CSI will now provide purity evaluations of all materials that it offers for commercial sale. In addition, CSI will undertake purity evaluations of other SWNT samples on a contract basis. The electronic transitions that arise from the band structure of SWNTs give rise to characteristic spectra that may be observed in suitably dispersed samples in the near-IR (NIR) region of the electromagnetic spectrum. This technique can be used to provide quantitative information on the carbonaceous purity of electric arc (EA) produced SWNTs. The metal catalyst content of SWNT samples is available from TGA measurements, and thus these two techniques together can provide the purity of arbitrary samples.
