| AVS 55th International Symposium & Exhibition | |
| Surface Science | Friday Sessions |
| Session SS+AS+NC-FrM |
| Session: | Environmental Surfaces and Water Interaction with Oxide Surfaces |
| Presenter: | M. Valtiner, Max-Planck-Institut für Eisenforschung, Germany |
| Authors: | M. Valtiner, Max-Planck-Institut für Eisenforschung, Germany G. Grundmeier, University of Paderborn, Germany |
| Correspondent: | Click to Email |
The surface chemistry at oxide/water interfaces is a key issue in adhesion science and related areas such as corrosion science. De-adhesion processes as well as corrosion processes are often accompanied by a change of the pH at the interface. Hence an atomistic understanding of oxide dissolution promoting effects of H+, OH- and anions, as chlorides or sulfates, are an important aspect of de-/adhesion, metal corrosion and its inhibition. In this context, experimental results on single crystalline ZnO(0001)-Zn model surfaces and DFT-based ab-initio studies will be discussed. First, it will be shown that single crystalline ZnO(0001)-Zn model surfaces can be prepared easily and surprisingly clean under ambient conditions by introducing hydroxide stabilization via a wet chemical etching step. The prepared model surfaces will be discussed by AFM, LEED, angle resolved XPS, ToF-SIMS and Auger spectroscopy data.1 Secondly, the stability of these ZnO(0001)-Zn surfaces in electrolyte solutions will be demonstrated by a combined approach of in-situ AFM imaging and ex-situ LEED investigations. It will be shown that ZnO(0001)-Zn surfaces are stable and single crystalline in aqueous solutions within a wide pH range due to hydroxide stabilization. An in-situ AFM study of the acidic dissolution allowed an imaging of the dissolution process and hence a mechanistic understanding of the dissolution process of ZnO can be supported.2 Moreover, Single Molecule Adhesion studies - by means of single molecule de-sorption of polyelectrolyte molecules - on these surfaces at variation of the pH level will be presented. Finally, the potential of a synergistic combination of these approaches with ab-initio based simulation methods will be highlighted.
1M. Valtiner, S. Borodin, G. Grundmeier; Physical Chemistry Chemical Physics, 9(19), (2007) 2406-2412.
2M. Valtiner, S. Borodin, G. Grundmeier; Langmuir (2008), ASAP Article: 10.1021/la7037697.