Lightweight Flexible and Efficient Electromagnetic Shielding Composites Based on Silver-Coated Glass Microspheres

Composites consisting of silicone rubber and conductive fillers are extensively utilized in electronic devices due to their high performance in the field of electromagnetic interference (EMI) shielding. Traditional electromagnetic shielding polymer composites often use metal fillers such as silver, which suffer from drawbacks such as high costs and increased density. This study details the synthesis of silver-coated glass microspheres (Ag@GMs) via an ethylene glycol activation method, followed by their application in the formulation of lightweight, flexible, and effective EMI shielding silicone rubber composites. The deposition of a silver coating on the surface of the glass microspheres promotes the constitution of three-dimensional conductive networks, achieving a maximum density of 1.83 g/cm3 and an electrical conductivity of 204.63 S/cm. At the core–shell interface of the silver-coated glass microspheres, interface polarization loss and the internal reflection of electromagnetic waves are significantly enhanced, resulting in the electromagnetic shielding efficiency of up to 120 dB. Moreover, the composite exhibits excellent bending resistance and aging stability, indicating its promising potential for EMI protection in wearable, smart, and precision electronic applications.