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BP: Fachverband Biologische Physik

BP 6: Statistical Physics of Biological Systems II (joint DY, BP)

BP 6.11: Talk

Monday, March 14, 2011, 16:45–17:00, HÜL 186

Thermally activated fragmentation of a homopolymer chain — •Simon Fugmann and Igor M. Sokolov — Humboldt-Universität zu Berlin, Department of Physics, Newtonstrasse 15, 12489 Berlin

We consider the thermally activated fragmentation of a homopolymer chain, which can exhibit strongly non-Markovian behavior on the timescale of interest. In our model the dynamics of the intact chain is a Rouse one until a bond breaks and bond breakdown is considered as a first passage problem over a barrier to an absorbing boundary. Using the framework of the Wilemski-Fixman approximation we calculate activation times of individual bonds for free and grafted polymer chains. We show that these times crucially depend on the length of the chain and the location of the bond yielding a minimum at the free chain ends. Going beyond the Wilemski-Fixman approximation we show that a generalized form of the renewal equation for barrier crossings serves to improve the quantitative agreement between numerical simulations and analytical predictions.