Propylene Glycol Methyl Ether Research Articles

2-Methoxypropan-1-ol. Documentation of proposed values of occupational exposure limits (OELs)

2-Methoxypropan-1-ol is a by-product of a propylene glycol methyl ether (PGME) manufacturing process, in which it is an impurity at concentrations up to 5%. 2-Methoxypropan-1-ol as a PGME impurity can occur in industry in paints solvents, varnishes, dyes, inks, adhesion agents, ingredients in cleaning formulations and chemical synthesis intermediates. It may also occur as an impurity in cosmetics, although its use in these products is prohibited. At occupational exposure, 2-methoxypropan-1-ol may be absorbed through inhalation and skin. There are no data on the number of people exposed to this compound in Poland and no data on its toxic effects in humans. There is only one study that showed a statistically significant increase in the occurrence of birth defects in children of mothers exposed to 2-methoxypropan-1-ol. The proposed MAC value for 2-methoxypropan-1-ol (20 mg/m3) is based on the systemic toxicity demonstrated in a study on pregnant rabbits (NOAEC value of 1335 mg/m3). Due to its irritant effects, STEL value of 40 mg/m3 and “I” notation are also proposed. There is no basis for establishing a BEI value. Since dermal exposure may contribute significantly to the absorption of 2-methoxypropan-1-ol by workers, a "skin" notation is also required.

The effect of washing process on the cracking of ZrO2 microspheres by internal gelation

AbstractZrO2 microspheres are widely used as a simulant of UO2 in the development of nuclear fuel. However, the cracking of ZrO2 microspheres prepared by internal gelation is still a challenge during drying and sintering processes. To address this issue, we designed and optimized the washing process for obtaining crack‐free ZrO2 microspheres. Through thermogravimetric, infrared, Raman, BET, and SEM analysis, it is shown that the cracking of the microspheres is mainly related to the pores in microspheres. The washing solvent with low surface tension is used to reduce the effect of capillary force on pore shrinkage. Therefore, the optimal washing process was designed as trichloroethylene (TCE)—0.5 M NH3.H2O—Propylene glycol methyl ether (PM) and gel microspheres with a high specific surface area of 315.3 m2/g and pore volume of 0.4125 cm3/g were obtained. The characterizations also further showed that when the microspheres were dried and sintered, the water vapor and the decomposition gas of organic matter were completely released from the pores in the microspheres. Our new washing process could be directly extended for preparing crack‐free ceramic microspheres by internal gelation.

Fluorescent nitrogen-doped carbon nanodots synthesized through a hydrothermal method with different isomers

In this work, we have developed a novel fabrication technique for preparing N-functionalized carbon nanodots (CNDs) through one-pot hydrothermal route using various isomers, exhibiting highly intense fluorescence under blue light illumination. Three types of isomers, o-, m-, and p-phenylenediamine (PD), serving as the carbon and nitrogen sources were employed where the N/C atomic ratio in the CNDs structure was precisely tuned within the range of 20.2–25.7 at.% via tailoring the isomer precursors. The application of the m-PD precursor resulted in implanting the “lattice N” functionalities while the o-PD precursor enabled the formation of N-oxide groups. The CND suspensions in highly-polarity solvents (e.g., water and ethanol) emit intense fluorescence with ultrahigh quantum yield (QY: 85‒99%), whereas the fluorescence from the CND suspensions in propylene glycol methyl ether acetate is significantly quenched. The ultrahigh QY is majorly due to an intense radiative emission mechanism induced by the substitutional N atoms (via high electron-withdrawing) and N- and O-rich edge groups as the major contributors for boosting the affinity to high-polar solvents. Given the widespread applications of quantum dots as high-performance nanomaterials, this study paves the way for engineering N-functionalized CNDs to be used in optical, sensing, energy storage/conversion, and biological devices.

Effect of Solvent on Fluorescence Emission from Polyethylene Glycol-Coated Graphene Quantum Dots under Blue Light Illumination.

