Entangled chain dynamics of polymer knots in extensional flow

Demosthenes Kivotides, S. Louise Wilkin, Theo G. Theofanous

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

We formulate a coarse-grained molecular-dynamics model of polymer chains in solution that includes hydrodynamic interactions, thermal fluctuations, nonlinear elasticity, and topology-preserving solvent mediated excluded volume interactions. The latter involve a combination of potential forces with explicit geometric detection and tracking of chain entanglements. By solving this model with numerical and computational methods, we study the physics of polymer knots in a strong extensional flow (Deborah number De=1.6). We show that knots slow down the stretching of individual polymers by obstructing via entanglements the "natural," unraveling, and flow-induced chain motions. Moreover, the steady-state polymer length and polymer-induced stress values are smaller in knotted chains than in topologically trivial chains. We indicate the molecular processes via which the rate of knot tightening affects the rheology of the solution.
LanguageEnglish
Article number041808
Number of pages16
JournalPhysical Review E
Volume80
Issue number4
DOIs
Publication statusPublished - 29 Oct 2009

Fingerprint

Knot
Polymers
polymers
Entanglement
Hydrodynamic Interaction
Nonlinear Elasticity
Rheology
rheology
Molecular Dynamics
dynamic models
Computational Methods
preserving
Dynamic Model
Trivial
topology
elastic properties
Numerical Methods
hydrodynamics
Physics
interactions

Keywords

  • polymers
  • degrees of freedom (mechanics)
  • elasticity
  • fluid dynamics
  • natural polymers
  • numerical methods
  • chain dynamics
  • chain entanglements
  • chain motions
  • coarse-grained
  • Deborah numbers
  • detection and tracking
  • excluded-volume interactions
  • extensional flows
  • hydrodynamic interaction
  • induced stress
  • molecular process
  • molecular-dynamics model
  • nonlinear elasticity
  • polymer chains
  • polymer length
  • potential forces
  • thermal fluctuations

Cite this

Kivotides, Demosthenes ; Wilkin, S. Louise ; Theofanous, Theo G. / Entangled chain dynamics of polymer knots in extensional flow. In: Physical Review E. 2009 ; Vol. 80, No. 4.
@article{3d43a6f1f1364b2eb58682387318db8e,
title = "Entangled chain dynamics of polymer knots in extensional flow",
abstract = "We formulate a coarse-grained molecular-dynamics model of polymer chains in solution that includes hydrodynamic interactions, thermal fluctuations, nonlinear elasticity, and topology-preserving solvent mediated excluded volume interactions. The latter involve a combination of potential forces with explicit geometric detection and tracking of chain entanglements. By solving this model with numerical and computational methods, we study the physics of polymer knots in a strong extensional flow (Deborah number De=1.6). We show that knots slow down the stretching of individual polymers by obstructing via entanglements the {"}natural,{"} unraveling, and flow-induced chain motions. Moreover, the steady-state polymer length and polymer-induced stress values are smaller in knotted chains than in topologically trivial chains. We indicate the molecular processes via which the rate of knot tightening affects the rheology of the solution.",
keywords = "polymers, degrees of freedom (mechanics), elasticity, fluid dynamics, natural polymers, numerical methods, chain dynamics, chain entanglements, chain motions, coarse-grained, Deborah numbers, detection and tracking, excluded-volume interactions, extensional flows, hydrodynamic interaction, induced stress, molecular process, molecular-dynamics model, nonlinear elasticity, polymer chains, polymer length, potential forces, thermal fluctuations",
author = "Demosthenes Kivotides and Wilkin, {S. Louise} and Theofanous, {Theo G.}",
year = "2009",
month = "10",
day = "29",
doi = "10.1103/PhysRevE.80.041808",
language = "English",
volume = "80",
journal = "Physical Review E",
issn = "1539-3755",
publisher = "American Physical Society",
number = "4",

}

Entangled chain dynamics of polymer knots in extensional flow. / Kivotides, Demosthenes; Wilkin, S. Louise; Theofanous, Theo G.

In: Physical Review E, Vol. 80, No. 4, 041808, 29.10.2009.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Entangled chain dynamics of polymer knots in extensional flow

AU - Kivotides, Demosthenes

AU - Wilkin, S. Louise

AU - Theofanous, Theo G.

PY - 2009/10/29

Y1 - 2009/10/29

N2 - We formulate a coarse-grained molecular-dynamics model of polymer chains in solution that includes hydrodynamic interactions, thermal fluctuations, nonlinear elasticity, and topology-preserving solvent mediated excluded volume interactions. The latter involve a combination of potential forces with explicit geometric detection and tracking of chain entanglements. By solving this model with numerical and computational methods, we study the physics of polymer knots in a strong extensional flow (Deborah number De=1.6). We show that knots slow down the stretching of individual polymers by obstructing via entanglements the "natural," unraveling, and flow-induced chain motions. Moreover, the steady-state polymer length and polymer-induced stress values are smaller in knotted chains than in topologically trivial chains. We indicate the molecular processes via which the rate of knot tightening affects the rheology of the solution.

AB - We formulate a coarse-grained molecular-dynamics model of polymer chains in solution that includes hydrodynamic interactions, thermal fluctuations, nonlinear elasticity, and topology-preserving solvent mediated excluded volume interactions. The latter involve a combination of potential forces with explicit geometric detection and tracking of chain entanglements. By solving this model with numerical and computational methods, we study the physics of polymer knots in a strong extensional flow (Deborah number De=1.6). We show that knots slow down the stretching of individual polymers by obstructing via entanglements the "natural," unraveling, and flow-induced chain motions. Moreover, the steady-state polymer length and polymer-induced stress values are smaller in knotted chains than in topologically trivial chains. We indicate the molecular processes via which the rate of knot tightening affects the rheology of the solution.

KW - polymers

KW - degrees of freedom (mechanics)

KW - elasticity

KW - fluid dynamics

KW - natural polymers

KW - numerical methods

KW - chain dynamics

KW - chain entanglements

KW - chain motions

KW - coarse-grained

KW - Deborah numbers

KW - detection and tracking

KW - excluded-volume interactions

KW - extensional flows

KW - hydrodynamic interaction

KW - induced stress

KW - molecular process

KW - molecular-dynamics model

KW - nonlinear elasticity

KW - polymer chains

KW - polymer length

KW - potential forces

KW - thermal fluctuations

UR - http://www.scopus.com/inward/record.url?scp=70449106453&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.80.041808

DO - 10.1103/PhysRevE.80.041808

M3 - Article

VL - 80

JO - Physical Review E

T2 - Physical Review E

JF - Physical Review E

SN - 1539-3755

IS - 4

M1 - 041808

ER -