Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Carbon Nanotubes<br />Introduction<br /> & <br />Synthesis<br />
Introduction: Common Facts<br /><ul><li> Discovered in 1991 by Iijima
 Unique material properties
 Nearly one-dimensional structures
 Single - and Multi-walled</li></li></ul><li>Introduction: nanotube structure<br />Roll a graphene sheet in a certain dire...
Zigzag structure
Chiral structure</li></ul>Defects result in bends and transitions<br />
Introduction: special properties<br /><ul><li> Difference in chemical reactivity for   end caps and side wall
 High axial mechanical strength
 Special electrical properties: </li></ul>Metallic<br />  Semi conducting<br />
Synthesis: growth mechanism<br />Metal Catalyst<br />Tip Growth / Extrusion Growth<br />
Upcoming SlideShare
Loading in …5
×

Synthesis of CNTs

1,319 views

Published on

  • Be the first to comment

Synthesis of CNTs

  1. 1. Carbon Nanotubes<br />Introduction<br /> & <br />Synthesis<br />
  2. 2. Introduction: Common Facts<br /><ul><li> Discovered in 1991 by Iijima
  3. 3. Unique material properties
  4. 4. Nearly one-dimensional structures
  5. 5. Single - and Multi-walled</li></li></ul><li>Introduction: nanotube structure<br />Roll a graphene sheet in a certain direction:<br /><ul><li>Armchair structure
  6. 6. Zigzag structure
  7. 7. Chiral structure</li></ul>Defects result in bends and transitions<br />
  8. 8. Introduction: special properties<br /><ul><li> Difference in chemical reactivity for end caps and side wall
  9. 9. High axial mechanical strength
  10. 10. Special electrical properties: </li></ul>Metallic<br /> Semi conducting<br />
  11. 11. Synthesis: growth mechanism<br />Metal Catalyst<br />Tip Growth / Extrusion Growth<br />
  12. 12. Synthesis: overview<br />Commonly Applied Techniques:<br /><ul><li> Chemical Vapor Deposition (CVD)
  13. 13. Arc-Discharge
  14. 14. Laser ablation</li></ul>Techniques Differ in:<br /><ul><li> Type of nanotubes (SWNT / MWNT / Aligned)
  15. 15. Catalyst used
  16. 16. Yield
  17. 17. Purity</li></li></ul><li>Synthesis: CVD<br /><ul><li> Gas phase deposition
  18. 18. Large scale possible
  19. 19. Relatively cheap
  20. 20. SWNTs / MWNTs
  21. 21. Aligned nanotubes
  22. 22. Patterned substrates</li></li></ul><li>Synthesis: laser ablation<br /><ul><li> Catalyst / no catalyst
  23. 23. MWNTs / SWNTs
  24. 24. Yield <70%
  25. 25. Use of very strong laser
  26. 26. Expensive (energy costs)
  27. 27. Commonly applied</li></li></ul><li>Synthesis: arc discharge<br /><ul><li>Relatively cheap
  28. 28. Many side-products
  29. 29. MWNTs and SWNTs
  30. 30. Batch process</li></li></ul><li>Purification<br />Contaminants:<br /><ul><li> Catalyst particles
  31. 31. Carbon clusters
  32. 32. Smaller fullerenes: C60 / C70</li></ul>Impossibilities:<br /><ul><li> Completely retain nanotube structure
  33. 33. Single-step purification </li></ul>Only possible on very small scale:<br /><ul><li> Isolation of either semi-conducting SWNTs</li></li></ul><li>Purification: techniques<br />Removal of catalyst:<br /><ul><li> Acidic treatment (+ sonication)
  34. 34. Thermal oxidation
  35. 35. Magnetic separation (Fe)</li></ul>Removal of small fullerenes<br /><ul><li>Micro filtration
  36. 36. Extraction with CS2</li></ul>Removal of other carbonaceous impurities<br /><ul><li> Thermal oxidation
  37. 37. Selective functionalization of nanotubes
  38. 38. Annealing</li>

×