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CPP: Chemische Physik und Polymerphysik

CPP 15: Dynamics and Diffusion

CPP 15.2: Vortrag

Mittwoch, 29. März 2006, 14:15–14:30, ZEU 114

Diffusion processes in binary fluid mixtures in confined geometries. — •Jochen Sommerfeld and Martin Schoen — Stranski-Laboratorium für Physikalische und Theoretische Chemie, Sekretariat C 7, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin

By means of molecular dynamics (MD) simulations we study the dynamical properties of binary fluid mixtures confined by planar substrates. Molecules of fluid mixtures interact through Lennard-Jones(12,6) potentials. Interactions between fluid particles and the wall substrates are described by Lennard-Jones(10,4) potentials. Thus we can explore both symmetric and asymmetric mixtures by choosing the depth of potentials {є_AA,є_BB,є_AB} and energetic preference of one kind of fluids by substrates (i.e., the selectivity of the substrates). We calculate transport coefficients using the Green-Kubo relations (i.e., integrating of time correlation functions). We focus on the calculation of diffusion coefficients, both self-diffusion coefficients D_AA and D_BB and interdiffusion coefficient D_AB, and the self-part of the intermediate scattering function F_s(k,t) depending on the distance between substrates, selectivity of the walls, and the Lennard-Jones parameters of the two kinds of particles. The effect of phase separation on calculated quantities will be analyzed.