Chromatographic separation of single wall carbon nanotubes
Size exclusion chromatography (SEC) is shown to be an effective method to characterize single wall carbon nanotube (SWNT) dispersions. SEC separates nanotube dispersions by size, and measures the intrinsic viscosity on-line as a function of hydrodynamic size as is determined by Universal Calibration. This scaling contains information about the shape of the dispersed particles. This characterization method was tested on three representative dispersions: octadecyl amine functionalization in tetrahydrofuran (THF), butyl group functionalization in THF, and DNA wrapping in aqueous solution. Significant differences between the dispersions were found. Small angle neutron scattering (SANS) and atomic force microscopy (AFM) produced results consistent with the SEC method. © 2006 Materials Research Society.