Berlin 2008 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 1: Critical phenomena and phase transitions

DY 1.6: Vortrag

Montag, 25. Februar 2008, 11:30–11:45, MA 004

Molecular Dynamics simulations of the phase separation of polymer solutions in thin film geometry — •Katarzyna Bucior, Leonid Yelash, and Kurt Binder — Institute of Physics, Johannes-Gutenberg University of Mainz, Mainz, Germany

We use a coarse-grained model of hexadecane dissolved in supercritical carbon dioxide to simulate the phase separation, initiated by quenching a system into an unstable region of the phase diagram, e.g. by temperature or pressure jumps. The parameters of the model are fitted to reproduce critical parameters of hexadecane and carbon dioxide. The study is performed in slit like pores, formed by two infinite parallel walls consisting of spherical particles.

We present the typical results for the observed time evolutions during phase separation for this model, structure factors, snapshot pictures, density profiles, density distributions. Since the behavior of the system depends on the distance from the wall, we calculate some properties in layers parallel to the walls. The time dependence of the characteristic domain size is also discussed.