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DF: Fachverband Dielektrische Festkörper

DF 10: Dielectric surfaces and interfaces

DF 10.1: Hauptvortrag

Mittwoch, 24. März 2010, 14:00–14:40, H11

Molecular self-assembly on calcite — •Angelika Kühnle, Philipp Rahe, Jens Schütte, and Sebastian Rode — Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, 55099 Mainz

Calcite, the most stable polymorph of CaCO₃, is one of the most abundant minerals on earth that plays a crucial role in a variety of different fields such as biomineralization and environmental geochemistry. Moreover, calcite precipitates upon scaling, a process that is deliberately prevented by polyelectrolyte addition in many daily life as well as industrial applications such as laundry and water desalination.

Consequently, the (1014) calcite cleavage plane as well as molecule adsorption onto calcite (1014) has attracted great attention. Despite this, a controversy exists as to whether the (1014) cleavage plane of calcite reconstructs or not. Atomically resolved scanning force microscopy images taken in liquids will be presented, revealing a bulk-truncated (1x1) surface. When imaged under ultra-high vacuum conditions, however, clear experimental evidence is provided for a (2x1) reconstruction.

Self-assembly of different functionalized organic molecules on calcite will be reported, demonstrating the formation of both, two-dimensional ordered molecular layers as well as uni-directional wire-like structures.