Efficient electromagnetic interference shielding of flexible Ag microfiber sponge/polydimethylsiloxane composite constructed by blow spinning

To ensure the normal operation of electronic equipment, electromagnetic interference (EMI) shielding materials are required to mitigate interference from electromagnetic waves (EMWs), whereas, the development of EMI shielding materials with ultra-high EMI shielding effectiveness (EMI SE), excellent flexibility and satisfactory stability under mechanical deformation is still a challenge. In this paper, we constructed a three-dimensional (3D) Ag microfiber sponge (AgMS) with high conductivity and low density using the blow spinning method. We manufactured an AgMS/polydimethylsiloxane (PDMS) composite with extremely high EMI SE and superb flexibility by backfilling PDMS into the AgMS. The EMI SE of the AgMS/PDMS composite can reach 100.4 dB with a thickness of 0.5 mm and an AgMS content of 3.6 vol%. Besides, the AgMS/PDMS composite possesses outstanding mechanical reliability, remaining stable under various deformation conditions. The EMI SE can retain 91% of its initial value after 1600 stretching cycles, 84% after 1600 bending cycles, and 93.5 dB after 1600 compression cycles. Furthermore, the AgMS/PDMS composite also has excellent compression-resilience properties and chemical stability. These key properties suggest that the AgMS/PDMS composite demonstrates great potential for EMI shielding gaskets in the commercial, medical, and aerospace fields.