1. Gas Adsorption in Carbon Nanotubes Northern Arizona University Department of Physics & Astronomy Buddy Davis Mentor: Randy Dillingham

2. Carbon Nanotubes About ten nanometers thick Single walled and double walled Different structure styles Uses Structural Electrical Gas Storage/Filter

3. Etching Etched for one week in.01 molar sulfuric/nitric acid H 2 SO 4 & HNO 3 Etching creates defects in the nanotubes H 2 SO 4 HNO 3

4. Mass Spectroscopy Voltages of mass spec varied to scan Detector shows what masses are present.

5. X-rays shined on sample to eject electrons Energy of emitted electrons based on binding energy of sample atom X-ray Photoelectron Spectroscopy (XPS)

6. Nitrogen Exposure Nanotubes placed in vacuum 5X10-9 TorrNanotubes placed in vacuum 5X10-9 Torr Nitrogen gas was then introduced under a pressure of 1x10-7 Torr for 40 minutesNitrogen gas was then introduced under a pressure of 1x10-7 Torr for 40 minutes The vacuum was then restored to 5X10-9 TorrThe vacuum was then restored to 5X10-9 Torr

7. XPS Data Comparing etched and unetched reveled sulfur left from etching process.

8. XPS Data Significant change in nitrogen found

9. Atomic Concentration Data <.1%<.1%5.5% 94.9%34.4%33.9% 4.5%54.7%46.5%.5%10.9%14.1% Nitrogen Carbon Oxygen Sulfur UEEEE

10. Future Experiments Testing unetched exposed tubes Testing alternative gasses (CF 4 ) Alternative methods of testing such as Fourier transform infrared spectroscopy

11. Thank You