Visible Light Actuated Efficient Exclusion Between Plasmonic Ag/AgCl Micromotors and Passive Beads

Area of Science:

• Physical Chemistry
• Materials Science
• Nanotechnology

Background:

• Plasmonic Janus particles are engineered nanomaterials with distinct properties on each side.
• Visible-light photocatalysis enables self-propulsion in Janus particles.
• Understanding the collective behavior of active and passive particles is crucial for micro-device applications.

Purpose of the Study:

• To investigate the collective behavior and interactions of visible-light-driven Ag/AgCl Janus particles with passive polystyrene (PS) beads.
• To analyze how the diffusivity of active Janus particles and their clusters influences passive bead movement.
• To explore the potential of this system for light-controlled transport and chemical sensing.

Main Methods:

• Experimental observation of active diffusion of single Janus particles and their clusters.
• Molecular-Dynamics simulations solving Langevin equations of motion.
• Incorporation of inter-particle interactions: elastic, short-range attraction, and light-induced repulsion.

Main Results:

• The diffusivity of active Janus particles is tunable by controlling the cluster size (2-3 particles for small, >10 for large).
• Janus particle cluster size directly impacts the motion and interaction with passive PS beads.
• Simulations accurately model the complex interplay between active micromotors and passive components.

Conclusions:

• The collective behavior of light-driven Janus particles and passive beads is controllable via particle clustering.
• This system demonstrates potential for applications in light-controlled micro-propulsion and chemical sensing.
• The study provides fundamental insights into active-passive particle interactions in complex fluidic systems.