To explore aggregate-induced emission (AIE) properties, this study adopts a one-pot hydrothermal route for synthesizing polyethylene glycol (PEG)-coated graphene quantum dot (GQD) clusters, enabling the emission of highly intense photoluminescence under blue light illumination. The hydrothermal synthesis was performed at 300 °C using o-phenylenediamine as the nitrogen and carbon sources in the presence of PEG. Three different solvents, propylene glycol methyl ether acetate (PGMEA), ethanol, and water, were used for dispersing the PEG-coated GQDs, where extremely high fluorescent emission was achieved at 530–550 nm. It was shown that the quantum yield (QY) of PEG-coated GQD suspensions is strongly dependent on the solvent type. The pristine GQD suspension tends to be quenched (i.e., QY: ~1%) when dispersed in PGMEA (aggregation-caused quenching). However, coating GQD nanoparticles with polyethylene glycol results in substantial enhancement of the quantum yield. When investigating the photoluminescence emission from PEG-coated GQD clusters, the surface tension of the solvents was within the range of from 26.9 to 46.0 mN/m. This critical index can be tuned for assessing the transition point needed to activate the AIE mechanism which ultimately boosts the fluorescence intensity. The one-pot hydrothermal route established in this study can be adopted to engineer PEG-coated GQD clusters with solid-state PL emission capabilities, which are needed for next-generation optical, bio-sensing, and energy storage/conversion devices.

Study of Dried and Calcinated Ceria Stabilized Zirconia Microspheres Morphology by Small-Angle X-Ray Scattering and Optical Microscopy

The knowledge of how to avoid crack at high temperature is crucial in fuel fabrication for Experimental Power Reactor or Reaktor Daya Eksperimental (RDE). This knowledge should be established and well-mastered by BATAN. RDE uses uranium dioxide as its nuclear fuel. However, uranium utilization for research purposes is heavily restricted. Therefore, the fabrication of ceria-stabilized zirconia (CSZ) microspheres as nuclear fuel surrogate was studied. In this work, the CSZ was prepared by external gelation with two different washing solutions, i.e. isopropyl alcohol (IPA) and propylene glycol methyl ether (PGME). The morphology in nano- and micro-scale of each CSZ microspheres from both variations was evaluated by small-angle x-ray scattering (SAXS) and optical microscopy. The morphology of the CSZ microsphere after drying at 80 °C and calcination at 200 °C were observed to understand the structural change in those steps and to see the potential crack based on its morphology. There are two parameters that can prevent microspheres from cracking at high temperatures for the next process, i.e., porosity and gel texture. It was observed that IPA solution has a benefit as a washing solution as it can trigger more porosities in the microspheres, but less in gel texture.

Synthesis of metallic nanoparticles for heterogeneous catalysis: Application to the Direct Borohydride Fuel Cell

Until now, the fabrication of electrocatalysts to guarantee long life of fuel cells and low consumption of noble metals remains a major challenge. The electrocatalysts based on metals or metal oxides which are used today are limited by the complexity of their synthesis processes and require several steps before depositing the catalysts on the substrate. Herein is described a chemical synthesis process that consists of a single-step synthesis and direct deposition of catalysts nanoparticles such as gold (Au), palladium (Pd) and platinum (Pt) in the thickness of a carbon-fibers-based porous transport layer (PTL). The synthesis process essentially consists of dissolving in the same PGMEA (Propylene glycol methyl ether acetate) solvent a metal precursor (HAuCl4 or PdNO2 or PtCl4) and a homopolymer PMMA (Polymethylmetacrylate), then the metal solution is deposited on the surface of the PTL after cleaning. Special emphasis is made on Pt-based materials. The obtained PTL-supported nanoparticles were firstly characterized by scanning electron microscopy (SEM) to evaluate their morphology, and then X-Ray diffraction (XRD) to observe the crystal phases. To validate the methodology, Pt-coated PTL materials have been used as anode for the borohydride oxidation reaction (BOR) in a direct borohydride fuel cell (DBFC) and compared to a state-of-the-art nickel electrode. There is an optimum loading of platinum (below 0.16 mg Pt / cm2) which constitutes the best compromise between power density and faradic efficiency for the borohydride oxidation reaction (BOR). Thanks to this low Pt loading, hydrogen evolved during the anodic reaction is completely valorized. These electrodes combine the advantages of high-performance with a very low metal loading, hence lowering materials’cost.

Improved catalytic oxidation of propylene glycol methyl ether over Sm-Mn and Sm-Co perovskite-based catalysts prepared by the recycling of spent ternary lithium-ion battery.

