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 16.12: Poster

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

Cyclization of a polymer with charged reactive end-groups — •Jörg Stampe and Igor M. Sokolov — Universität Freiburg, Theoretische Polymerphysik, Hermann-Herder Strasse 3, D-79104 Freiburg, Germany

We calculate the cyclization rate k(t) of a single polymer chain with charged end groups, where cyclization takes place with probability one when the ends approach each other at a distance smaller than the reaction radius R. Using Monte-Carlo simulations within a kink-jump model we show that the long-time asymptotic value of k for longer chains and attractive Coulomb interaction does not depend on R, but depends strongly on the Onsager radius, characterizing the strength of electrostatic interaction. This result relies only on the large-scale behavior of the chain and is reproduced within a simple harmonic-spring approximation. The harmonic-spring model leads to a diffusion equation which is solved numerically. The solution for long chains is confirmed within analytical approximations.

to appear in the Journal of Chemical Physics