Abstract Submitted to the    NANOTUBE'04 Conference:

Using dielectrophoresis, and taking advantage of the very high polarisability of metallic SWNT, the latter are extracted from mixtures of semiconducting and metallic nanotubes, the separation process being followed by resonant Raman spectroscopy. Different types of dispersing agent were used, and different electrode geometries were tested where the electric field lines are either in the same direction as or perpendicular to the field gradient. The advantages and disadvantages of these different geometries are discussed. The fraction of tubes driven toward the high field gradient region shows an enrichment in metallic nanotubes, as can be deduced from the intensity variations of the radial breathing modes of the two types of tubes in the initial and fractionated product.