Rectification of the Ionic Current through Carbon Nanotubes by Electrostatic Assembly of Polyelectrolytes
Neal R. Scruggs, Joseph W. Robertson, John J. Kasianowicz, Kalman D. Migler
Rectification of the ionic current flowing through nanotubes embedded in a polymeric membrane is achieved by selective adsorption of polycations to the nanotubes mouths. A one-dimensional model of ionic flux through a nanotube with charged entrance regions qualitatively describes current-voltage curves before and after polycation exposure; reversal potential measurements confirm that charge reversal takes place upon polycation adsorption. The inherent simply of this electrostatic approach makes it attractive in membrane and nanofluidic applications employing rectification.