Ultrathin, flexible, and high-strength polypyrrole/Ti3C2Tx film for wide-band gigahertz and terahertz electromagnetic interference shielding

Abstract

High-frequency radio technology, especially fast-growing terahertz technology, brings great convenience to human life but also raises concern about electromagnetic interference. However, it still lacks a high-performance shielding material containing the features of a high shielding bandwidth (in both GHz and THz bands), high shielding effectiveness (SE), high mechanical strength, and small thickness. Here, an ultrathin and flexible polypyrrole/Ti₃C₂T_x (PPy/Ti₃C₂T_x) film with high electromagnetic interference (EMI) shielding performance and high mechanical property was constructed by a vacuum filtration and hot-press process. The inserted PPy chains tightly connected each Ti₃C₂T_x nanosheet, acting as both the out-of-plane electron–transport pathways and elastic hinges between the nanosheets. With only 9 wt% of PPy, an as-fabricated PPy/Ti₃C₂T_x film showed the highest conductivity of ∼780 000 S m⁻¹ and highest tensile strength of ∼200 MPa. The enhanced conductivity and compressed multilayer structure brought remarkable GHz and THz EMI shielding performance. A highest average EMI SE value of 64.5 dB in the GHz range (8.2–40.0 GHz) and a highest value of 71.4 dB in the THz range (0.2–1.6 THz) were delivered by the PPy/Ti₃C₂T_x sample with an ultrasmall thickness of 4 μm. The outstanding comprehensive performances of the PPy/Ti₃C₂T_x film demonstrate its great potential in EMI shielding for next-generation smart and wearable electronics.