Design and synthesis of high-performance poly(amide-imide) for multifunctional electromagnetic interference shielding films

Abstract

The exploration of flexible, transparent, anti-corrosion and thermally stable electromagnetic interference (EMI) shielding materials is still a huge challenge and urgently demanded in the civil and military fields. Herein, two novel high-performance poly (amide-imide)s (PAIs) were designed and used to fabricate sandwich structure EMI shielding films through simple layer-by-layer casting method. Combining advantages of PAI and silver nanowires (Ag NWs), PAI/Ag NWs composite films showed a shielding effectiveness (SE) of 35 dB and simultaneously possessed an optical transmittance of beyond 80%. More encouragingly, the composite films remained more than 92% EMI SE with random deformations (>5000 times). Furthermore, benefitting from the excellent properties of PAI matrix and sandwich structure of EMI shielding films, the EMI SE was almost unchanged even when they were exposed to air for 30 min at 160°C. On the other hand, the PAI/Ag NWs composite films still exhibited EMI SE of more than 30 dB when they were dipped into aqueous solution for 1 h by varying pH values from 2 to 13. These results demonstrated that PAI and Ag NWs was a good combination to prepare EMI shielding materials with excellent comprehensive performances.