Response to Comment on "On the flow field about an electrophoretic particle"

A recent paper of ours [Ref. 1] addressed a number of aspects concerning the flow-field about an electrophoretic particle. Among those, with pertinence to the present Response, the role of surface current within the curved, diffuse Debye layer (DL) (henceforth called simply surface current) in the electric field distribution was investigated. An effective boundary condition [Eq. (8a) in Ref. 1] which incorporates surface current was obtained. The influence on electrophoretic mobility was determined. It was also shown that, for a curved, non-spherical particle, electrophoretic mobility can be significantly anisotropic as a result of the surface-current effect. The importance of this effect was shown to be directly related to the value of the nondimensional number β/l,where l is a characteristic length of the particle and β a constant (with unit of a length) depending on certain physical and physicochemical properties of the fluid and the diffuse DL, besides electrolyte concentration. The whole analysis relies on two major fundamental assumptions: the DL thickness λ is much smaller than a characteristic radius of curvature of the particle (λ/l 1); concentration polarization in the bulk electrolyte (outside the DL) is negligibly small (meaning∇cbc∞/l).