Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 32: Polymer Physics III

CPP 32.3: Vortrag

Donnerstag, 26. März 2009, 10:00–10:15, ZEU 222

Traveling spatially periodic forcing of phase separation — •Vanessa Weith, Alexei Krekhov, and Walter Zimmermann — Theoretische Physik I, Universität Bayreuth, 95440 Bayreuth, Germany

Within the framework of a suitably generalized Cahn-Hilliard model [1,2] we present a theoretical analysis of phase separation of binary polymer mixtures in the presence of spatially periodic forcing of wavenumber q traveling with a velocity v.

We found that for a stationary forcing (v=0) phase separation is locked beyond a critical forcing amplitude a₀(q) to periodic patterns of wavenumber Q=q. This critical amplitude is increased at increasing the pulling velocity v. The bifurcation diagram, the existence range of the periodic solutions, as well as the dynamics of phase separation influenced by the forcing have been studied.

We have also investigated the existence and stability of subharmonic periodic patterns of wavenumber Q=q/m (m≥2) and their spatio-temporal behaviour for the cases v=0 and v≠0. We obtained that the critical forcing amplitudes for the stabilization of subharmonic periodic patterns are larger than for the harmonic solution with Q=q.

[1] A. P. Krekhov and L. Kramer, Phys. Rev. E 70, 061801 (2004)

[2] V. Weith, A. Krekhov and W. Zimmermann, Eur. Phys. J. B, in press (2008)