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Internal friction and mode relaxation in a simple chain model
1Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany. simon.fugmann@physik.hu-berlin.de
The Journal of Chemical Physics
|December 23, 2009
Summary
This study reveals that nonlinear polymer chain interactions, particularly double-well potentials modeling internal friction, significantly alter relaxation dynamics. These effects, including increased relaxation times and subdiffusive scaling, mimic complex polymer systems.
Area of Science:
- Polymer Physics
- Statistical Mechanics
- Condensed Matter Theory
Background:
- Understanding polymer chain dynamics is crucial for materials science.
- The Rouse chain model provides a baseline for polymer relaxation but often simplifies interactions.
- Nonlinear interactions and internal friction are key factors in real polymer behavior.
Purpose of the Study:
- To investigate equilibrium relaxation properties of a 1D polymer model with nonlinear bead interactions.
- To compare relaxation dynamics for single-well and double-well potentials.
- To explore how minimal models can capture complex polymer relaxation phenomena.
Main Methods:
- Simulation of a one-dimensional polymer chain model.
- Analysis of equilibrium relaxation properties, including end-to-end distance and principal component dynamics.
- Comparison with Rouse chain and harmonic chain models.
Main Results:
- Single-well potentials yield relaxation similar to Rouse chains.
- Double-well potentials (modeling internal friction) show vastly different relaxation at intermediate times/temperatures.
- Principal components exhibit larger relaxation times and subdiffusive scaling, irrespective of potential type.
Conclusions:
- Nonlinear interactions, especially those mimicking internal friction, dramatically impact polymer relaxation.
- A minimal 1D model can effectively replicate complex relaxation behaviors observed in larger systems.
- The findings highlight the importance of internal friction in determining polymer dynamics and relaxation times.
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