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Nascent crystallization of a growing chain on a catalyst surface: a nonequilibrium molecular dynamics simulation
Wei Mao1, Bin Kong, Xiaozhen Yang
1Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
The Journal of Physical Chemistry. B
|May 9, 2008
Summary
This study introduces growing chain molecular dynamics (GCMD) simulations to model polymer crystallization on catalyst surfaces. The research reveals a two-stage crystallization process involving nucleation and crystal growth with distinct stem elongation and folding dynamics.
Area of Science:
- Polymer Science
- Materials Science
- Computational Chemistry
Background:
- Polymer chain aggregation on catalyst surfaces is crucial for material properties.
- Understanding polymerization mechanisms at the molecular level is essential for controlling polymer structure.
Purpose of the Study:
- To investigate polymer chain aggregation behavior during polymerization on a catalyst surface.
- To elucidate the crystallization mechanism of growing polymer chains using a novel simulation method.
Main Methods:
- Development and application of the growing chain molecular dynamics (GCMD) simulation method.
- Nonequilibrium molecular dynamics simulations to capture dynamic aggregation processes.
Main Results:
- Polymer chains crystallize on the catalyst surface in two stages: nucleation and crystal growth.
- Nucleation involves chain absorption, folding into a stable nucleus (3-5 stems) around 100 bonds.
- Crystal growth features alternating stem elongation (constant stems, 5-25 ns) and chain folding (reduced stems, 0.1-0.5 ns).
Conclusions:
- The GCMD method effectively simulates polymer crystallization dynamics.
- A detailed mechanism for polymer crystallization during surface-initiated polymerization is proposed.
- The interplay between stem elongation and chain folding governs the final polymer structure.
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