Transient two-liquid electroosmotic flow with electric charges at the interface

The transient aspects of two-liquid electroosmotic (EO) flow are analytically studied, in which a low EO mobility liquid is delivered by the interfacial viscous force of a high EO mobility liquid driven by electroosmosis. The flow of the two liquids depends on the coupling effects between them, which involve the electrokinetic effect. The model accounts for surface charges at the liquid–liquid interface. Due to the presence of the surface charges, the shear stress is not continuous at the interface. Analytical solution of such transient two-liquid flow in rectangular channel is presented by Laplace transform method. The effects of dynamic viscosity ratio, interface potential, kinematic viscosity ratio and parameter of the electric double layer are analyzed to characterize the flow.