Berlin 2015 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 38: Electrolytes at Interfaces - Stern Layer (focus session, joint CPP/BP/O)

BP 38.1: Hauptvortrag

Mittwoch, 18. März 2015, 15:00–15:30, C 130

Ultraslow dynamics of hydrated metal ions at the water-solid interface observed by atomic force microscopy — •Kislon Voitchovsky — Durham University, Durham, UK

The lateral organisation and dynamics of ions in the Stern layer of immersed solids is central to many electrochemical and biological processes. However, measuring the lateral organisation and dynamics of single adsorbed ions remains challenging experimentally. Recently we showed that atomic force microscopy could be used to image single metal ions at the surface of various solids in water [1, 2]. Our results indicate that, depending on the hydration landscape of the solid, adsorbed ions can form ordered structures within the Stern layer, through correlation effects that are driven purely by the interfacial water [2]. The dynamics of the adsorbed ions appears surprisingly slow, typically exhibiting residence times above the millisecond. This suggests that water can also dramatically alter the ions dynamics and play a key role in stabilizing adsorbed ions at a given location of the interface. The existence of long-lived ionic structures at interfaces could have important implications for charge transfer and at biointerfaces.

[1] M. Ricci, P. Spijker, F. Stellacci, J.-F. Molinari, K. Voitchovsky, Langmuir, 29, 2207 (2013) [2] M. Ricci, P. Spijker, K. Voitchovsky, Nature Commun., 5, 4400 (2014)