Berlin 2015 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 9: Brownian Motion and Transport (Joint session DY/ CPP/ TT)
DY 9.10: Talk
Monday, March 16, 2015, 17:45–18:00, BH-N 243
Surface interactions of active Janus particles on a hexagonal close-packed colloidal crystal surface — •Udit Choudhury1, John G. Gibbs1,2, and Peer Fischer1,3 — 1Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany — 2Dept. of Physics & Astronomy, Northern Arizona University, Flagstaff, AZ 86011, USA — 3Institute for Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
Autonomous, self-driven colloidal particles are being given greater attention in recent years due to the interesting dynamics associated with out-of-equilibrium systems. Although particle-particle interactions of active colloids, e.g. self-assembly and clustering, are beginning to be regularly studied, particle-surface interactions are less well investigated. Herein, we empirically study the surface interactions of spherical Janus-particles half-coated with Pt in the presence of hydrogen peroxide. The surface consists of close-packed 2D monolayer of hard spheres (beads). This non-planar surface thus corresponds to a periodic potential akin to a fcc (111) lattice face. In this way, the system is an analogue of surface diffusion of adatoms that possess kinetic energy. We find that as the concentration of hydrogen peroxide is increased, the effective translational diffusion also increases which is comparable to enhanced diffusion of adatoms on surfaces at higher temperatures. Rotational diffusion dictates fluctuations in the orientation of the driven bead that lead to jumps form one potential well to its nearest neighbor.