Brownian cluster dynamics with short range patchy interactions: its application to polymers and step-growth...

Area of Science:

• Soft Matter Physics
• Polymer Science
• Computational Chemistry

Background:

• Colloidal aggregation studies typically focus on isotropic interactions.
• Simulating complex polymer behavior, especially far from equilibrium, remains challenging.

Purpose of the Study:

• To introduce a novel simulation technique based on Brownian cluster dynamics for patchy particle systems.
• To investigate the influence of solvent quality on step-growth polymerization and resulting network structures.

Main Methods:

• Developed a simulation technique implementing the Kern-Frenkel potential for patchy interactions.
• Modeled particle thermal motion with random translations and rotations.
• Simulated step-growth polymerization using irreversible patch aggregation and isotropic square-well potentials to mimic solvent quality.

Main Results:

• The algorithm accurately reproduces static and dynamic properties of single polymer chains.
• Under poor solvent conditions, a competition between phase separation and polymerization was observed.
• A unique, kinetically trapped, arrested network structure composed of strands and nodes was discovered.

Conclusions:

• The new simulation technique provides access to system dynamics and kinetics, even far from equilibrium.
• The discovered arrested network structure offers insights into the mechanisms of stranded gel formation.
• The method allows tuning local chain flexibility by adjusting patch angles.