US Patent 7803262 - Alignment of nanotubes using magnetic nanoparticles

http://ip.com/patent/US7803262

The alignment of carbon nanotubes is important to optimizing the strength as well as the electrical and thermal conductivity of nanotube composites. Several techniques have been developed to achieve this alignment based on the use of fluid flow and electrostatic fields. This patent from Florida State University teaches another method based on the application of a magnetic field on magnetic nanoparticles attached to the nanotubes. Claim 1 reads:

1. A method for aligning carbon nanotubes, the method comprising:

adding magnetic nanoparticles to the carbon nanotubes dispersed in a fluid medium to form a dispersion of magnetic nanoparticles and carbon nanotubes;

adsorbing the magnetic nanoparticles directly to the carbon nanotubes dispersed in the fluid medium to form a magnetic particle-carbon nanotube composite dispersed in the fluid medium; and

placing the magnetic particle-carbon nanotube composite dispersed in the fluid medium between magnets to expose the magnetic particle-carbon nanotube composite in the fluid medium to a magnetic field effective to align the nanotubes of the magnetic particle-carbon nanotube composite dispersed in the fluid medium.