Non-monotonic dependence of the polymer rupture force on molecule chain lengthS. Fugmann and I. M. Sokolov
Institut für Physik, Humboldt-Universität zu Berlin - Newtonstraße 15, D-12489 Berlin, Germany, EU
received 24 February 2009; accepted in final form 23 March 2009; published April 2009
published online 16 April 2009
We consider the rupture dynamics of a homopolymer chain pulled at one end at a constant loading rate. Our model of the breakable polymer is related to the Rouse chain, with the only difference that the interaction between the monomers is described by the Morse potential instead of the harmonic one, and thus allows for mechanical failure. We show that in the experimentally relevant domain of parameters the dependence of the most probable rupture force on the chain length may be non-monotonic, so that the medium-length chains break easier than the short and the long ones. The qualitative theory of the effect is presented.
82.37.-j - Single molecule kinetics.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
© EPLA 2009