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

2021 ◽  
Vol 44 (10) ◽  
Author(s):  
M. Schraml ◽  
H. Bataller ◽  
C. Bauer ◽  
M. M. Bou-Ali ◽  
F. Croccolo ◽  
...  
Keyword(s):  
Soret Effect ◽  
Triethylene Glycol ◽  
Ternary Mixtures ◽  
Soret Coefficient ◽  
Cold Side ◽  
Gibbs Triangle ◽  
Sign Change ◽  
Volumes Of Mixing ◽  
System Water ◽  
State Separation

Abstract 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. Graphic abstract

Thermal Diffusion in Molten Binary Mixtures of Silver Nitrate with Alkali Nitrates

1967 ◽  
Vol 22 (4) ◽  
pp. 471-476 ◽  
Author(s):  
Villy Backlund ◽  
Josette Dupuy ◽  
Silas Gustafsson ◽  
Arnold Lundén
Keyword(s):  
Steady State ◽  
Thermal Diffusion ◽  
Isotope Effects ◽  
Temperature Gradients ◽  
Convection Cell ◽  
Soret Coefficient ◽  
Horizontal Temperature Gradient ◽  
Vertical Temperature ◽  
Cold Side ◽  
State Separation

Thermal diffusion in the molten systems LiNO3—AgNO3, KNO3—AgNO3, RbNO3—AgNO, and CsNO3—AgNO3 was detected by means of chemical analysis. Two types of cells were used: the elementary effect was measured directly in cells with vertical temperature gradients, and the coefficient of thermal diffusion (D') was estimated from the steady-state separation obtained in convection cells (horizontal temperature gradient). A discussion of possible sources of error shows for both methods that the results might be systematically lower than corresponding to ideal conditions. In all systems AgNO3 was enriched at the cold side. There are indications that the SORET-coefficient varies with the composiiton of the mixture and the temperature. Thus for the LiNO3— AgNO3 system, depending on the conditions, the SORET coefficient ranged from 2 × 10-3 to 5.5 × 10-3 degr.-1, while it was about 1.8 × 10-3-5 degr.-1 over a wide concentration range for the KNO3—AgNO3 system, and about 1.3 × 10-3 degr.-1 over the investigated ranges for the RbNO3—AgNO3 and CsNO3—AgNO3 systems.Also isotope effects were measured with the convection cell, giving SoRET-coefficients of the order of 10-5 to 4 × 10-5 degr.-1 for 6Li—7Li as well as for 39K—-41K, which is in agreement with previous investigations.

Determination of thermodynamic and microscopic origins of the Soret effect in sodium silicate melts: Prediction of sign change of the Soret coefficient

2021 ◽  
Vol 154 (7) ◽  
pp. 074501
Author(s):  
Masahiro Shimizu ◽  
Tsubasa Fukuyo ◽  
Jun Matsuoka ◽  
Kento Nakashima ◽  
Kenzo Sato ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Soret Effect ◽  
Silicate Melts ◽  
Soret Coefficient ◽  
Sign Change

Numerical Analysis of Thermal-Solutal Convection in Heterogeneous Porous Media

2005 ◽  
Vol 73 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Charles-Guobing Jiang ◽  
M. Ziad Saghir ◽  
M. Kawaji
Keyword(s):  
Porous Media ◽  
Thermal Diffusion ◽  
Soret Effect ◽  
Heterogeneous Porous Media ◽  
Soret Coefficient ◽  
Solutal Convection ◽  
Coefficient Distribution ◽  
Separation Ratio ◽  
Diffusion In Porous Media ◽  
Vertical Cavity

Thermal diffusion, or Soret effect, in porous media is mathematically modeled with the Firoozabadi model based on non-equilibrium thermodynamics. The Soret effect in a binary mixture is investigated in a vertical cavity with heterogeneous permeability, where natural convection can occur. The thermo solutal convection with heterogeneous permeability was studied in terms of flow pattern, concentration distribution, component separation ratio, and Soret coefficient distribution. A consistent analysis was conducted and it is concluded that the Soret coefficient of thermal diffusion in porous media strongly depends on the heterogeneity of permeability.

scholarly journals Thermophoresis: The Case of Streptavidin and Biotin

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 376 ◽  
Author(s):  
Doreen Niether ◽  
Mona Sarter ◽  
Bernd W. Koenig ◽  
Jörg Fitter ◽  
Andreas M. Stadler ◽  
...  
Keyword(s):  
Heavy Water ◽  
Rayleigh Scattering ◽  
Soret Effect ◽  
Binding Constants ◽  
Soret Coefficient ◽  
Protein Solutions ◽  
Elastic Neutron ◽  
Solvent Interactions ◽  
Free Protein ◽  
Promising Tool

Thermophoretic behavior of a free protein changes upon ligand binding and gives access to information on the binding constants. The Soret effect has also been proven to be a promising tool to gain information on the hydration layer, as the temperature dependence of the thermodiffusion behavior is sensitive to solute–solvent interactions. In this work, we perform systematic thermophoretic measurements of the protein streptavidin (STV) and of the complex STV with biotin (B) using thermal diffusion forced Rayleigh scattering (TDFRS). Our experiments show that the temperature sensitivity of the Soret coefficient is reduced for the complex compared to the free protein. We discuss our data in comparison with recent quasi-elastic neutron scattering (QENS) measurements. As the QENS measurement has been performed in heavy water, we perform additional measurements in water/heavy water mixtures. Finally, we also elucidate the challenges arising from the quantiative thermophoretic study of complex multicomponent systems such as protein solutions.

