Coulombic Dragging of Molecules on Surfaces Induced by Separately Flowing Liquids

We demonstrate that ions or polar molecules can be driven by fluctuating Coulombic forces induced by flowing polar liquids at nanometer separations. We simulate this intriguing phenomenon on small ions and polar molecules driven on the surfaces of carbon nanotubes through which a flow of water is passing. Our simulations show that the average velocities of the driven molecules are close to those of the passing liquid. These transport phenomena open the door for many potential applications.