8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Wed 711:10-14:00P5.15Collective dynamics of colloids at fluid interfacesJohannes Bleibel 11 MPI for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, GermanyUsing Brownian dynamics simulations, we study the structure formation of a distribution ofmicrometer-sized colloidal particles trapped at a fluid interface under the action of their mutualcapillary attraction. The distance dependence of the attraction exhibits a crossover at a separationl (capillary length, typically in the mm range) from a logarithmic decay (formally analogous totwo-dimensional gravity) to an exponential decay. The initial growth of fluctuations as seen in thesimulations is very well captured by a linear stability analysis within a mean field picture. Furtherevolution is monitored by means of quantifiers (Minkowski functionals) which are particularlysensitive to the formation of highly inhomogeneous structures. As the parameter l is increased,the time dependence of structure formation shows good scaling with the Jeans time which governsthe time dependence in a system undergoing self-gravitational collapse. Also the cold collapsescenario known from gravitational systems remains valid as long l is larger than the system size.Finally, the influence of hydrodynamic interactions on the structure formation is studied.15