Dispersion of carbon nanotubes by chitosan and its cytotoxicity

Stable dispersion of multi-walled carbon nanotubes (MWNTs) has been prepared by using chitosan (CS) as dispersant, and it was quantitatively characterized by UV-Vis-NIR Spectrophotometer. When the sediment time reaches 375 hours, the supernatant concentration of MWNTs declines 18 % for the bare MWNTs suspension, compared with 6.5 % for the MWNTs dispersed by CS. Morphologies of MWNTs were observed by scanning electron micrograph (SEM) and atomic force microscope (AFM) in detail. The results of AFM clearly show the CS is wrapped on the wall of MWNTs. Finally, we study that the cytotoxicity of MWNTs dispersed by CS on cancer cells. Our results show that MWNTs dispersed by CS have no obvious cytotoxicity on Hela cells.