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Semiflexible macromolecules in quasi-one-dimensional confinement: Discrete versus continuous bond angles
Aiqun Huang1, Hsiao-Ping Hsu2, Aniket Bhattacharya1
1Department of Physics, University of Central Florida, Orlando, Florida 32816-2385, USA.
The Journal of Chemical Physics
|January 3, 2016
Summary
Computer simulations reveal distinct behaviors of semiflexible polymers in confined spaces. While continuum and lattice models show similar bulk properties, confinement reveals differences in persistence length and monomer density near walls.
Area of Science:
- Polymer Physics
- Computational Materials Science
- Statistical Mechanics
Background:
- Semiflexible polymers exhibit complex conformations influenced by chain stiffness.
- Understanding polymer behavior in confined geometries is crucial for materials science and nanotechnology.
- Existing models often simplify local chain conformations, necessitating comparative studies.
Purpose of the Study:
- To investigate the conformations of semiflexible polymers confined in a two-dimensional strip using computer simulations.
- To compare the behavior of continuum (bead-spring) and lattice (self-avoiding walk) models under confinement.
- To analyze the effects of confinement on polymer dimensions, density profiles, and persistence length.
Main Methods:
- Molecular dynamics simulations for a continuum bead-spring polymer model with a bond angle potential.
- Monte Carlo simulations for a lattice self-avoiding walk model with discrete bond angles.
- Analysis of average chain dimensions, transverse fluctuations, monomer density, and persistence length.
Main Results:
- Both models exhibit similar bulk crossover from rod-like to self-avoiding walk behavior.
- Under confinement, the lattice model shows renormalized persistence length, unlike the continuum model.
- Monomer density near walls differs: power law for continuum, constant for lattice, while chain end density is constant for both.
- Hairpin conformations appear when persistence length is comparable to confinement width.
Conclusions:
- Confinement significantly alters polymer behavior, revealing model-specific differences not apparent in bulk simulations.
- The choice of model (continuum vs. lattice) impacts predictions for persistence length and wall interactions.
- The study provides insights into polymer conformational transitions under quasi-one-dimensional confinement, bridging flexible and rigid polymer regimes.
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