Separation and Characterization of Double Wall Carbon Nanotube Sub-Populations

Published

July 8, 2010

Author(s)

JiYeon Huh, Angela R. Hight Walker, Hyun W. Ro, Jan Obrzut, Jeffrey Fagan

Abstract

We present the separation of surfactant encapsulated double wall carbon nanotubes (DWCNTs) synthesized by the high pressure carbon monoxide decomposition (HiPco) process by length and electronic characteristics using density gradient ultracentrifugation (DGU). To focus only the behavior of DWCNTs, dispersed DWCNTs were first isolated following the method of Green et al. [1], utilizing the differences in buoyant density of DWCNTs from impurity single wall carbon nanotubes (SWCNTs) and multi wall carbon nanotubes (MWCNTs) contained in the parent soot. The controlled addition of co-surfactants is shown to allow resolution of DWCNTs by electronic structure, as demonstrated through optical absorbance, Raman spectra, and electrical conductivity measurements. Measurements of conducting films prepared from separated fractions exhibit significant property differences in the enriched materials. Additionally by increasing the density difference between the nanotubes and density gradient medium away from the isopycnic point, we further obtained narrow length distributions of DWCNTs. The length dependent intrinsic optical response of DWCNTs is consistent compared with the previously reported values for SWCNTs.

Citation

Journal of Physical Chemistry C

Volume

114

Issue

26

Pub Type

Journals

Keywords

nanotubes, SWCNT, SWNT, DWCNT, DWNT, separation, length

Citation

Huh, J. , Hight Walker, A. , Ro, H. , Obrzut, J. and Fagan, J. (2010), Separation and Characterization of Double Wall Carbon Nanotube Sub-Populations, Journal of Physical Chemistry C (Accessed March 6, 2025)