Structure and dynamics of colloidal particles on incommensurate substrates

The behavior of colloidal particles on substrates is important for a lot of applications in colloidal physics like photonic crystals, colloidal nanofilms, or novel materials with special rheological, frictional, or lubrication properties. Furthermore, colloids on substrates are perfectly suitable as a model system to study complex processes that occur for particles close to structured surfaces in general. In this project, we want to focus on the influence of substrates whose symmetry is incommensurate to the intrinsic symmetry of a colloidal crystal in bulk. Close to such substrates, interesting colloidal phases occur due to the competition between the inter-particle interaction that favors the bulk order and the interaction with the substrate that tries to induce an incommensurate structure. Furthermore, our goal is to better understand the fundamental properties concerning the growth processes of crystalline and quasicrystalline structures. We also expect to observe new dynamical phenomena. For example, time-dependent substrates or drag forces will be used to study colloidal non-equilibrium dynamics. Finally, we want to learn more about external influences on the jamming or glass transition by exploring the slowdown of the dynamics for dense colloidal systems close to a wall with random or at least incommensurate trapping sites.