Flexible Polypyrrole-Coated Polyamide Based Mats for Broadband Microwave Absorption and Electromagnetic Interference Shielding with Low Reflection

Electromagnetic interference (EMI) -shielding and microwave-absorbing materials are of great significance in the fields of microelectronics and telecommunication to achieve electromagnetic protection and compatibility. However, it still remains a challenge to design and fabricate materials integrating both microwave absorbing and shielding properties. In this study, we prepared fluffy and porous EMI shielding materials via facile vapor deposition of pyrrole (Py) on commercial polyamide fibrous mats (FMs). The uniform polypyrrole (PPy) coating on the fiber surface endows the FM with a favorable three-dimensional (3D) conductive network. By the combination of a highly porous microstructure, the fabricated polyamide fibrous mat@polypyrrole (FM@PPy) presents excellent microwave-absorbing and EMI-shielding properties. The EMI shielding efficiency (EMI SE) of FM@PPy can reach 40 dB with a high absorption coefficient (A) of 0.8, showing extremely low reflection with "green" EMI shielding characteristics in the whole X-band (8.2–12.4 GHz). Meanwhile, the reflection loss (RL) of FM@PPy is less than −10 dB in the X-band. Moreover, FM@PPy also exhibits favorable stability and reliability as a wearable sensor. The FM@PPy demonstrates promising potential for "green" EMI shielding, broadband microwaves absorbing and highly stable intelligent sensor.