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Updated: Jul 10, 2026
10:28
Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
Ions at aqueous interfaces: from water surface to hydrated proteins
Pavel Jungwirth1, Bernd Winter
1Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Complex Molecular Systems and Biomolecules, 16610 Prague 6, Czech Republic. pavel.jungwirth@uochb.cas.cz
Annual Review of Physical Chemistry
|November 23, 2007
Summary
Ions, traditionally absent from solution surfaces, are surprisingly abundant at the air/water interface. This study reviews their behavior and explores ion interactions at protein-water interfaces.
Area of Science:
- Physical Chemistry
- Surface Science
- Computational Chemistry
Background:
- Traditionally, aqueous solution surfaces were considered ion-free.
- Recent molecular simulations and spectroscopy reveal significant ion presence at interfaces.
- Large, polarizable anions and hydronium cations are key players in air/water interface chemistry.
Purpose of the Study:
- To review recent findings on ions at the air/water interface.
- To compare ion behavior in water with other polar solvents.
- To investigate ion segregation at protein/water interfaces and compare with air/water interfaces.
Main Methods:
- Review of molecular simulations.
- Analysis of surface-selective spectroscopic techniques.
- Investigation of dielectric models for protein/water interfaces.
Main Results:
- Ions, particularly hydronium and hydroxide, are present and enhanced at the water surface.
- Ion segregation at protein/water interfaces shows little correlation with air/water interfaces.
- A local model of ion pairing with protein surface groups is proposed.
Conclusions:
- The air/water interface is chemically active due to ion presence.
- Protein/water interfaces exhibit distinct ion segregation patterns compared to air/water interfaces.
- A local ion-pairing model effectively describes ion interactions at protein surfaces.
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