Activity affects the stability, deformation and breakage dynamics of colloidal architectures

Area of Science:

• Soft Matter Physics
• Non-equilibrium Systems
• Colloidal Science

Background:

• Living network architectures require continuous energy input, leading to complex non-equilibrium physics.
• Understanding these systems necessitates controlled experimental models for basic insights.
• Activated self-assembled colloidal architectures offer a tunable platform for studying non-equilibrium dynamics.

Purpose of the Study:

• To numerically investigate the impact of self-propelled colloids on self-assembling colloidal architectures.
• To analyze the breakage dynamics of archetypal substructures (dimers, chains, rings) under active particle influence.
• To understand how particle activity affects structural stability and fragmentation mechanisms.

Main Methods:

• Numerical simulation of active Brownian particles interacting with self-assembling dipatch and tripatch colloidal particles.
• Utilizing a critical Casimir force model for accurate reproduction of colloidal self-assembly.
• Analyzing breakage dynamics by separating the process into potential well escape and particle separation stages.

Main Results:

• Active particles exhibit a rich response, altering the stability of colloidal architectures (enhancing or reducing it).
• Self-propelled particles induce deformation in intact structures and modify fragmentation mechanisms.
• Breakage rates and mechanisms are dependent on the magnitude and direction of the active force.

Conclusions:

• The study provides insights into the non-equilibrium physics of active colloidal systems.
• Findings rationalize the complex interplay between particle activity and structural stability/breakage.
• This work lays the foundation for exploring more intricate active self-assembled architectures.