMPE was replaced with dilauroylphosphatidylethanolamine (DLPE) or dipalmitoylphosphatidylethanolamine (DPPE). The features of these thermograms below and above a Ca 2+/DPPA ratio of 1 could be attributed to Ca 2+-induced lateral phase separations of DPPA molecules in short-range and long-range phase separations, respectively. In order to confirm the short-range phase separation, the Ca 2+ effect on an equimolar ternary mixture of DPPA, DPPC and DMPE was examined using a spin-spin exchange interaction of stearate methyl ester spin probes. The results indicate that the long-range phase separation of phosphatidic acid induced by calcium ions is suppressed in ternary mixtures at low concentrations of Ca 2+.

Joule‐Thomson effects for mixtures of helium‐nitrogen‐methane and hydrogen‐nitrogen‐methane

AbstractExperimental isenthalps and corresponding Joule‐Thomson coefficients are reported for nitrogen and equimolar ternary mixtures of helium‐nitrogen‐methane and hydrogen‐nitrogen‐methane. The estimated precision of the Joule‐Thomson coefficients was within 1.5% of recent literature values.These Joule‐Thomson coefficients are compared with predictions from the virial equation and Beattie‐Bridgman, Benedict‐Webb‐Rubin, and Redlich‐Kwong equations of state. The predicted Joule‐Thomson coefficients are as accurate as predictions for the pure species. Standard mixing rules and methods of combining equations of state constants are satisfactory at higher temperatures. At low temperatures the predictions from the equations of state are poor.