The spent ternary lithium-ion batteries were utilized as the precursors to prepare Sm-Mn and Sm-Co perovskite oxides (SmMnO3-spent ternary lithium-ion battery [STLIB] and SmCoO3-STLIB) for the first time. Their catalytic activities were evaluated by catalytic oxidation of propylene glycol methyl ether. Compared with that of the catalysts synthesized by analytical reagents, the catalytic activities of SmMnO3-STLIB and SmCoO3-STLIB had been significantly enhanced. The analysis of X-ray photoelectron spectroscopy (XPS) showed that the molar ratios of Mn4+/Mn3+ and Oads/Olatt of SmMnO3-STLIB were higher than that of pure SmMnO3 and the Co3+/Co2+ ratios of SmCoO3-STLIB was much larger than that of pure SmCoO3. The hydrogen temperature-programmed reduction (H2-TPR) and N2 adsorption-desorption tests determined that the reducibilities and specific surface areas of SmMnO3-STLIB and SmCoO3-STLIB were also superior to pure catalysts. Ultimately, the by-products of the catalytic oxidation of propylene glycol methyl ether over SmMnO3-STLIB were also detected by gas chromatography-mass spectrometry (GC-MS). This work will provide a demonstration for the resource utilization of spent lithium ions batteries and the analysis of the increased activity obtained by using spent lithium ions batteries as the precursors to prepare catalysts.

Copolymerization behavior of diallyldimethylammonium chloride‐nonionic macromonomer in water‐ether mixture solution and flotation performance of the copolymer for treating oily wastewater

AbstractCopolymerization of cationic monomer and nonionic macromonomer in water‐ether mixture solution is useful for preparing the functional polymer. Copolymer of diallyldimethylammonium chloride (DMDAAC) and a nonionic block polyether macromonomer (PEP‐65) has been found that has very well reverse demulsification performance, but the polymerization phenomenon cannot be described by any reported polymerization method. In this paper, the copolymerization behavior including polymer mechanism, polymerization kinetics, and reactivity rate of DMDAAC and PEP‐65 in the mixture solution of water and propylene glycol methyl ether (PGME) was studied for explaining the special copolymerization phenomenon and its flotation performance for treating oily wastewater was also investigated. The results showed that DMDAAC‐PEP‐65 copolymerization in water‐PGME mixture solution has four stages and has both characteristics of emulsion polymerization and dispersion polymerization. In addition, the copolymer also has excellent flotation performance.

Highly fluorescent green and red emissions from boron-doped graphene quantum dots under blue light illumination

Highly fluorescent boron-doped graphene quantum dots (B-doped GQDs, average particle size of ∼4 nm) are synthesized via one-pot solvothermal route in the presence of 1,3,6-trinitropyrene (TNP) and boric acid. The chemical ratio of the boric acid to TNP precursor is identified as a crucial factor in modulating the B-dopant concentration within the GQD lattices. The GQD suspensions maintain uniform dispersion over extended operation thanks to the NO2 groups formed in the GQD edge sites promoting high dispersivity in polar and nonpolar solvents. The B-doped GQD suspensions are homogeneously stored in n-hexane and propylene glycol methyl ether acetate, enabling highly fluorescent green and red emission, respectively. Under the blue-light illumination, the green emission takes place at ca. 541 nm with a narrow full width at half maximum (FWHM) of 31.7 nm, whereas the red emission centers at ca. 617 nm with a FWHM of 42.5 nm. Through adjusting the concentration of B-dopant, the quantum yield of green and red fluorescence reached as high as 99.8 and 17.1%, respectively. Accordingly, the novel solvothermal synthesis route developed in this work provides the essential framework for engineering B-doped GQDs with tunable optical properties for high-performance biosensors and biomedical devices.

Homo- and co-polymerisation of di(propylene glycol) methyl ether methacrylate – a new monomer

A new methacrylate monomer with two propylene glycol groups on the side chain, di(propylene glycol) methyl ether methacrylate (diPGMA), was synthesised and homo- and co-polymerised for the first time.

Prenatal exposure to glycol ethers and visual contrast sensitivity in 6-year-old children in the PELAGIE mother-child cohort.

