The effects of gamma-irradiation dose on chemical modification of multi-walled carbon nanotubes.

Multi-walled carbon nanotubes (MWNTs) irradiated with gamma-rays were subjected to chemical modification with thionyl chloride and decylamine. Products from chemical treatment were characterized by both FTIR and Raman spectra. Element analysis (EA) and thermogravimetric analysis (TGA) for the modified soluble MWNTs (s-MWNTs) indicated that gamma-radiation increased the concentration of functional groups bound to MWNTs, which arose due to the increasing number of defect sites created on the MWNTs by gamma-photons. Compared with untreated MWNTs, gamma-irradiation significantly enhanced the solubility of MWNTs in acetone and tetrahydrofuran (THF). We therefore conclude that gamma-irradiation provides a novel approach to prepare various functionalized modifications of carbon nanotubes (CNTs).