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Monte Carlo simulation of a single ring among linear chains: structural and dynamic heterogeneity
Yong-Biao Yang1, Zhao-Yan Sun, Cui-Liu Fu
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
The Journal of Chemical Physics
|August 17, 2010
Summary
Ring polymer dynamics in linear chains are complex. Threading by linear chains creates topological states that significantly slow ring diffusion, leading to non-ergodic behavior and distinct diffusive segments.
Area of Science:
- Polymer Physics
- Soft Matter Physics
- Computational Materials Science
Background:
- Understanding polymer dynamics in confined environments is crucial for materials science.
- Ring polymers exhibit unique conformational and dynamic properties compared to linear chains.
- The influence of surrounding linear chains on ring polymer behavior is not fully understood.
Purpose of the Study:
- To investigate the conformational and dynamic properties of a single flexible ring polymer within a matrix of linear chains.
- To examine how the degree of polymerization of the linear chains affects ring polymer behavior.
- To elucidate the role of topological interactions in ring polymer diffusion.
Main Methods:
- Lattice Monte Carlo simulations using the bond-fluctuation model.
- Analysis of conformational properties (mean-square radius of gyration, asphericity parameter).
- Investigation of center-of-mass diffusion and primitive path analysis.
Main Results:
- Conformation properties are largely insensitive to linear chain length, but longer chains show increased heterogeneity.
- Ring polymer diffusion significantly slows with increasing linear chain length, exhibiting heterogeneous dynamics.
- Topological threading by linear chains creates distinct states, dramatically impacting ring mobility and leading to non-ergodic behavior.
Conclusions:
- The diffusion of ring polymers in linear chain matrices is segment-based, with distinct conformational states.
- Topological entanglement with linear chains is a key factor governing ring polymer dynamics.
- Non-ergodic behavior arises from long-lived topological conformers, influencing diffusion on relevant timescales.
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