IWNET

2006

4th International workshop on nonequilibrium thermodynamics and complex fluids
3-7 september 2006, Rhodes, Greece

Home
Scope
Location
Speakers
Program
Abstracts
Author index
Organizing Committee
Scientific Committee
Venue & Accomodation
Registration
News
Contact


ORAL PRESENTATION
Session: 3 Non-equilibrium thermodynamics and Molecular Dynamics
(scheduled: Monday, 15:15 )

Flow and Motion of Polymer Droplets on Polymer Brushes

M. Müller1, C. Pastorino2, K. Binder2
1 Institut für Theoretische Physik, Georg-August Universität, D37077 Göttingen, Germany
2 Institut für Physik, WA331, Johannes Gutenberg Universität, D55099 Mainz, Germany

Polymer brushes are soft, elastically deformable substrates giving rise to a rich wetting behavior and additional molecular dissipation mechanisms for the motion of droplets. We study thin polymer films and droplets on flat brush-covered substrates by non-equilibrium molecular dynamics simulation of a coarse-grained bead-spring model. The brush consists of identical polymers as the droplets. Upon increasing the grafting density the free polymers are expelled from the brush and a brush-melt interface gradually builds up. Molecular conformations and the overlap between brush and melt are studied in equilibrium and under shear. The velocity profile across a thin polymer film is investigated. The slip length adopts large positive values (perfect slip) for low grafting densities, but decreases and becomes negative for densely grafted, autophobic brushes. At high grafting density the polymer melt dewets from the brush and forms droplets. Nanoscopic polymer droplets driven by volume forces are investigated in their steady state. © IWNET 2006

© and Kleanthi for IWNET 2006