Beating of grafted chains induced by active Brownian particles

Area of Science:

• Soft Matter Physics
• Statistical Mechanics
• Polymer Physics

Background:

• Active Brownian particles (ABPs) exhibit self-propulsion, leading to unique collective behaviors.
• Polymer brushes, or "hairy" surfaces, present complex environments for interacting particles.

Purpose of the Study:

• To investigate the dynamic interactions between active Brownian particles and a polymer brush.
• To understand how particle activity influences surface morphology and particle distribution.

Main Methods:

• Two-dimensional simulations of active Brownian particles interacting with a polymer brush.
• Analysis of particle accumulation, cluster formation, and chain dynamics.
• Theoretical modeling to explain observed phenomena.

Main Results:

• Increased propelling force enhances inhomogeneous accumulation of ABPs within the brush.
• Dynamic clustering and oscillatory motion (beating) of chain bundles occur at high forces.
• Chains are stretched by effective shear forces from ABPs, reducing average brush thickness.

Conclusions:

• Active Brownian particles induce significant structural changes and dynamic behaviors in polymer brushes.
• The beating phenomenon in single chains is characterized by an oscillatory period dependent on chain length and propelling force.
• Theoretical predictions align well with simulation data, validating the model.