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Morphology dictated heterogeneous dynamics in two-dimensional aggregates
Tamoghna Das1, T Lookman2, M M Bandi3
1Collective Interactions Unit, OIST Graduate University, Onna, Okinawa 9040495, Japan. tamoghna.das@nist.gov.
Soft Matter
|November 19, 2016
Summary
Particle aggregate structures vary widely due to competing forces. Microscopic mechanisms, like symmetric caging versus asymmetric binding, dictate morphology and influence particle dynamics and diffusivity.
Area of Science:
- Soft Matter Physics
- Materials Science
- Statistical Mechanics
Background:
- Particulate aggregates exhibit diverse morphologies, from compact to string-like, driven by inter-particle forces.
- Understanding the link between aggregate structure and dynamics is crucial for materials design.
Purpose of the Study:
- To identify microscopic mechanisms governing different particulate aggregate morphologies.
- To investigate the relationship between aggregate microstructure and particle dynamics.
Main Methods:
- Simulating particle trajectories in two dimensions at fixed density and temperature.
- Analyzing particle binding and neighbor interactions.
- Measuring time-dependent diffusivity and structural randomness.
Main Results:
- Symmetric caging leads to compact clusters; asymmetric binding forms non-compact aggregates.
- Distinct timescales characterize these microscopic mechanisms.
- Diffusivity varies with morphology and is generally sub-diffusive at low temperatures.
Conclusions:
- Microstructure and dynamics of particulate aggregates are intrinsically linked.
- A generic relation between diffusivity and structural randomness holds for these complex systems.
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