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Updated: Jan 22, 2026
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Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
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New Insight into Cluster Aggregation Mechanism during Polymerization-Induced Self-Assembly by Molecular Dynamics
Fabrice Brunel1, Jennifer Lesage de la Haye2, Muriel Lansalot1
1Univ Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, C2P2 , 43 Bvd. du 11 Novembre 1918 , F-69616 Villeurbanne , France.
The Journal of Physical Chemistry. B
|July 10, 2019
Summary
Molecular dynamics simulations reveal how copolymer aggregate interactions control self-assembly morphology in emulsion. Repulsive barrier strength dictates aggregation kinetics, influencing final nanostructure formation like vesicles and tubes.
Area of Science:
- Polymer science
- Materials science
- Computational chemistry
Background:
- Polymerization-induced self-assembly (PISA) in emulsion is a key method for creating nanostructures.
- Understanding the kinetics and thermodynamics of PISA is crucial for controlling morphology.
Purpose of the Study:
- To investigate the interaction free energy between self-assembled copolymer aggregates in emulsion using molecular dynamics.
- To elucidate the mechanism by which polymer architecture influences PISA morphology.
Main Methods:
- Molecular dynamics simulations were employed.
- Umbrella sampling and the weighted histogram analysis method (WHAM) were used to calculate interaction free energies.
Main Results:
- An attractive interaction between copolymer micelles was observed at 80 °C with poly(ethylene glycol) (PEG) side chains.
- A repulsive barrier, dependent on PEG side chain position, was identified, influencing aggregation kinetics.
- Strong repulsive barriers led to reaction-limited cluster aggregation (RLCA) and larger vesicles, while weak barriers resulted in diffusion-limited cluster aggregation (DLCA), forming tubular nanostructures and smaller vesicles.
Conclusions:
- The strength of the repulsive barrier is a critical factor controlling PISA kinetics and resulting nanostructure morphology.
- This study provides a mechanistic understanding for morphology transitions (spheres to fibers and vesicles) based on polymer architecture in emulsion PISA.
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