COMPUTER-SIMULATION OF KINETICS OF COIL-STRETCHED CHAIN TRANSITION IN ELONGATIONAL FLOW

The Brownian dynamics technique is used to simulate the behavior of a polymer chain in an elongational flow. A macromolecule is represented by dumbbell with conformation-dependent friction coefficient. Equilibrium and kinetic properties of the chain are studied. The effective potential approximation is shown to be quite appropriate for the description of the chain distribution function. The transition times through the effective potential barrier are in a good agreement with the prediction of the Kramers theory. The S-shaped curve for the extension ratio of the dumbbell as a function of the velocity gradient is observed when simulation times are comparable with the transition times.