Europhys. Lett.
Volume 71, Number 2, July 2005
Page(s) 221 - 227
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 24 June 2005
Europhys. Lett., 71 (2), pp. 221-227 (2005)
DOI: 10.1209/epl/i2005-10087-1

Single-polymer dynamics: Coil-stretch transition in a random flow

S. Gerashchenko, C. Chevallard and V. Steinberg

Department of Physics of Complex Systems, Weizmann Institute of Science Rehovot, 76100 Israel

received 17 March 2005; accepted in final form 26 May 2005
published online 24 June 2005

By quantitative studies of statistics of polymer stretching in an elastic turbulence and the statistical properties of this random flow itself that are characterized by the average Lyapunov exponents of particle pair separations, $\bar{\lambda}$, we demonstrate that the stretching of polymer molecules in a 3D random flow occurs rather sharply via the coil-stretch transition. The experimental value of the onset of the coil-stretch transition, $\bar{\lambda}_{cr}\cdot\tau=0.77\pm 0.20$, where $\tau$ is the polymer relaxation time, is found to be rather close to the theoretically predicted one.

47.50.+d - Non-Newtonian fluid flows.
83.50.-v - Deformation and flow.
87.15.He - Dynamics and conformational changes.

© EDP Sciences 2005