Covalent chemistry of single walled nanotubes(SWNTs).

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Covalent chemistry of single walled nanotubes
Krishna Prasad Bastola,
Graduate Student, Chemistry Department
Oklahoma State University
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• SWNTs
• High metallic conductivity.
• High tensile strength, high elasticity.
• High chemical and thermal stability.
• Ability to absorb gas molecules as nano
  capillaries.

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Other applications of SWNTs need chemical
modification

• Two types of chemical modification
• non covalent interaction
• Covalent Interaction (functionalization of
  SWNTs)

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Solubility of SWNT as such in different solvents
is about 5mg/50 ml. Solubility increases to
1mg/ml after functionalization. Attachment of
desired moieties in SWNTs possible only in
solution.
AFM of functionalized tube
AFM of unfunctionalized tube
SourceTexas institutes for intelligent bio
nanomaterials, NASA
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Steps involved in functionalization
Introduction of COOH groups Changing COOH to
COCl Amidation of COCl by amine such as
octadecylamine(ODA)
Source J. Mater. Chem.2002,1952
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Schematics of functionalization route.
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Characterization of functionalized SWNTs

• No standard techniques yet.
• ATR good tools to identify functional groups (FG)
• NMR has some application but to interpret spectra
  is difficult
• Raman spectroscopy is useful specially for the
  (FG) in
• side wall of SWNT
• TGA ( thermal gravimetric analysis) used
  extensively as the FG are labile.
• SEM,AFM, TEM, and STM microscopy's are also very
  useful.

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• Potential applications of functional SWNTs.
• Fluorinated SWNTs as cathode in lithium
  electrochemical cell.
• Polyethyleneimine-SWNT in neuronal growth
• Functionalized SWNT as CFM tips

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• Thank You very
  much