Layer-structured silver nanowire/polyaniline composite film as a high performance X-band EMI shielding material

Abstract

Free-standing layer-structured Ag nanowire (Ag-NW)/polyaniline (PANI) composite films were prepared via a novel but simple two-step casting process. The as-prepared layer-structured PANI composite film with 14 vol% Ag-NWs show a very high electrical conductivity (EC) of 5300 S cm⁻¹, a reasonably good mechanical strength of 44 MPa and an excellent electromagnetic interference (EMI) shielding efficiency of above 50 dB over a wide bandwidth of 1.2 GHz. Comparatively, the plain-structured composite counterparts prepared via the commonly used direct-mixing process exhibit a higher percolation threshold, a lower EC of 4234 S cm⁻¹ and an inferior EMI shielding performance of above 50 dB over a narrow bandwidth of 0.4 GHz. In spite of this, the plain-structured Ag-NW/PANI composite films also display a relatively higher EMI SE when compared to other PANI based composites reported previously. This study provides a facile and effective strategy to fabricate layer-structured composite films with excellent EMI shielding efficiency in the X-band, which may find applications in electronic devices and radiation sources.