Preparation of pyrrole with iron oxide precipitated on the surface of graphite nanosheet

Fe3O4/NanoG was firstly prepared by precipitation reaction of iron oxide (Fe3O4) on the surface of graphite nanosheet (NanoG). Then composites PPy/NanoG, PPy/Fe3O4 and PPy/Fe3O4/NanoG were prepared by in-situ polymerization of the monomer pyrrole polymerized on the surface of NanoG, Fe3O4 and Fe3O4/NanoG. The structures of Fe3O4/NanoG, PPy, PPy/NanoG, PPy/Fe3O4 and PPy/Fe3O4/NanoG were characterized by scanning electron microscopy, energy dispersive spectroscopy, fourier transmission infrared spectroscopy and X-ray diffraction. Results show that NanoG and Fe3O4/NanoG are encapsulated by PPy for the layered structure and their high aspect ratio (300-500). From the thermogravimetric analysis it can be seen that the introductions of NanoG, Fe3O4 and Fe3O4/NanoG into PPy based composites lead them to exhibit better thermal stabilities than pure PPy. The measurements of electromagnetic parameters show that the reflection loss of PPy/Fe3O4/NanoG is below -15 dB at the X band (8.2-12.4 GHz) and the minimum loss value is -18.30 dB at 9.84 GHz, while the reflection loss of PPy/Fe3O4 is below 10 dB at 8.2-12.4 GHz and the minimum loss value is -14.02 dB at 10.26 GHz. The reflection loss of PPy/NanoG is below -10 dB at 8.2-12.4 GHz and the minimum loss value is 13.44 dB at 10.28 GHz. The microwave absorbing properties of PPy/Fe3O4/NanoG, PPy/Fe3O4 and PPy/NanoG are superior to that of PPy. (C) 2012 Elsevier B.V. All rights reserved.