Modified graphene as a conducting ink for electromagnetic interference shielding

Research on electromagnetic interference (EMI) shielding materials has become very important as one looks for polymer composites as EMI shielding paints and coatings. EMI Shielding is mainly dependent on absorption and reflection losses, which in turn depend on conductivity, permittivity and permeability of the material. In the present work, we have tried to use the properties of graphene to improve EMI shielding and absorbing properties of the polymer composite. The work is focussed on two aspects of the materials; firstly, to developed an EMI shielding paint which can be used as coating and secondly, development of such paint which has absorption as the dominant mechanism of shielding. Reduced graphene oxide(rGO) has been conjugated with ferromagnetic nanostructures. Absorption of up to similar to 12 dB for composite of rGO-Fe3O4 and similar to 18 dB for the composite of rGO-Ni was observed, which is more than 99% of the total radiation and hence, can be useful for commercial applications.