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Aggregation of flexible polyelectrolytes: Phase diagram and dynamics
Anvy Moly Tom1, R Rajesh1, Satyavani Vemparala1
1The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India.
The Journal of Chemical Physics
|October 17, 2017
Summary
Flexible charged polymers form distinct aggregated structures with trivalent counterions. Backbone flexibility significantly impacts aggregation dynamics and phase behavior, unlike rigid polyelectrolytes.
Area of Science:
- Polymer Science
- Soft Matter Physics
- Computational Chemistry
Background:
- Similarly charged polymers (polyelectrolytes) aggregate with oppositely charged counterions.
- Understanding aggregation is key for biological processes involving DNA and proteins.
Purpose of the Study:
- To determine the phase diagram of flexible charged polymers with trivalent counterions.
- To characterize aggregate morphology and aggregation dynamics.
- To investigate the role of backbone flexibility and charge density.
Main Methods:
- Large-scale coarse-grained molecular dynamics simulations.
- Phase diagram determination.
- Morphological and dynamic characterization of aggregates.
Main Results:
- Three distinct phases observed: no aggregation, finite bundle phase, and fully phase separated.
- Polymer backbone flexibility induces entanglement, introducing new time scales.
- Aggregation dynamics slow down, with the decay exponent depending on charge density.
Conclusions:
- Backbone flexibility significantly alters polyelectrolyte aggregation compared to rigid systems.
- Entanglement due to flexibility introduces complex dynamics and phase behavior.
- Results highlight the critical role of polymer architecture in self-assembly.
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