Squires, Todd M.; Bazant, Martin Z.
We describe the general phenomenon of âinduced-charge electro-osmosis’ (ICEO) –
the nonlinear electro-osmotic slip that occurs when an applied field acts on the ionic
charge it induces around a polarizable surface. Motivated by a simple physical picture,
we calculate ICEO flows around conducting cylinders in steady (DC), oscillatory (AC),
and suddenly applied electric fields. This picture, and these systems, represent perhaps
the clearest example of nonlinear electrokinetic phenomena. We complement and
verify this physically motivated approach using a matched asymptotic expansion to the
electrokinetic equations in the thin-double-layer and low-potential limits. ICEO slip
velocities vary as u_s â E_0^2
L, where E_0 is the field strength and L is...
(533469 bytes; application/pdf) - 23-jun-2010