Impurity effects at hydrophobic surfaces

Yuki Uematsu, Douwe Jan Bonthuis, Roland R. Netz

研究成果: ジャーナルへの寄稿評論記事

9 引用 (Scopus)

抜粋

The effective charge of hydrophobic surfaces and in particular of the air–water interface is a crucial parameter for electrochemistry, colloidal chemistry and interfacial science, but different experiments give conflicting estimates. Zeta-potential and disjoining-pressure measurements point to a strongly negative surface charge, often interpreted as being due to adsorbing hydroxide ions. In contrast, surface tension measurements of acids and bases suggest the hydronium ion to be surface active, in agreement with some surface-specific non-linear spectroscopy results. The air–electrolyte interfacial tension exhibits a characteristic minimum at millimolar electrolyte concentration for all salts, the so-called Jones–Ray effect, which points to competitive adsorption mechanisms present in dilute electrolyte solutions. We show that all these puzzling experimental findings can be explained by the presence of trace amounts of surface-active charged impurities, most likely anionic surfactants.

元の言語英語
ページ(範囲)166-173
ページ数8
ジャーナルCurrent Opinion in Electrochemistry
13
DOI
出版物ステータス出版済み - 2 2019

    フィンガープリント

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Electrochemistry

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