Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 21: POSTER: Dynamics and Diffusion
CPP 21.5: Poster
Mittwoch, 28. März 2007, 16:00–18:30, Poster B
Dielectric response of polar liquids in narrow slit pores — Vladimir Froltsov1 and •Sabine Klapp1,2 — 1Stranski-Laboratorium, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin — 2Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin
Based on molecular dynamics (MD) simulations and a simple (Stockmayer) model we investigate
the static and dynamic dielectric response of polar liquids confined to narrow slit pores.
The MD simulations are used to calculate the time–dependent
polarization fluctuations along directions parallel and perpendicular to the walls,
from which the components of the frequency–dependent dielectric tensor can be
derived via linear response theory. Our numerical results reveal that the system’s response
is strongly anisotropic. The parallel dielectric function, є∥(ω),
has Debye–like character very similar to the corresponding
isotropic bulk function, єbulk(ω),
at the same chemical potential.
Indeed, the main confinement
effect on є∥(ω) consists in a shift towards smaller values relative
to the bulk function. On the other hand, in perpendicular direction
we observe a characteristic peak in the absorption part of the dielectric function,
є⊥(ω). This
peak is absent in the bulk system and reflects
strongly pronounced, damped oscillations in the polarization fluctuations
normal to the walls.
V. A. Froltsov and S. H. L. Klapp, J. Chem. Phys. 124, 134701 (2006).
V. A. Froltsov and S. H. L. Klapp, submitted