Flexible conductive polymer composite film with sandwich-like structure for ultra-efficient and high-stability electromagnetic interference shielding

Flexible electromagnetic interference (EMI) shielding films with the merits of light -weight, flexibility, and high EMI shielding performance are the essential materials for the consumer electronics and communication products. Herein, we construct a hybrid conductive network based on the electrospinning thermoplastic polyurethane (TPU) film loaded with different dimensional conductive fillers, including 0D FeCl 3 , 1D carbon nanotube (CNT) and 2D graphene nanosheet (GN) to achieve a flexible, light -weight, and ultra -efficient EMI shielding composite film. In specific, the electrospinning porous TPU film is firstly anchored by CNTs assisted by ultrasound to generate the porous TPU/CNT film. Thereafter, the as -prepared porous TPU/CNT film is loaded a GN/CNT/FeCl 3 layer by vacuum -assisted filtration to generate a double -layer GN/CNT/FeCl 3 @TPU/CNT film. Finally, another porous TPU/CNT film is sealed onto the GN/CNT/FeCl 3 @TPU/CNT film by hot -pressing, which fabricates a sandwiched TPU/CNT@GN/CNT/FeCl 3 @TPU/CNT composite film. It is interesting to note that the composite film possesses the ultrahigh EMI shielding value (56.0 dB at 10.0 GHz) in the X -band (8.2 -12.4 GHz) with high flexibility, excellent mechanical properties, long-term durability (acid -base environment resistance and stability after 1000 bends), as well as high thermal conductivity (6.53 W/(m.K)). This work proposes a simple but efficiency strategy to design the flexible EMI shielding film with ultra -high performance and outstanding durability.