Dresden 2017 – scientific programme

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O: Fachverband Oberflächenphysik

O 9: Solid-Liquid Interfaces: Structure, Spectroscopy I

O 9.7: Talk

Monday, March 20, 2017, 12:00–12:15, WIL C307

Understanding water relaxation at interfaces — •Dominika Lesnicki and Marialore Sulpizi — Department of Physics, Johannes Gutenberg University, Staudingerweg 7, 55128 Mainz, Germany

Advances in ultrafast spectroscopy allow to study vibrational energy transfer of water molecules at interfaces. In the case of water-air interface, it has been shown that the vibrational energy relaxation dynamics is significantly different from that of bulk water.

Here we propose a method to understand vibrational energy relaxation time scales and pathways of the OH stretching mode of water, which is based on the calculation of vibrational response function and the direct simulation of the energy relaxation processes using density functional theory based molecular dynamics (DFTMD) simulations, where a consistent treatment of the electronic structure of solvent and surface is provided.

We apply our method to the fluorite/water interface as function of pH. This system shows a fast relaxation, at low pH, similar to that of bulk water, and a slow relaxation at hight pH. Direct comparison to the experimental results is also possible thanks to the collaboration with the molecular spectroscopy group of E. Backus at MPIP.