Preparation of GNS/PMMA Foams for Electromagnetic Interference Shielding

Graphene nanosheets(GNS)was coated on the surface of foam nickel by electrophoretic deposition,followed by impregnation with polymethylmethacrylate(PMMA).Finally,GNS/PMMA foam composite was obtained by removing the foam nickel template.Morphology and property of the composite were characterized by scanning electronic microscope,transmission electron microscopy,four-probe conductivity meter and scalar measurement system.It has been shown that the three-dimensional network structure of the foam nickel skeleton is completely inherited by the GNS/PMMA foam composite.An interconnected conductive network assisted by PMMA is formed within the GNS,bringing about good electrical conductivity(1.5S·m-1) and electromagnetic shielding property to the material.The electromagnetic-interference(EMI)of the composite with a pore diameter of 0.25mm and a thickness of 1.5mm can reached up to a maximum shielding effectiveness of 12.7dB in the 8-12GHz range,where the loss generated by the absorption is 99%of the total. It indicates that the foam GNS/PMMA composite is a promising EMI shielding material of lightweight and breathability.