1. Spectroscopic characterizations of carbon nanotubes

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 [6].

 

[1] T. Okazaki et al., Nano Lett., 5, 2618 (2005).
[2] T. Okazaki et al., Chem. Phys. Lett., 420, 286 (2006).
[3] T. Okazaki et al., J. Am. Chem. Soc., 130, 4122 (2008).
[4] S.-K. Joung et al., Phys. Rev. Lett., 103, 027403 (2009).
[5] T. Eitoku et al., Mater. Exp., 3, 37-42 (2013).
[6] ISO TS 10867, Nanotechnologies - Characterization of single-wall carbon nanotubes using near infrared photoluminescence spectroscopy

2. Advanced CNTs for bio-applications

Single-walled carbon nanotubes (SWCNTs) can offer a suitable interior space for accommodating molecules [1]. The nanostructures produced by incorporating such molecules into SWCNTs are expected to exhibit several superior features. For example, the encapsulated materials are isolated from active molecules by the tube wall, which leads to their superior durability. Furthermore, the outer surface of SWCNTs can be functionalized covalently or non-covalently, independent of the encapsulated molecules. [8, 9] Proper functionalization of the tube wall leads to a high selective targeting ability to the particular cells or tumors. Now we are developing CNT-based drug delivery system for neutron capture therapy.

 

[1] T. Okazaki et al., Angew. Chem. Int. Ed., 50, 4853-4857 (2011).