Maternal occupational exposure to organic solvents during pregnancy has been associated with decreased visual function in offspring. Glycol ethers (GEs) belong to oxygenated solvents and are widely used both in occupational and domestic contexts. We aimed to assess associations between prenatal GEs exposure and contrast sensitivity in children. Six GE alkoxy carboxylic acidic metabolites (methoxyacetic acid [MAA], ethoxyacetic acid [EAA], ethoxyethoxyacetic acid [EEAA], butoxyacetic acid [BAA], phenoxyacetic acid [PhAA], and 2-methoxypropionic acid [2-MPA]) were measured in first morning void urine samples collected from 220 early-pregnancy women, in the mother-child PELAGIE cohort (France). Trained investigators administered the Functional Acuity Contrast Test (FACT) to the 6-year-old children, providing scores for 5 spatial frequencies (1.5-18 cycles per degree (cpd)). We standardized biomarker urinary concentrations on urine sampling conditions. Values below the LOD were imputed based on log-normal distribution, generating five datasets for multiple imputation. Linear regression models were adjusted for potential confounders. GE metabolites were detected in 70-98% of maternal urine samples. Phenoxyacetic acid (PhAA) had the highest median concentration (0.33mg/L), and 2-methoxypropionic acid (2-MPA) the lowest (0.01mg/L). Children with higher prenatal PhAA concentrations had poorer FACT scores at various spatial frequencies (fourth vs. first quartile: β18cpd=-0.90 (95% confidence interval CI=-1.64, -0.16), β12cpd=-0.92 (95%CI=-1.55, -0.29) and β1.5cpd=-0.69 (95%CI=-1.19, -0.20)). The 2-MPA log-scale concentration was negatively associated with the FACT score at the 3-cpd stimulus. PhAA is the metabolite of ethylene glycol monophenyl ether present in many cosmetics. 2-MPA is the metabolite of an isomer of propylene glycol methyl ether commonly present in household and industrial cleaning products. Although evidence of biological plausibility is lacking, the study suggests adverse impact of ubiquitous prenatal exposure to some GE on visual functioning among children.

Synthesis of core-shell Ce-modified mixed metal oxides derived from P123-templated layered double hydroxides.

Layered double hydroxides are a promising platform material which can be combined with a variety of active species based on their characteristic features. Silicon@P123-templated Ce-doped layered double hydroxide (SiO2@CeMgAl-LDH(P123)) composites were synthesized via a facile in situ co-precipitation method, and characterized by TEM, X-ray diffraction, FTIR, XPS, CO2-, etc. in detail. Meanwhile, the calcined powder (SiO2@CeMgAl-LDO(P123)) possessed an excellent core–shell structure and a high surface area inherited from the LDH structure, which led to an outstanding catalytic activity (99.7% conversion of propylene oxide, 92.4% selectivity of propylene glycol methyl ether) under mild reaction conditions (120 °C). Cerium oxide provides a large number of oxygen vacancies and significantly improves the medium basic strength of the material, which facilitates the selective ring-opening of PO. Furthermore, the introduction and removal of P123 make the cerium oxide uniformly dispersed on the LDH layers, providing more reaction sites for the reaction of methanol and propylene oxide. The core–shell structure prepared by the in situ co-precipitation method could solve the shortcomings of agglomeration of layered double hydroxides and prolong the catalytic life evidently.

Confinement and Processing Can Alter the Morphology and Periodicity of Bottlebrush Block Copolymers in Thin Films.

