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Modeling a tethered polymer in Poiseuille flow
1Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
The Journal of Chemical Physics
|June 11, 2005
Summary
We studied tethered polymers in flow, observing shape changes from sphere to rod as velocity increased. Backflow effects from polymer end fluctuations significantly boosted fluid viscosity.
Area of Science:
- Polymer physics
- Fluid dynamics
- Computational science
Background:
- Tethered polymers exhibit complex behaviors in fluid flow.
- Understanding these behaviors is crucial for applications in microfluidics and biomaterials.
- Previous studies have explored polymer dynamics, but multiscale simulations offer new insights.
Purpose of the Study:
- To investigate the morphological transitions of a tethered polymer in Poiseuille flow.
- To analyze the relationship between polymer extension and flow velocity.
- To identify the causes of increased effective viscosity due to backflow effects.
Main Methods:
- Utilized a multiscale algorithm coupling molecular dynamics for the polymer and the stochastic rotation algorithm for the solvent.
- Simulated a particle-based Navier-Stokes integrator to model fluid behavior.
- Analyzed polymer morphology and extension as a function of flow velocity.
Main Results:
- Successfully reproduced the series of polymer morphological transitions: sphere, distorted sphere, trumpet, stem, and flower to rod.
- Demonstrated that polymer extension is dependent on flow velocity.
- Identified polymer end fluctuations as the primary cause of increased effective viscosity due to backflow.
Conclusions:
- The multiscale approach accurately captures polymer behavior in Poiseuille flow.
- Polymer extension and morphological changes are directly influenced by flow velocity.
- Backflow effects, driven by polymer end dynamics, significantly impact fluid viscosity.
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