Effect of Finite Electric Double Layer Conductivity on Streaming Current and Electroviscous Effect in Nanochannel Transport

In this paper, the role of finite Electric Double Layer (EDL) conductivity on the Streaming Potential and the resulting Electroviscous effect in pressure-driven nanofluidic ionic transport is investigated. Important dimensionless parameters like the Dukhin number (based on the EDL surface electrical conductivity, the bulk electrical conductivity and the EDL thickness), ratio of the Stern Layer and the Diffuse Layer conductivities and the ratio of the channel height to the EDL thickness are identified as important dimensionless parameters that dictate the contribution of the finite EDL conductivity. For most of the combinations of these dimensionless parameters, the finite EDL effect lowers the strength of the streaming potential and hence the electroviscous action. However, for certain choices of these parameters, particularly for moderate Dukhin number and substantially large zeta potential, finite EDL conductivity effect can actually enhance these effects.