A novel method of functionalizing carbon nanotubes via neutralization reaction.

Acidic oxidation method has been massively reported as an effective method to functionalize the surface of carbon nanotubes (CNTs). However, these corrosive acids are extremely dangerous. In this paper, CNTs are firstly oxidized in alkaline solution consisting of sodium hypochlorite and potassium permanganate instead of strong acids, and subsequently the mixture is neutralized by hydrogen peroxide solution to complete the secondary oxidation in the process. Experimental results indicate that more defects in CNTs are more likely to form and functional groups are successfully grafted onto CNTs after oxidation. Moreover, zeta potential result shows that the treated CNTs with negative groups have superior suspension stability. Furthermore, the treated CNTs, length of which is shorter than that of the pristine ones, are separated from each other. Meanwhile, the treated CNTs can remain as a colloidal (well dispersed) solution for 30days. [ABSTRACT FROM AUTHOR]