Regensburg 2019 – wissenschaftliches Programm
CPP 25.4: Poster
Dienstag, 2. April 2019, 14:00–16:00, Poster B1
The Soret effect in ternary mixtures of water + ethanol + triethylene glycol of equal mass fractions: ground and microgravity experiments — •Daniel Sommermann1, Thomas Triller1, Marcel Schraml1, Felix Sommer1, Werner Köhler1, Estela Lapeira2, and Mounir M. Bou-Ali2 — 1Physikalisches Institut, Universität Bayreuth, Germany — 2Mechanical and Manufacturing Department, MGEP Mondragon, Spain
Measurements of the Soret and thermodiffusion coefficients of a symmetric ternary mixture with equal mass fractions of water, ethanol, and tri-ethylene glycol have been performed by two-color optical beam deflection and the thermogravitational column technique in the laboratory and under microgravity conditions in the SODI apparatus aboard the ISS. The results from all three experimental techniques agree within the experimental error bars. The agreement with the microgravity results shows that thermosolutal convection could be well controlled in the 2-OBD experiments by a proper orientation of the temperature gradient. Based on the orientation of the confidence ellipsoid, not all coefficients are equally affected by experimental errors. Although there are appreciable uncertainties for water and ethanol, the Soret and the thermodiffusion coefficients of tri-ethylene glycol could be obtained with a good accuracy. We have found that water behaves thermophobic, whereas both ethanol and tri-ethylene glycol are thermophilic with negative Soret coefficients.
 T.Triller et al., Eur. Phys. J. E, submitted 2018