Dynamical Slowdown of Polymers in Laminar and Random Flows

Antonio Celani (1) , Alberto Puliafito (1) , Dario Vincenzi (2, 3, 4)

1 INLN - Institut Non Linéaire de Nice Sophia-Antipolis
2 Department of Fluid Dynamics, Pattern Formation and Nanobiocomplexity
3 MAE - Sibley School of Mechanical and Aerospace Engineering
4 LASSP - Laboratory of Atomic and Solid State Physics [Ithaca]

The influence of an external flow on the relaxation dynamics of a single polymer is investigated theoretically and numerically. We show that a pronounced dynamical slowdown occurs in the vicinity of the coil-stretch transition, especially when the dependence on polymer conformation of the drag is accounted for. For the elongational flow, relaxation times are exceedingly larger than the Zimm relaxation time, resulting in the observation of conformation hysteresis. For random smooth flows hysteresis is not present. Yet, relaxation dynamics is significantly slowed down because of the large variety of accessible polymer configurations. The implications of these results for the modeling of dilute polymer solutions in turbulent flows are addressed.

Mots clés: Single polymer dynamics; Coil-stretch transition; Hydrodynamic interactions

Domaines: Dynamique Chaotique [nlin.CD]; Matière Molle [cond-mat.soft]

Antonio Celani, Alberto Puliafito, Dario Vincenzi. Dynamical Slowdown of Polymers in Laminar and Random Flows. Physical Review Letters, 2006, 97, pp.118301. ⟨10.1103/PhysRevLett.97.118301⟩. ⟨hal-00097741⟩