Berlin 2001 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 16: Poster: Dynamics of Molecular Systems, Polymer Dynamics, Glass Transition, Crystallization, Electronic Properties of Polymers

CPP 16.4: Poster

Montag, 2. April 2001, 12:30–15:00, AT1

Screening of Hydrodynamic Interactions in Semidilute Polymer Solutions: A Computer Simulation Study — •Burkhard Dünweg, Patrick Ahlrichs, and Ralf Everaers — Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz

We study single-chain motion in semidilute solutions of polymers of length N = 1000 with excluded-volume and hydrodynamic interactions by a novel algorithm. The method is based upon a simple frictional coupling between a stochastic lattice Boltzmann scheme, which models the solvent hydrodynamics, and a continuum bead-spring model simulated by stochastic dynamics. The crossover length of the transition from Zimm (short lengths and times) to Rouse dynamics (larger scales) is proportional to the static screening length. The crossover time is the corresponding Zimm time. Our data indicate Zimm behavior at large lengths but short times. There is no hydrodynamic screening until the chains feel constraints, after which they resist the flow: “Incomplete screening” occurs in the time domain.