Berlin 2018 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 71: Poster: Noneq. Stat. Phys., Stoch. Thermo, Brownian Dyn.

DY 71.10: Poster

Donnerstag, 15. März 2018, 15:30–18:00, Poster A

Thermophoresis of Charged Colloids in Electrolyte Solutions — •Martin Fränzl and Frank Cichos — Molecular Nanophotonics Group, Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Germany

In the last decades thermophoresis of colloids was mainly discussed in terms of thermoosmotic pressure. However, in the recent years it has become clear that, for charged systems in an electrolyte solution the thermoelectric or Seebeck effect may provide an additional non-local driving force. In a non-uniform temperature, positive and negative ions, dissolved in water, have the tendency to migrate towards colder regions. However, in general one of the ion species is moving more rapidly, resulting in a thermoelectric field between the hot and the cold boundary. This field can drive charged colloids to the hot or to the cold, depending on the sign of the electrolyte Seebeck coefficient. The present work investigates the thermoelectric effects by locally heating a gold film with a focused laser beam within a colloidal suspension and discusses the resulting colloidal transport.