I&EC 220 |
| Sang-Yong Ju, Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, University of Connecticut, 97 North Eagleville Road, U-136, Storrs, CT 06269, Marcel Utz, Institute of Materials Science, University of Connecticut, 97 N Eagleville Rd U-136, Storrs, CT 06269-313, and Fotios Papadimitrakopoulos, Nanomaterials Optoelectronics Laboratory, Department of Chemistry, Polymer Program, Institute of Materials Science, University of Connecticut, 97 North Eaglville Rd, U-3136, Storrs, CT 06269. |
| Single wall carbon nanotubes (SWNTs) have drawn considerable attention from the scientific community based their unique 1-D electronic and optical properties. These properties are greatly dependent on type (semiconducting (sem-) versus metallic (met-)), diameter and chirality. Recently, several methodologies have come forward in order to separate sem- from met-SWNTs. Using the preferential affinity of amines towards sem-SWNTs, our group has been able to attain bulk separation by type based on a differential solubilization technique. It has been argued that stable dispersions of sem-SWNTs with surfactant-amines originate from the organization of the aliphatic chain along the nanotube sidewalls, along with a small amount of zwitterions. We hereby present a careful design of these surfactant amines to impart differentiation in the 1H and 13C NMR chemical shifts of the various carbon atoms along the linear alkyl chain. This permitted us to determine the localized environment along the surfactant alkyl chains as a function of distance from the nanotube, as well as the chemical affinity of the amine head toward the sem-SWNTs. Our findings suggest that the amine heads are firmly attach to the surface of the sem-SWNTs (or their bundles thereof), while the carbons at the opposite end of the surfactants exhibit substantial mobility. ACKNOWLEDGEMENTS Financial supports from NSF, AFOSR and ARO are greatly appreciated. E-mail : papadim@ims.uconn.edu |
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Purification, Separation, and Characterization of Single-Walled Carbon Nanotubes (SWNT's) (sponsored by Advanced Materials & Nanotechnology Subdivision)
8:30 AM-12:15 PM, Wednesday, March 31, 2004 Marriott -- Orange County 2, Oral
Division of Industrial and Engineering Chemistry |