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Inner- and outer-wall sorting of double-walled carbon nanotubes.

Han LiGeorgy GordeevSören WasserrothVenkata Sai Kiran ChakravadhanulaShyam Kumar Chethala NeelakandhanFrank HennrichAdo JorioStephanie ReichRalph KrupkeBenjamin Scott Flavel
Published in: Nature nanotechnology (2017)
Double-walled carbon nanotubes (DWCNTs) consist of two coaxially aligned single-walled carbon nanotubes (SWCNTs), and previous sorting methods only achieved outer-wall electronic-type selectivity. Here, a separation technique capable of sorting DWCNTs by semiconducting (S) or metallic (M) inner- and outer-wall electronic type is presented. Electronic coupling between the inner and outer wall is used to alter the surfactant coating around each of the DWCNT types, and aqueous gel permeation is used to separate them. Aqueous methods are used to remove SWCNT species from the raw material and prepare enriched DWCNT fractions. The enriched DWCNT fractions are then transferred into either chlorobenzene or toluene using the copolymer PFO-BPy to yield the four inner@outer combinations of M@M, M@S, S@M and S@S. The high purity of the resulting fractions is verified by absorption measurements, transmission electron microscopy, atomic force microscopy, resonance Raman mapping and high-density field-effect transistor devices.
Keyphrases
  • walled carbon nanotubes
  • high density
  • atomic force microscopy
  • electron microscopy
  • ionic liquid
  • high speed
  • high resolution
  • single molecule
  • drug delivery
  • liquid chromatography
  • energy transfer
  • structural basis