Single-step in situ preparation of polymer-grafted multi-walled carbon nanotube composites under 60Co γ-ray irradiation

We present single-step in situ syntheses of polystyrene-grafted multi-walled carbon nanotubes (MWNTs) under Co-60 gamma-ray irradiation. Pristine MWNTs were first dispersed in pure styrene under sonication, and polystyrene ( PS) was then covalently attached to the surface of MWNTs when the mixture was subjected to gamma-ray irradiation. The polymer content in PS functionalized MWNTs can be up to similar to 15 wt %, as determined by thermal gravimetric analysis (TGA). The functionalized MWNTs can be dispersed well in common organic solvents such as THF, toluene, and CHCl3, etc. The presence of PS in the functionalized carbon nanotube composites was further evidenced by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM/HRTEM). The mechanism of the irradiation grafting process was also proposed. The reported gamma-ray irradiation grafting technique is expected to be suitable for industrial scale-up preparation of functionalized carbon nanotubes (CNTs).