Influence of Rigidity and Knot Complexity on the Knotting of Confined Polymers

Author(s)
Peter Poier, Christos N. Likos, Richard Matthews
Abstract

We employ computer simulations and thermodynamic integration to analyze the effects of bending rigidity and slit confinement on the free energy cost of tying knots, ΔFknotting, on polymer chains under tension. A tension-dependent, nonzero optimal stiffness κmin exists, for which ΔFknotting is minimal. For a polymer chain with several stiffness domains, each containing a large amount of monomers, the domain with stiffness κmin will be preferred by the knot. A local analysis of the bending in the interior of the knot reveals that local stretching of chains at the braid region is responsible for the fact that the tension-dependent optimal stiffness has a nonzero value. The reduction in ΔFknotting for a chain with optimal stiffness relative to the flexible chain can be enhanced by tuning the slit width of the 2D confinement and increasing the knot complexity. The optimal stiffness itself is independent of the knot types we considered, while confinement shifts it toward lower values.

Organisation(s)
Computational and Soft Matter Physics
Journal
Macromolecules
Volume
47
Pages
3394-3400
No. of pages
7
ISSN
0024-9297
DOI
https://doi.org/10.1021/ma5006414
Publication date
05-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
103023 Polymer physics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/9cdac365-dd40-4020-a50c-3c3c868423fd