Fluctuating chemohydrodynamics and the stochastic motion of self-diffusiophoretic particles

Area of Science:

• Physics, Physical Chemistry
• Soft Matter Physics
• Chemical Engineering

Background:

• Self-diffusiophoresis drives active particle motion through surface catalytic reactions.
• Particle motion is stochastic due to thermal and molecular fluctuations.
• Mechanochemical coupling links fluid velocity with reactant/product concentration fields.

Purpose of the Study:

• To develop a thermodynamically consistent theoretical framework for active particle dynamics.
• To model the stochastic translation, rotation, and reaction of active particles.
• To investigate particles propelled by diffusiophoretic mechanisms.

Main Methods:

• Deduction of coupled Langevin equations from fluctuating chemohydrodynamics.
• Incorporation of fluctuating boundary conditions at the fluid-particle interface.
• Ensuring consistency with microreversibility and Onsager-Casimir reciprocal relations.

Main Results:

• A theoretical model for active particle dynamics driven by self-diffusiophoresis.
• Description of stochastic motion incorporating translation, rotation, and reaction.
• Thermodynamically consistent equations for diffusiophoretic particle dynamics.

Conclusions:

• The derived Langevin equations provide a robust basis for studying active particle motion.
• The model accounts for fluctuations and ensures thermodynamic consistency.
• This framework is crucial for understanding diffusiophoretic propulsion mechanisms.