Preparation and microwave absorbing property of silver-coated graphite nanosheet NanoG with Pyrrole

Microwave absorbing material PPy/Ag/NanoG was prepared by in situ polymerization of Pyrrole on the surface of silver-coated conductive graphite nanosheet (Ag/NanoG). The morphologies and nanostructures of PPy, Ag/NanoG and PPy/Ag/NanoG were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy analysis (EDS) and X-ray diffraction analysis (XRD) respectively. Results show that Ag/NanoG has layered structure with high aspect ratio (width-to-thickness) and most of Ag/NanoG nanoparticles are encapsulated by PPy. Measurement of electromagnetic parameters shows that the complex permittivity (epsilon* = epsilon'-j epsilon ''), complex permeability (mu* = mu'-j mu ''), dielectric loss tan delta(e) = epsilon ''/epsilon' and magnetic loss tan delta(m) = mu ''/mu of PPy/Ag/NanoG are superior to those of PPy. The reflection loss of PPy/Ag/NanoG is below -15 dB at the X band from 8.2 GHz to 12.4 GHz and the minimum loss value is -18.21 dB at 9.86 GHz. (C) 2011 Elsevier B.V. All rights reserved.