Activated diffusiophoresis

Area of Science:

• Physics
• Physical Chemistry
• Soft Matter Physics

Background:

• Fluid dynamics and non-equilibrium systems can induce particle motion.
• Diffusiophoresis describes particle movement driven by solute gradients.
• Local, time-dependent fluid perturbations are key to novel phenomena.

Purpose of the Study:

• To investigate diffusiophoretic phenomena arising from local fluid perturbations.
• To analyze particle motion and work extraction in activated fluids.
• To explore controlled particle conveyance using time-dependent fluid profiles.

Main Methods:

• Analytical treatment of conserved fluid density.
• Study of diffusive perturbation propagation.
• Analysis within a two-parallel-wall confinement geometry.

Main Results:

• Demonstration of large-distance diffusiophoretic effects from local activations.
• Investigation into extracting work from inclusions moving in activated fluids.
• Establishment of controlled, stable particle trajectories using time-dependent density profiles.
• Inability to stabilize particle positions in steady-state density profiles.

Conclusions:

• Local fluid activations can induce controllable diffusiophoresis.
• Time-dependent density profiles offer stable particle manipulation, distinct from thermophoresis.
• Findings have broad applicability in experimental soft matter and tracer particle systems.