PHYS 422 |
| The extent of functionalization of single wall carbon nanotubes can be determined using transmission electron microscopy, X-ray photoelectron spectroscopy or Raman spectroscopy but these methods are time consuming, expensive and require expert analysis. We present results indicating that a simple laser dye, rhodamine 101, can be used as a probe to quantitatively measure the extent of functionalization on nanostructured carbon materials and single wall carbon nanotubes through simple UV-Vis and fluorescence spectroscopy. The fluorescence and absorbance properties of Rhodamine 101 are based upon the equilibrium between lactonic, zwitterionic and cationic forms for this compound. The equilibrium depends substantially on the solvent environment, temperature and pH. We discuss first the concept of pH in polar aprotic solvents and its effect on the rhodamine 101 fluorescence. Then we demonstrate how functionalized nanostructured carbon materials appear to disrupt this established equilibrium leading to reproducible spectral changes. |
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PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Physical Chemistry |