Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 12: POSTER Colloids, Nanoparticles and Self-Organizing Systems
CPP 12.22: Poster
Dienstag, 28. März 2006, 17:00–19:00, P3
Structure and dynamics of confined charged colloids — •Madeleine Kittner1 and PD Dr. rer. nat. Sabine Klapp1,2 — 1TU Berlin, Theoretische Chemie - Stranski-Lab, Strasse des 17.Juni 135, 10623 Berlin — 2TU Berlin, Theoretische Physik, Hardenbergstr. 36, 10623 Berlin
We investigate the structure and dynamics of charged colloids confined by two plane-parallel repulsive walls (slit pore), using Molecular Dynamics Simulations (MD) in a canonical ensemble. The colloidal system is described by a purely repulsive soft-sphere-Yukawa potential, that involves only the screened spherical macromolecules. The range of repulsion is controlled by the Yukawa parameter κ which, in real systems, is determined by the ionic strength or the charge density.
Our MD results show that an increase of the repulsion range (i.e., decrease of κ) yields an increase of the components of the pressure tensor, particularly in the direction normal to the walls. This is consistend with the behavior of the density profiles, which are highly structured for small κ especially in narrow pores. On the other hand, considering the translational dynamics parallel to the walls, we observe that decrease of the range of repulsion leads to decreasing pore-averaged diffusion constants.We also investigate the inhomogeneity of the dynamics induced by the layer formation.