Bottlebrush block copolymers (BBCPs) are intriguing architectural variations on linear BCPs with highly tunable structure. Confinement can have a significant impact on polymer assembly, giving rise to changes in morphology, assembly kinetics, and properties like the glass transition. Given that confinement leads to significant changes in the persistence length of bottlebrush homopolymers, it is reasonable to expect that BBCPs will see significant changes in their structure and periodicity relative to the bulk morphology. Understanding how confinement influences assembly will be important for designing BBCPs for thin film applications including membranes, integrated photonic structures, and potentially BCP lithography. In order to study the effects of confinement on BBCP conformation and morphology, a blade coating was used to prepare films with continuous variation in film thickness. Unlike thin films of linear BCPs, islands/holes were not observed, and instead mixtures of parallel and perpendicular morphologies emerge after annealing. The lamellar periodicity (L0) of the morphologies is found to be thickness dependent, increasing L0 with decreasing film thickness for blade coated films. Films coated out of tetrahydrofuran (THF) resulted in a single well-defined lamellar periodicity, verified through atomic force microscopy (AFM) and grazing incidence small-angle X-ray scattering (GISAXS), which increases dramatically from the bulk value (30.6 nm) and continues to increase as the film thickness decreases. The largest observed L0 was 65.5 nm, and this closely approaches the estimated upper limit of 67 nm corresponding to a fully extended backbone in a bilayer arrangement. Films coated out of propylene glycol methyl ether acetate (PGMEA) resulted in a mixture of perpendicular lamellae and a smaller, likely cylindrical morphology. The lamellar portion of the film shows the same thickness dependence as the lamellae observed in the THF coated films. The scaling of the lamellar L0 with respect to film thickness follows predictions for confined semiflexible polymers with weak excluded volume interactions and can be related to models for confinement of DNA. Spin coated films shows the same reduction in periodicity, although at very different film thicknesses. This result suggests that the material has shallow free-energy barriers to transitioning between different L0 and morphologies, a property that could be taken advantage of for patterning diverse structures with a single material.

Strategy for Enhancing Ultrahigh-Molecular-Weight Block Copolymer Chain Mobility to Access Large Period Sizes (>100 nm).

Assembling ultrahigh-molecular-weight (UHMW) block copolymers (BCPs) in rapid time scales is perceived as a grand challenge in polymer science due to slow kinetics. Through surface engineering and identifying a nonvolatile solvent (propylene glycol methyl ether acetate, PGMEA), we showcase the impressive ability of a series of lamellar poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) BCPs to self-assemble directly after spin-coating. In particular, we show the formation of large-period (≈111 nm) lamellar structures from a neat UHMW PS-b-P2VP BCP. The significant influence of solvent-polymer solubility parameters are explored to enhance the polymer chain mobility. After optimization using solvent vapor annealing, increased feature order of ultralarge-period PS-b-P2VP BCP patterns in 1 h is achieved. Isolated metallic and dielectric features are also demonstrated to exemplify the promise that large BCP periods offer for functional applications. The methods described in this article center on industry-compatible patterning schemes, solvents, and deposition techniques. Thus, our straightforward UHMW BCP strategy potentially paves a viable and practical path forward for large-scale integration in various sectors, e.g., photonic band gaps, polarizers, and membranes that demand ultralarge period sizes.

Vapor–Liquid Equilibrium for the Binary of Propylene Glycol Methyl Ether Acetate + Ethyl Lactate and Propylene Glycol Methyl Ether + Ethyl Lactate at 101.3 and 20.0 kPa

In this work, the vapor–liquid equilibrium (VLE) data of propylene glycol methyl ether acetate + ethyl lactate and propylene glycol methyl ether + ethyl lactate was determined by a modified Rose–Wi...

Synthesis of propylene glycol methyl ether catalyzed by imidazole polymer catalyst: Performance evaluation, kinetics study, and process simulation

An imidazole polymer (divinylbenzene-vinylimidazole) catalyst (P-DVB-VIM) was developed for production of the eco-friendly solvent propylene glycol methyl ether (PGME) by the propoxylation reaction of propylene oxide (PO) with methanol (ME). The catalyst was characterized in detail by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analysis. 1H NMR was used to characterize the structural features of the catalyst precursor, i.e., the linear polymer of vinylimidazole (PVIM). An “electrophile nucleophile dual activation” ring-opening mechanism was proposed based on the “cooperative effect” of the reactant and PVIM. The catalytic performance was investigated and optimized at 100–130 ℃ using an autoclave batch reactor. The results reveal that the P-DVB-VIM shows excellent catalytic performance, exhibiting the highest turnover frequency (TOF) number at 120 °C within 45 min. The reaction kinetics was systematically studied using the pseudohomogeneous (PH) kinetic model. The kinetic parameters were determined by non-linear regression analysis of the experimental data. Validation of the model showed that the experimental data were in good agreement with the predicted outcomes. Moreover, based on the proposed kinetic model, steady-state simulations of the production of PGME in a fixed-bed reactor were carried out to determine the optimal design parameters, thus providing a useful guide for the design and production of PGME on the industrial scale.

