Paper Number
PO35
Session
Poster Session
Title
Untying of complex knots on stretched polymers in elongational fields
Presentation Date and Time
October 17, 2018 (Wednesday) 6:30
Track / Room
Poster Session / Woodway II/III
Authors
- Soh, Beatrice W. (Massachusetts Institute of Technology, Chemical Engineering)
- Klotz, Alexander R. (Massachusetts Institute of Technology)
- Doyle, Patrick S. (Massachusetts Institute of Technology, Department of Chemical Engineering)
Author and Affiliation Lines
Beatrice W. Soh, Alexander R. Klotz, and Patrick S. Doyle
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142
Speaker / Presenter
Soh, Beatrice W.
Text of Abstract
Knotting is a prevalent phenomenon which occurs in long polymer chains. We perform Brownian dynamics simulations and single-molecule DNA experiments to investigate knot untying in elongational fields that is induced by the knot being convected off the chain. The change in knot size as the knot moves off the chain and unties causes a change in the effective Weissenberg number, which in turn leads to a change in chain extension. Large scale chain conformational changes are observed in both simulations and experiments for complex knots at low Wi. We investigate the knot untying time and untying-induced change in extension for a range of knot types and field strengths. The change in extension due to knot untying is found to scale quadratically with initial knot size for Wi > 1.5. Due to the changes in chain extension as a knot unties, the untying process can be diffusion- or convection-driven.