Applying spatial gradient magnetic field to metallic/semiconducting SWNTs in fluid

A process of sorting metallic single wall carbon nanotubes (SWNTs) from semiconducting SWNTs, comprising:

• A. disposing the metallic SWNTs and the semiconducting SWNTs in a dilute fluid;
• B. applying a varying dipole-inducing magnetic field to the metallic SWNTs and the semiconducting SWNTs in the dilute fluid, including varying the dipole-inducing magnetic field with time so as alternately increase the dipole-inducing magnetic field with time and decrease the dipole-inducing magnetic field with time, and in which the applying a varying dipole-inducing magnetic field includes:
• i. providing an upper dipole-inducing electromagnetic coil and a lower dipole-inducing magnetic coil;
• ii. applying to the upper dipole-inducing electromagnetic coil a current with a sinusoidal profile waveform having a positive slope phase and a negative slope phase;
• and
• iii. applying to the lower dipole-inducing electromagnetic coil a current with a sinusoidal profile waveform that is synchronized with a triangular profile waveform of the current in the upper dipole-inducing electromagnetic coil;
• and
• C. applying a spatial gradient magnetic field to the metallic SWNTs and the semiconducting SWNTs in the dilute fluid, including:
• i. providing an upper gradient electromagnetic coil and a lower gradient magnetic coil;
• ii. applying to the upper gradient electromagnetic coil a current with a sinusoidal profile waveform;
• and
• iii. applying to the lower gradient electromagnetic coil a current with a sinusoidal profile waveform that is opposite the sinusoidal profile waveform of the current in the upper gradient electromagnetic coil.