Electrokinetic behaviour of overlapped electric double layers in nanofluidic channels

The ionic concentration variation arising in overlapped electric double layers in nanochannels presents different electrokinetic behaviour from that in microchannels. Using a modified concentration approach, the results reveal that the surface charge density is insensitive to the concentration in the low-salt regime, and a nearly constant streaming conductance is predicted. A scaling analysis confirms that the streaming potential also has a constant value because of length scale effects, but not due to the accumulated charge in the double layer.