Orientation and purification of carbon nanotubes using ac electrophoresis

Orientation and purification of carbon nanotubes have been demonstrated using ac electrophoresis in isopropyl alcohol. Nanotubes move towards the electrodes for all frequencies of applied electric field from 10 Hz to 10 MHz. However, carbon particles contained as impurites become harder to move with increasing frequency. The degree of orientation of nanotubes is higher when the frequency is higher and nanotubes are longer.