Numerical Analysis of Ludwig-Soret Effect of One Binary Mixture and Two Ternary Mixtures in an Al2O3 Porous Cavity

2006 ◽  
Author(s):  
T. J. Jaber ◽  
M. Z. Saghir
Keyword(s):  
Porous Medium ◽  
Steady State ◽  
Numerical Analysis ◽  
Binary Mixture ◽  
Ternary Mixture ◽  
Soret Effect ◽  
Ternary Mixtures ◽  
Thermosolutal Convection ◽  
Left Wall ◽  
Porous Cavity

A cavity of 10 mm in width, 10 mm in height, and 32.1 mm in horizontal length filled with Al2O3 porous medium designed in Pau project to investigate thermal diffusion phenomena, or Ludwig-Soret effect. A lateral heating condition was applied with 10 °C at the left wall and 50 °C at the right wall. The thermosolutal convection of a binary mixture of water-ethanol at 75.0 MPa pressure, a ternary mixture with methane, n-butane, and n-dodecan at 35.0 MPa pressure, and a ternary mixture of n-dodecane, isobutylbenzene, and tetrahydonaphthalene at atmosphere pressure inside the Al2O3 porous medium cavity were numerically investigated. The thermal conductivity and the permeability of Al2O3 porous medium on the Ludwig-Soret effect were analyzed, the former had little influence, but the later had strong impact on the compositional separation at the steady state of thermosolutal convection, which were analyzed globally with separation ratio. The distributions of component mole fraction(s) on the horizontal and vertical lines in the center of the porous cavity were also shown to study the details of the compositional separation at the steady state of thermosolutal convection. Recommendations are made for the experimental design based on the results of numerical analysis

The Soret Effect: A Review of Recent Experimental Results

2005 ◽  
Vol 73 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Jean K. Platten
Keyword(s):  
Rayleigh Scattering ◽  
Soret Effect ◽  
Organic Liquid ◽  
Oil Industry ◽  
Liquid Mixtures ◽  
Beam Deflection ◽  
Soret Coefficient ◽  
Onset Of Convection ◽  
New Techniques ◽  
Scattering Technique

In the first part of the paper, we recall what the Soret effect is, together with its applications in science and industry. We emphasize the need to have a reliable data base for the Soret coefficient. Next we review the different techniques to measure the Soret coefficient (elementary Soret cell, beam deflection technique, thermal diffusion forced Rayleigh scattering technique, convective coupling and, in particular, the onset of convection in horizontal layers and the thermogravitational method). Results are provided for several systems, with both negative and positive Soret coefficients, and comparison between several laboratories are made for the same systems. We end with “benchmark” values of the Soret coefficient for some organic liquid mixtures of interest in the oil industry and to which all future new techniques should refer before gaining confidence. We conclude that correct values of the Soret coefficient can be obtained in earth conditions and we deny the need to go to microgravity.

scholarly journals Soret and Diffusion Coefficients Measurement for Binary and Ternary Mixtures on Board the International Space Station Using SODI Apparatus

2021 ◽  
Author(s):  
Amirhossein Ahadi
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
International Space Station ◽  
Diffusion Coefficients ◽  
Space Station ◽  
Ternary Mixtures ◽  
Soret Coefficient ◽  
International Space ◽  
Binary And Ternary Mixtures ◽  
Maximum Separation

Thermodiffusion or Soret effect is a heat and mass transfer phenomenon in a non-isothermal liquid and gas mixtures. This phenomenon is more pronounced in oil fields, usually due to the porous environment. A precise and better understanding of the thermodiffusion phenomena in multi-component mixtures results in a more accurate modeling of oil reservoirs. Accordingly, the main objective of this study is to investigate the thermodiffusion phenomenon in the multicomponent mixtures. In order to achieve this objective, two series of thermodiffusion experiments conducted on board the International Space Station (ISS) using the SODI (Selectable Optical Diagnostics Instrument) facility were analyzed. The first series of experiments aimed to study the effects of the forced vibration on the Soret phenomena. The experimental mixture was water and isopropanol with different compositions subjected to various temperature gradients normal to the vibrations. Results revealed maximum separation for the case with the minimum vibration and the lower temperature gradient; however, a linear relationship between Gershuni number and maximum separation was not found. On the other hand, the second series of experiment was aimed to the measurement of the diffusion coefficients of selected ternary mixtures. Mixtures of tetrahydronaphthalene-isobutylbenzene-dodecane at five different compositions were hosted in the DSC (Diffusion and Soret Coefficient) cell array. Thus, the Soret diffusion coefficients and the molecular diffusion coefficients of the mentioned hydrocarbon mixture at five different compositions have been reported. To process the results of these experiments an advance image processing technique was developed and implemented in an application with GUI (Graphical User Interface) for the Mach-Zehnder interferometer (MZI). Then, the application of the windowed Fourier transformation (WFT) to analyze the heat and mass transfer problem using the MZI setup is proposed. Results show that the WFT noticeably improves the measurement of concentration. This improvement is more evident for the ternary. It was shown that about 10% underestimation of the Soret coefficient would be resulted; if an accurate determination of the thermal time for the MZI is not used. The reliability and the repeatability of the MZI apparatus on board ISS to study thermodiffusion for binary and ternary mixtures were shown.

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