title: Enrichment of single-walled carbon nanotubes by diameter in density gradients.
abstract: The bulk enrichment and separation of single-walled carbon nanotubes (SWNTs) by diameter has been achieved through ultracentrifugation of DNA-wrapped SWNTs in aqueous density gradients. The separation is identified by the visual formation of colored bands of SWNTs in the density range of 1.11-1.17 g cm(-3). The optical absorbance spectra of the separated SWNTs indicate that SWNTs of decreasing diameter are increasingly more buoyant. This nondestructive and scalable separation strategy is expected to impact the fields of molecular electronics, optoelectronics, and sensing where SWNTs of a monodisperse band gap are essential.
authors.affiliation: Department of Materials Science and Engineering, Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208-3108, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Arnold
authors.forename: Samuel I
authors.initials: SI
authors.lastname: Stupp
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hersam
mesh_terms: D002499:Centrifugation, Density Gradient; D004247:DNA / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D004247:DNA