Flexible Silver Nanowire and Ti3C2Tx MXene Composite Films for Electromagnetic Interference Shielding

In various fields, the innovation of optoelectronic devices crucially depends on flexible, transparent materials that shield against electromagnetic interference. Herein, the fabrication of flexible transparent electromagnetic interference shielding effectiveness (EMI SE) composite films on PET substrates is achieved using silver nanowires (Ag NWs) and two-dimensional nanosheets (Ti3C2Tx). The uniform Ag NWs with high aspect ratio as a basic conductive network are synthesized using a modified polyol method, which is further optimized through combining with two-dimensional multilayer MXene nanosheets. The Ag NW/MXene composite films acquire a sandwich structure after sequential layering of Ag NW/MXene, finalized by spin-coated PMMA layer. It is worth noting that the addition of MXene nanosheet can decrease surface roughness and increase conductivity via filling the gap of Ag NW network. The Ag NW4/MXene4 composite films with excellent photoelectric performance are suitable for the commercial applications considering the production costs. Furthermore, the fabricated Ag NW/MXene/PMMA composite films demonstrate exceptional flexibility, maintaining integrity after 10 000 continuous bending cycles, and exhibit remarkable stability under harsh conditions, specifically in environments of 80 °C and 80% relative humidity (RH) for duration of 30 days. By finely tuning the concentrations of Ag NW and MXene nanosheets, these composite films attain significant EMI SE level of 35 dB in the X-band. In the EMI shielding mechanism, the absorption component of the shielding effectiveness (SE) is shown to play an important role. The integration of MXene into the composite film markedly improves its EMI shielding effectiveness by boosting the conductivity of the Ag NW network. Furthermore, the multireflection originating from the inner MXene nanosheet is another pathway to promote the EMI shielding performance, which is always neglected for the thin films. Taken together, the introduction and understanding of MXene into Ag NW transparent films provide inspiration for the development of advanced EMI shielding materials for wide applications.