Reversible reaction dynamics of self-diffusiophoretic Janus motors
The dynamics of a Janus motor with reversible surface reactions that is
driven out of equilibrium fluxes of reactants and products will be described.
Coupled Langevin equations for the motor velocity and reaction rate that are
consistent with microscopic reversibility are used to derive a fluctuation
formula for the joint probability to find the motor at position r after n
reactive events have occurred in a time t. Thermodynamic consistency requires
the existence of a contribution to the Langevin equations that is reciprocal
to self-propulsion by diffusiophoresis and causes the reaction rate to depend
on an externally applied force. A reversible microscopic model that can be
used to study such phenomena will be discussed.