| Mineral surfaces are reactive transformation centres and sinks for gases, solutes and solvents.
Under environmental conditions these surfaces are populated by (hydr)oxo functional
groups that can undergo protonation, ligand exchange, and form intricate networks of
hydrogen bonds. Knowledge of the types, distributions and orientations of these groups
is essential for understanding molecular-scale processes taking place at mineral
surfaces.
This work is focused on the properties of hydroxo groups on important crystallographic
planes of synthetic nano-sized iron and aluminum (oxyhydr)oxides exposed to vacuum, water
vapor and/or carbon dioxide. Vibration spectroscopic signatures of hydroxo groups on
these minerals will be presented alongside predictions from molecular dynamics
simulations. This body of work forms the basis for a molecular-scale understanding of
reactions taking place at surfaces of geochemically relevant mineral particles. These
reactions are not only limited to ion and solvent exchange but are also extended to
understand particle-particle interactions in the context of oriented aggregation. |