Transport properties of the binary mixtures of the three organic liquids toluene, methanol, and cyclohexane

We report on the measurements of diffusion (D), thermodiffusion (DT), and Soret (ST) coefficients in binary pairs of the ternary system toluene-methanol-cyclohexane using different instrumental techniques: microgravity measurements (SODI/DCMIX2) on the International Space Station, thermogravitational column in combination with sliding symmetric tubes, optical beam deflection, optical digital interferometry, and counter flow cell. The binary systems have large regions where the mixtures are either not miscible or the Soret coefficient is negative. All the coefficients have been measured over a wide composition range with the exception of a miscibility gap. Results from different instruments and literature data are in favorable agreement over a broad composition range. Additionally, we have carefully measured the physical properties and the optical contrast factors (dn/dc) p, T and (dn/dT)p,c. The latter ones were also calculated using the Looyenga equation. The measurements in methanol-cyclohexane mixture revealed a decay of the diffusion coefficient when approaching the miscibility gap. We have interpreted this in the spirit of the pseudospinodal concept

Thermodiffusion Coefficients of Water/Ethanol Mixtures for Low Water Mass Fractions

The difficulty of measuring the thermodiffusion coefficients by optical properties of water-ethanol binary mixtures of approximately 20 wt % of water has been highlighted by several authors in recent years. This is because the concentration derivative of the refractive index (∂ n/∂ c) p,T is near zero at this concentration. For this reason, we measured the thermodiffusion coefficients by means of density analysis using the thermogravitational column technique from 5 wt % to 50 wt % at 25∘C. In addition, we measured the thermophysical properties such as density, dynamic viscosity, thermal expansion and mass expansion

Thermodiffusion in Ternary Mixtures of Water/Ethanol/Triethylene Glycol: First Report on the DCMIX3-Experiments Performed on the International Space Station

We report on thermodiffusion experiments conducted on the International Space Station ISS during fall 2016. These experiments are part of the DCMIX (Diffusion and thermodiffusion Coefficients Measurements in ternary Mixtures) project, which aims at establishing a reliable data base of non-isothermal transport coefficients for selected ternary liquid mixtures. The third campaign, DCMIX3, focuses on aqueous systems with water/ethanol/triethylene glycol as an example, where sign changes of the Soret coefficient have already been reported for certain binary subsystems. Investigations have been carried out with the SODI (Selectable Optical Diagnostics Instrument) instrument, a Mach-Zehnder interferometer set up inside the Microgravity Science Glovebox in the Destiny Module of the ISS. Concentration changes within the liquids have been monitored in response to an external temperature gradient using phase-stepping interferometry. The complete data set has been made available in spring 2017. Due to additionally available measurement time, it was possible to collect a complete data set at 30∘C and an almost complete data set at 25∘C, which significantly exceeds the originally envisaged measurements at a single temperature only. All samples could be measured successfully. The SODI instrument and the DCMIX experiments have proven reliable and robust, allowing to extract meaningful data even in case of unforeseen laser instabilities. First assessments of the data quality have revealed six out of 31 runs with some problems in image contrast and/or phase step stability that will require more sophisticated algorithms. This publication documents all relevant parameters of the conducted experiments and also events that might have an influence on the final results. The compiled information is intended to serve as a starting point for all following data evaluations

The Soret coefficients of the ternary system water/ethanol/triethylene glycol and its corresponding binary mixtures

Thermodiffusion in ternary mixtures is considered prototypic for the Soret effect of truly multicomponent systems. We discuss ground-based measurements of the Soret coefficient along the binary borders of the Gibbs triangle of the highly polar and hydrogen bonding ternary DCMIX3-system water/ethanol/triethylene glycol. All three Soret coefficients decay with increasing concentration, irrespective of the choice of the independent component, and show a characteristic sign change as a function of temperature and/or composition. With the exception of triethylene glycol/ethanol at high temperatures, the minority component always migrates toward the cold side. All three binaries exhibit temperature-independent fixed points of the Soret coefficient. The decay of the Soret coefficient with concentration can be related to negative excess volumes of mixing. The sign changes of the Soret coefficients of the binaries allow to draw far-reaching conclusions about the signs of the Soret coefficients of the corresponding ternary mixtures. In particular, we show that at least one ternary composition must exist, where all three Soret coefficients vanish simultaneously and no steady-state separation is observable

Digital Interferometry Applied to Thermogravitational Technique

In this work, we have applied Optical Digital Interferometry approach to thermogravitational micro-column technique. By the new analysis, we examine the entire height of the micro-column and determine the complete concentration profile inside. The measurements were carried out by two lasers with different wavelength λ = 633nm and λ = 470nm. The system was validated with binary subsystems of the THN-IBB-C12 ternary mixture at equal mass fractions. The results were compared with values of Benchmark Fontainebleau and they showed an excellent agreement

Elektrospinning bidezko PCL nanozuntzen lorpena larruazal-birsorkuntzarako

Skin ulcers are a serious threat to public health system, and, although wound healing is a natural process, a proper dressing can improve the healing process. In this work, platelet rich plasma (PRP) coated polycaprolactone (PCL) wound dressings have been designed by means of electrospinning. PCL is a biocompatible and biodegradable synthetic polymer. PRP, in turn, offers growth factors to the dressing, which are significant in the healing. To enable an effective addition of PRP, functionalization of PCL fibre meshes has been carried out by immersing them in alkaline dissolution of different concentrations. In this way, a novel wound dressing that aids in the regeneration of damaged skin layers has been developed.Larruazal-ultzerak osasun publikoarentzat mehatxu larriak dira, eta zaurien orbaintzea prozesu naturala bada ere, zauri-jantzi egoki batek prozesuan lagundu dezake. Lan honetan, elektrospinning teknika bitartez, polikaprolaktonazko (PCL) zauri-jantziak diseinatu dira, zeinei plaketan aberatsa den plasma (PRP) estaldura gehitu zaie. PCL biobateragarria eta biodegradagarria den polimero sintetikoa da. PRPak aldiz, lesioa sendatzeko oso garrantzitsuak diren hazkunde-faktoreak eskaintzen dizkio zauri-jantziari. PRParen adizio eraginkorra ahalbidetzeko, PCLezko zuntz-sareen funtzionalizazioa burutu da hau kontzentrazio desberdineko disoluzio alkalinoetan murgilduz. Horrela, kaltetutako azalgeruzen birsortzea eragingo duen zauri-jantzia garatu da

Digital Interferometry Applied to Thermogravitational Technique

In this work, we have applied Optical Digital Interferometry approach to thermogravitational micro-column technique. By the new analysis, we examine the entire height of the micro-column and determine the complete concentration profile inside. The measurements were carried out by two lasers with different wavelength λ = 633nm and λ = 470nm. The system was validated with binary subsystems of the THN-IBB-C12 ternary mixture at equal mass fractions. The results were compared with values of Benchmark Fontainebleau and they showed an excellent agreement.SCOPUS: ar.jinfo:eu-repo/semantics/publishe