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arXiv · 1401.7242

Specific Salt Effects on Thermophoresis of Charged Colloids

Kyriakos A. Eslahian·Arghya Majee·Michael Maskos·Alois Würger
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Abstract

We study the Soret effect of charged polystyrene particles as a function of temperature and electrolyte composition. As a main result we find that the Soret coefficient is determined by charge effects, and that non-ionic contributions are small. In view of the well-kown electric-double layer interactions, our thermal field-flow fractionation data lead us to the conclusion that the Soret effect originates to a large extent from diffusiophoresis in the salt gradient and from the electrolyte Seebeck effect, both of which show strong specific-ion effects. Moreover, we find that thermophoresis of polystyrene beads is fundamentally different from proteins and aqueous polymer solutions, which show a strong non-ionic contribution.

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Kyriakos A. Eslahian, Arghya Majee, Michael Maskos, Alois Würger. 2014-01-28. Specific Salt Effects on Thermophoresis of Charged Colloids. https://doi.org/10.1039/c3sm52779d

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