Thermodiffusion of sodium polystyrene sulfonate in a supporting electrolyte

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • University of Valencia


Thermodiffusion, or the Soret phenomenon, is well understood in simple systems, but in multicomponent and polyvalent electrolyte systems the process becomes more complicated due to the coupling of fluxes. We experimentally investigate the time evolution of a concentration gradient generated by thermodiffusion of a polyelectrolyte (poly(sodium 4-styrene sulfonate), NaPSS) in a 1:1 supporting electrolyte. We also derive and solve the transport equations that are used to extract the Soret coefficient from the experimental observations. It is shown that NaPSS thermodiffusion in NaCl is strongly dependent on concentration, with almost 100% thermal separation in concentrations below 15 nmol L−1. Moreover, the results suggest that the supporting electrolyte can greatly influence the thermodiffusion of the polyelectrolyte, in some cases possibly even reversing the direction of the flux from the usual case of enrichment at the cold side.


Original languageEnglish
Pages (from-to)542-550
Number of pages9
JournalElectrochimica Acta
Publication statusE-pub ahead of print - 1 Jun 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Non-isothermal process, Polyelectrolyte, Soret effect, Thermodiffusion

ID: 34995200