Carbon nanotubes change their physical properties depending on the molecular structure such as diameter and wrapping angle. In the last 10 years, characterizations of nanotubes by spectroscopy have been rapidly sophisticated. Our research group has been characterized carbon nanotubes and the related materials by optical spectroscopy [1-5].
As expectations for industrial applications of nanotechnology increase, practical needs for nanotechnology standardization have become widely recognized. Since around 2004 standardization activities of nanotechnology have been launched in the United States, European countries, Japan and China. International Organization for Standardization (ISO) established the new technical committee on nanotechnology (TC229) in May 2005. One of our members (Okazaki) has led a project, NIR-Photoluminescence (NIR-PL) spectroscopy in the characterization of SWCNTs since 2007. The document was approved for publication in 2010 .
 T. Okazaki et al., Nano Lett., 5, 2618 (2005).
 T. Okazaki et al., Chem. Phys. Lett., 420, 286 (2006).
 T. Okazaki et al., J. Am. Chem. Soc., 130, 4122 (2008).
 S.-K. Joung et al., Phys. Rev. Lett., 103, 027403 (2009).
 T. Eitoku et al., Mater. Exp., 3, 37-42 (2013).
 ISO TS 10867, Nanotechnologies - Characterization of single-wall carbon
nanotubes using near infrared photoluminescence spectroscopy