Charged Surface-Active Impurities at Nanomolar Concentration Induce Jones-Ray Effect

Yuki Uematsu, Douwe Jan Bonthuis, Roland R. Netz

Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

Abstract

The electrolyte surface tension exhibits a characteristic minimum around a salt concentration of 1 mM for all ion types, known as the Jones-Ray effect. We show that a consistent description of the experimental surface tension of salts, bases, and acids is possible by assuming charged impurities in the water with a surface affinity typical for surfactants. Comparison with experimental data yields an impurity concentration in the nanomolar range, well below the typical experimental detection limit. Our modeling reveals salt-screening enhanced impurity adsorption as the mechanism behind the Jones-Ray effect: for very low salt concentration added salt screens the electrostatic repulsion between impurities at the surface, which dramatically increases impurity adsorption and thereby reduces the surface tension.

Originalspracheenglisch
Seiten (von - bis)189-193
Seitenumfang5
FachzeitschriftJournal of Physical Chemistry Letters
Jahrgang9
Ausgabenummer1
DOIs
PublikationsstatusVeröffentlicht - 4 Jan 2018
Extern publiziertJa

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ASJC Scopus subject areas

  • !!Materials Science(all)

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