Investigation into electrical conductivity and electromagnetic interference shielding effectiveness of silicone rubber filled with Ag-coated cenosphere particles

In this paper, silver film on the surface of cenosphere particles was obtained by an electroless plating method. The Ag-coated cenosphere particles were used as conductive filler in silicone rubber for electromagnetic interference (EMI) shielding applications. The effect of Ag-coated cenosphere particle content on the electrical conductivity and shielding effectiveness (SE) of the silicone rubber composite was investigated. The results indicated that the Ag-coated cenosphere particles mixed in the silicone rubber were not broken and were evenly distributed. The silver film was not oxidized during preparation of the composite. The volume resistivity of the composites decreased and SE was enhanced with increase of the Ag-coated cenosphere particle content. When the Ag-coated cenosphere particle content reached 240 parts per hundred of rubber (phr), the SE values of the silicone rubber composite were typically above 80 dB across the tested frequency range from 100 KHz to 1.5 GHz.