| Fri April 11th 2008 15:00 | Seminar | Simulation of driven suspensions Rudolf Weeber |
Details:Many dynamic properties of suspensions are not yet understood. Especially, many details of polymer suspensions are not easily accessible experimentally.By introducing a colloidal particle as probe and controlling it using an optical tweezer, some local properties can be examined even outside of equilibrium. Optical tweezers are important tools in the study of colloidal suspensions as well as colloid-polymer mixtures outside of equilibrium, because they make it possible to perturb the system in a controlled manner. In my talk, I will present simulations of a colloidal particle dragged through a polymer suspension and - if time permits - trough a colloidal crystal using an optical tweezer modeled as a moving parabolic potential. From the behavior of the dragged particle within the trap and the surrounding suspension, dynamical properties like drag forces and the rearrangement of surrounding particles in the suspension are obtained. The simulations are compared to experiments and in the case of the polymer suspension to dynamic density functional theory calculations. While most of the simulations have been performed using an improved Brownian dynamics method, the feasability of such simulations with full hydrodynamics using stochastric rotation dynamics will also be treated. | ||
