Anisotropic, lightweight and flexible mechanical compression of multi walled carbon nanotubes/polyimide aerogels for outstanding electromagnetic interference shielding

In this study, anisotropic multiwalled carbon nanotube/polyimide (CNT/PI) aerogels were fabricated through facile in-situ polymerization, followed by a directional freeze-drying. The as-prepared CNT/PI aerogels presented anisotropic microstructures and properties along axial (through-plane) and radial (in-plane) directions. In addition, the CNT/PI aerogels exhibited anisotropic electroconductivity, EMI shielding effectiveness (SE) and mechanical performance. The CNT/PI aerogel displayed an enhanced EMI SE of 29.0 dB along in-plane direction and 25.9 dB along through-plane direction in the X-band. Moreover, along in-plane direction, values of SEA/SET and absorption coefficient (A) reached 89.6 % and 72.2 %, respectively illustrating the main shielding mechanism of the CNT/PI aerogel was microwave absorption. Furthermore, the CNT/PI aerogels exhibited anisotropic compression and prior cycling performances. Thus, this study presented a straightforward and efficient method for preparing light anisotropic PI based aerogels.