Spatially resolved fast dynamics reveal the aggregation mechanism in two-dimensions

Area of Science:

• Soft Matter Physics
• Materials Science
• Statistical Mechanics

Background:

• Two-dimensional aggregates exhibit diverse morphologies, including compact crystalline clusters and non-compact string-like conformations.
• Understanding particle dynamics within these aggregates is crucial for their function.

Purpose of the Study:

• To analyze simulated trajectories of compact and non-compact two-dimensional aggregates.
• To identify differences in short-time pre-caging mechanisms based on aggregate morphology.

Main Methods:

• Simulated trajectory analysis of two-dimensional aggregates with fine spatial resolution.
• Examination of self-overlap statistics to differentiate short-time dynamics.

Main Results:

• Long-time aggregate geometry is statistically similar for both compact and non-compact forms.
• Distinct short-time pre-caging mechanisms were identified.
• Compact aggregates show a direct length-time proportionality for particle localization, while non-compact clusters exhibit a non-monotonic relationship.

Conclusions:

• Short-time particle localization dynamics differ significantly between compact and non-compact aggregates.
• The relationship between length and time scales in particle localization may explain structure-function relationships in soft materials.