Nanotechnology White Paper - US Environmental Protection Agency
Nanotechnology White Paper - US Environmental Protection Agency
Nanotechnology White Paper - US Environmental Protection Agency
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8 EPA <strong>Nanotechnology</strong> <strong>White</strong> <strong>Paper</strong><br />
Figure 3. Computer image of a<br />
C-60 Fullerene. U.S. EPA.<br />
Figure 4. Computer images of various<br />
forms of carbon nanotubes.<br />
(Images courtesy of Center for Nanoscale<br />
Materials, Argonne National Laboratory)<br />
Figure 5. “Forest” of aligned carbon nanotubes.<br />
(Image courtesy David Carnahan of NanoLab, Inc.)<br />
(2) Metal-based materials. These nanomaterials include quantum dots, nanogold, nanosilver<br />
and metal oxides, such as titanium dioxide. A quantum dot is a closely packed semiconductor<br />
crystal comprised of hundreds or thousands of atoms, and whose size is on the order of a few<br />
nanometers to a few hundred nanometers. Changing the size of quantum dots changes their<br />
optical properties. Figures 6 and 7 show examples of metal-based nanomaterials.
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