Carbon Nanotube Reinforced Composites: Metal and Ceramic ...

24j 1 Introduction
Table 1.4 Reported DTG results for various impurities in arc-grown SWNTs.
Investigator
The advantages and drawbacks of the analytical techniques mentioned above
for the characterization of purified CNTs are well documented in the literature [119,
120, 131]. Recently, NASA-Johnson Space Center has developed a protocol for the
characterization of purified and raw HiPCo SWNTs [134]. This protocol summarizes
and standardizes analytical procedures in TEM, SEM, Raman, TGA and UV-vis-NIR
measurements both qualitatively and quantitatively for characterizing the material
quality of SWNTs (Table 1.5).
Table 1.5 A protocol developed by NASA-Johnson Space Center
for the characterization of purified and raw HiPco SWNTs.
Parameter Technique Analysis
DTG peak
temperature ( C) Carbonaceous and metal species
Hou et al. [111] 385 Oxidation of metal catalyst
530 Amorphous carbon, carbon nanoparticle
830 SWNT
Harutyunyan et al. [132] 350 Amorphous carbon
400 SWNT
450 Multi-shell carbon
Shi et al. [133] 364 Amorphous carbon
434 SWNT
Itkis et al. [131] 349 Amorphous carbon
418 SWNT
Purity TGA Quantitative-residual mass after TGA in air at
5 C min 1 to 800 C
SEM/TEM Qualitative-amorphous carbon impurities
EDS Qualitative-metal content
Raman Qualitative-relative amount of carbon impurities and
damage/disorder
Thermal stability TGA Quantitative-burning temperature in TGA in air at
5 C min 1 to 800 C, dM/dT peak maximum
Homogeneity TGA Quantitative-standard deviation of burning temperature
and residual mass taken on 3–5 samples
SEM/TEM Qualitative-Image comparison
Dispersability Ultra-sonication Qualitative-time required to fully disperse (to the eye)
low conc. SWCNT in DMF using standard settings
UV-vis-NIR Quantitative-relative change in absorption spectra of
sonicated low concentration SWCNT/DMF solution
Reproduced with permission from [134]. Copyright Ó (2004) Elsevier.