Immobilization of highly-dispersed single-walled carbon nanotubes in biocompatible and water-soluble solid matrix

Purified HiPco SWNTs were dispersed in lactose aqueous solutions containing sodium deoxycholate (SDC) as the dispersant, with the assistance of ultrasonication. After removing the large bundles of SWNT by high speed centrifugation, the resulted SWNTs aqueous dispersion was spray-dried, and then the SWNTs-lactose solid dispersions (or composite particles) were obtained. They were mostly of spherically shell-structured shape with several microns in diameter. Vis-NIR spectroscopy and TEM observation revealed that SWNTs presented as small bundles and individual tubes inside the lactose solid matrix. These results indicate that lactose precipitated out from the aqueous droplets in the spray-drying, and transformed to solid matrix rapidly, which prevented the dispersed SWNTs from re-aggregation, thus immobilize the isolated SWNTs inside the matrix. The present solid dispersions can readily be re-dispersed in water and form SWNTs aqueous dispersion. (c) 2008 The Ceramic Society of Japan. All rights reserved.