One-pot, efficient functionalization of multi-walled carbon nanotubes with diamines by microwave method

Diamines are known to act as a medium to bind miscellaneous compounds to carbon nanotubes (CNT). However, they are commonly applied in a tedious manner. Here, multi-walled carbon nanotubes (MWCNTs) were functionalized by a series of diamine molecules (ethylenediamine, 1,6-hexamethylenediamine and 1,4-diaminobenzen) in a one-pot, rapid microwave-assisted method. Surface functionality groups and morphology of MWCNTs were analyzed by infrared spectroscopy, thermogravimetric analysis, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results consistently confirmed the formation of diamines functionalities on MWCNTs, while the structure of MWCNT has remained relatively intact. This simple and efficient process may play an important role for realizing miscellaneous functionalization of CNTs.

► In this study, three diamines (EDA, HMDA and DAB) were successfully added on the surface of MWCNTs in a microwave-assisted method. ► The procedure was fast, one-pot, simple and resulted in a high degree of functionalization as well as solubility in ethanol. ► For the case of EDA- and HMDA-treated MWCNTs, diamine functionality seems to cross-link the adjacent MWCNTs. ► NaNO2 catalyst was appeared to be fundamental for the functionalization reaction to take place.