73a Characterization of Length Fractionated Single Walled Carbon Nanotubes

Jeffrey A. Fagan, Matthew L. Becker, Jeffrey R. Simpson, Jaehun Chun, Barry J. Bauer, Angela R. Hight Walker, and Erik K. Hobbie. Polymers Division, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899-8542

The optical properties of length separated single walled carbon nanotubes (SWCNTs) separated by both size exclusion chromatography and centrifugation in a high density medium will be presented. SWCNTs were characterized by UV-visible-near infrared absorption and fluorescence spectroscopy, dynamic light scattering, Raman scattering, small angle neutron scattering, and atomic force microscopy. Comparisons will be made between the exhibited behavior of the same length SWCNT populations dispersed and separated via different procedures. The longest SWCNTs populations become colored without any chirality separation and display excellent optical properties. Length dependence of the absorbance, fluorescence and Raman spectra are observed in both systems; differences between the measured values for DNA and deoxycholate dispersed SWCNTs fractions are attributable to the dispersing agent.