  Janus particles propel themselves by generating concentration gradients along
their active surface. This induces a flow near the surface, known as the
diffusio-osmotic slip, which propels the particle even in the absence of
externally applied concentration gradients. In this work, we study the
influence of viscoelasticity and shear-thinning (described by the
second-order-fluid and Carreau model, respectively) on the diffusio-osmotic
slip on an active surface. Using matched asymptotic expansions, we provide an
analytical expression for the modification of slip induced by the non-Newtonian
behavior. The results reveal that the modification in slip velocity arising
from polymer elasticity is proportional to the second tangential derivative of
the concentration field. Using the reciprocal theorem, we estimate the
influence of this modification on the mobility of a Janus sphere. The current
study also has direct implications on the understanding of the transport of
complex fluids in diffusio-osmotic pumps.
