Surface decoration of graphene by grafting polymerization using graphene oxide as the initiator

Surface functionalization of graphene oxide (GO) by grafting polymer chains to its surface is achieved by direct use of GO as the initiator for polymerization of N-vinylpyrrolidone (NVP). The functionalized GO can be readily dispersed in a variety of solvents which facilitates graphene processing for a wide range of applications. Fourier-transform infrared, X-ray powder diffraction and transmission electron microscopy investigations show that poly(vinylpyrrolidone) is grafted onto the GO surface, and X-ray photoelectron spectroscopy, elemental analysis and conductivity measurements suggest modest reduction of the functionalized GO during the surface-initialized polymerization. Both electron spin resonance and C-13-NMR spectra indicate that breakage of weak bonds at the defects on the GO surface initialized the radical polymerization of NVP.