A versatile approach for preparing stable and high concentration liquid metal nanoparticles on a large scale

Liquid metal is increasingly attracting attention because of the fluidity properties and the electrical and thermal conductivity of metals. However, the preparation of stable liquid metal nanoparticles (LM NPs) is facing a great challenge. Liquid metal is prone to be oxidized when exposed to water and air. Because of the high density and surface tension, liquid metal tends to aggregate and precipitate. To address this challenge, we have developed a grinding technology that not only produces LM NPs with a narrower size distribution but also has high production efficiency and high concentration (more than 10 wt.%). A new polymer was synthesized to reduce the particle size and stabilize the NPs during the grinding process. The LM NPs stabilized with comb-like polymer have a smaller diameter of about 120 nm in deionized water and 80 nm in propylene glycol methyl ether (PM), which can maintain relative stability for a period of >90 days. The high concentration LM NPs play an important role in the fields of electronic product cooling, biomedicine, tissue engineering, intelligent hardware, 3 D printing, flexible electronics, artificial intelligence, aerospace, and so on.

Different morphologies of SiO2@Mg-Al-LDH nanocomposites as catalyst for the synthesis of propylene glycol methyl ether

Layered double hydroxide (LDH) has been recognized as one type of the most promising shell material. In this contribution, SiO2@Mg-Al-LDH core-shell nanocomposites with different shell morphologies were prepared and characterized via XRD, SEM, TEM, FT-IR, TG-DTA, and BET in detail. The as-prepared SiO2@LDHs exhibit different base catalysis for the synthesis of propylene glycol monomethyl ether (PGME). The results indicate that LDH shell oriented vertically on the core could be generated by the sol-gel method (SG-SiO2@LDH) and displays the highest catalytic activity and stability among three materials. The horizontally oriented shell morphology tends to be formed by the self-assembly method (SA-SiO2@LDH), which maintains the original LDH structure but unstable. The formation of a third morphology called mixed platelet is contributed to the coexistence of horizontally and vertically platelets. It has been seen in the case of co-precipitation (CP-SiO2@LDH). Integrating the experimental result analysis, synthesis methods can significantly influence the nucleation rate, which would fabricate different shell morphologies. Furthermore, core-shell nanomaterials with special morphology may have certain application prospects in solid catalysis.

Mechanism of a catalytic silver(I)-complex: assisted electroless deposition of inductance coil on poly(ethylene terephthalate) film

In this work, silver nitrate, thiourea, bisphenol A diglycidyl ether (BADGE), and propylene glycol methyl ether (PM) were selected for designing a silver(I)-complex to trigger the deposition of inductance coil on PET film through electroless copper plating. The most stable silver(I)-complex structure is formed when the ratio of thiourea molecules and silver ions is 3 to 1 by quantum chemical calculations based on density functional theory (DFT). Meanwhile, XRD test demonstrates that the white precipitate crystallized from PM solution of thiourea and silver nitrate is [Ag(SC(NH2)2)3]NO3, which is consistent with theoretical calculations. The cross section of PET film with copper patterns and interconnection holes characterized by metallurgical microscope proves that the silver(I)-complex is able to initiate copper deposition on the surface and through hole wall of PET film. The measured inductance values at operating frequency from 1 to 50 MHz indicate that the fabricated flexible inductor is capable of being integrated into flexible electronics when the bending angles are within 45°. Additionally, the inductor can also be utilized as an angel sensor when the bending angles are in the range of 60° to 180° at 10 MHz.

Multiphase equilibria of binary and ternary mixtures containing water, propylene glycol methyl ether, and propylene glycol methyl ether propionate

Vapor-liquid equilibrium (VLE) and vapor-liquid-liquid equilibrium (VLLE) data were measured for the binary and ternary systems of propylene glycol methyl ether (PGME) + propylene glycol methyl ether propionate (PGMEP), water + PGMEP and water + PGME + PGMEP using a static-type apparatus equipped with a visual cell under isothermal condition over a temperature range of 318.15 K–363.15 K. The phase equilibrium data of the binary systems are correlated well with the NRTL-HOC and the UNIQUAC-HOC models by using linearly temperature-dependent parameters. However, the ternary VLLE properties are unable to be estimated accurately only by using the parameters determined from the phase equilibrium data of the constituent binaries. The representation of the ternary VLLE properties can be substantially improved as the six model parameters are determined simultaneously from the ternary VLLE data.