Polymer dynamics

Single tethered polymer under shear flow: cyclic dynamics

The cicle of a tether under shear flow

watch the movie here
The long-time dynamics of a single end-tethered chain under shear flow are studied using molecular and Brownian dynamics simulations of a flexible polymer. As observed in previous experiments with tethered DNA [Phys. Rev. Lett. 84, 4769 (2000)], under a flow sheared at constant rate the chain performs a cyclic motion. But contrary to what it has been previously suggested, a well defined characteristic period exists and, it is clearly revealed in the cross-spectra of the chain extension along flow and gradient directions. The main cycling time scales like the convective time needed by the flow to stretch the polymer, being about ten times the longest relaxation time of the chain in flow. This coherent recursive motion introduces long memory in the fluid and suggests resonance effects under periodic external forcing.

R. Delgado-Buscalioni, Cyclic dynamics of a tethered polymer under shear flow, Phys. Rev. Lett. 96, 088303 (2006)


Free polymers under shear flow

Papers

  • R. Delgado-Buscalioni, Cyclic dynamics of a tethered polymer under shear flow, Phys. Rev. Lett. 96, 088303 (2006)
  • R. Delgado-Buscalioni, Dynamics of a single polymer under shear flow, AIP Conf. Proceedings, 913,114 (2007)
  • S. Barsky, R. Delgado-Buscalioni and P.V. Coveney, Comparison of molecular dynamics to hybrid molecular dynamics-computational fluid dynamics for a single tethered polymer in solution, J. Chem. Phys. 121 2403 (2004)
  • R. Delgado-Buscalioni and P. V. Coveney Structure of a tethered polymer under flow using molecular dynamics and hybrid molecular-continuum simulations, Physica A , 362 (1), 30-35 (2006)

    • Some talks and seminars

  • Dynamics of a polymer under shear flow