Functionalized multiwalled carbon nanotubes by grafting hyperbranched polysiloxane

Multi-walled carbon nanotubes (MWCNTs) are grafted with hyperbranched polysiloxane (HBPSi) by an efficient hydrosilylation method. In this hydrosilylation process, hydroxylated MWCNTs (HO-MWCNTs) are first functionalized by triethoxyvinylsilane to introduce carbon-carbon double bonds (C=C) on the surface of MWCNTs. The C=C is then reacted with the monomer of methylbis(dimethylvinylsiloxy)silane in the presence of the platinum-carbon catalyst, thus HBPSi is ultimately grafted on the surface of MWCNTs. Fourier transform infrared spectrometry (FTIR), Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) are employed to characterize the changes in MWCNTs surface morphology, chemistry and physical conditions at different processing stages. The content of HBPSi on the surface of MWCNTs was also measured by the thermogravimetric analysis (TGA). The results indicate that the HBPSi successfully grafted on the surface of MWCNTs, and the dispersion of MWCNTs in organic solvent is also improved after functionalization.