Purification of Carbon Nanotubes

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Purification ofCarbon Nanotubes
By Rob Sobelman Staples High School Westport, CT
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Purification of Nanotubes

• By T. Ebbesen and P. Ajayan
• Nature, Vol 367, p519
• 10 February 1994

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Understanding Nanoscale
Courtesy of Hanwen Yan
http//www.powersof10.com
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Carbon Nanotube Model
unknown
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Vocabulary

• CNT Carbon Nanotube
• SWNT Single Walled Nanotube
• MWNT Multi-Walled Nanotube
• PLV Pulse Laser Vaporization
• CVD Chemical Vapor Deposition
• A-D Arc-Discharge

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Multi-Walled Nanotube
http//www.research.ibm.com/resources/news/2001042
5_Carbon_Nanotubes.shtml
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The Problem
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Goals

• Separate nanotubes from nanoparticles
• Destroy the nanotube caps

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Method

• Nanotubes are opened and thinned through
  oxidation
• The oxidation occurs over a long period of time
  so that ALL nanotube caps are destroyed and
  nanoparticles are separated

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Before and After
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Results

• The method used was not successful
• The oxidizer could not reach all of the sample
  due to the nanoparticles being intertwined
  (surface area not exposed)

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Next

• They are going to try chemical oxidation instead
  of the type of oxidation they used in this
  experiment
• Chemical oxidation tests have shown that it may
  more controllable in terms of purification

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The End
The next presentation will be on the Purification
of Single-wall Nanotubes http//www.rpi.e
du/choiy/nano/page6.html
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Purification of Single-shell Nanotubes

• By K. Tohji
• Journal of Physical Chemistry
• Vol. 101, p.1974-1978
• 1997

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Single-Walled Nanotube
http//www.research.ibm.com/resources/news/2001042
5_Carbon_Nanotubes.shtml
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The Problem

• There are metal particles that are making the
  yields of SWNTs unpure