Light-weight carbon fiber/silver-coated hollow glass spheres/epoxy composites as highly effective electromagnetic interference shielding material

Abstract

Highly effective electromagnetic interference shielding materials with light-weight feature are urgently demanded for releasing electromagnetic pollution. In this study, the hollow glass spheres were coated with silver particles to produce electrically conductive microspheres. The Carbon fiber/silver-coated hollow glass spheres (Ag@HGMs)/epoxy composites were manufactured by composites liquid molding process. The electromagnetic interference shielding properties of the composites were investigated in the X-band (8.2–12.4 GHz) range. The Ag@HGMs play a role in filling up the vacancy of the conductive network of carbon fibers in the composites, which not only form new conductive pathways but also act as bridges to connect CFs and provide additional channels for the electron transfer within the composites thus improving the electrical conductivity. The total shielding effectiveness (SE_T) increases with increasing Ag@HGMs loadings and the maximum SE_T is high as 88.1 dB. The increased SE_T dominated by absorption loss SE_A is attributed to the high conductivity and multilayer construction of carbon fiber veil. The maximum specific SE of the carbon fiber/Ag@HGMs/epoxy composites can achieve 128.8 dB cm³/g, simultaneously the tensile strength and modulus can reach 95.6 MPa and 2.71 GPa, which provides a facile and promising strategy for designing and developing light-weight and high performance electromagnetic interference shielding materials.