Post-synthesis alignment of chemically modified carbon nanotubes in magnetic fields

In this paper we present an improved procedure to prepare carbon nanotubes bundles functionalized with magnetite nanoparticles. Carbon nanotubes (CNTs) have been modified by hydrophobic adsorption of a carboxylic acid derivative and the previously synthesized magnetite nanoparticles have been attached to the acid groups. Electron microscopy studies show a high density of magnetite nanoparticles on the surface of CNTs. These modified carbon nanotubes become magnetic and can be appropriately oriented by using external magnetic fields.