Multiwalled Carbon Nanotube Buckypaper/Polyacrylonitrile Nanofiber Composite Membranes for Electromagnetic Interference Shielding

Polymer composites have been explored for electromagnetic interference (EMI) shielding materials instead of metals due to their low density and flexibility. However, the insufficient EMI shielding effectiveness (EMI SE) caused by the loss of the conducting pathways within the filler-to-filler contacts inside the polymer matrix limits the use of polymers. Herein, we demonstrate a facile and scalable approach for preparing ultrathin and lightweight multiwalled carbon nanotube (MWCNT) buckypaper/electrospun polyacrylonitrile (PAN) nanofiber (BP/NF) composite membranes via electrospinning, thermal-rolling, and vacuum filtration. The smooth surface, higher surface energy, and high mechanical strength of 19 MPa were dependent on the enhanced interfacial network between the BP and NF substrates, thermal-rolled at 130 °C. Furthermore, a superior specific shielding efficiency of 13 734 dB cm2 g–1 was achieved for the 100 μm thick BP/NF composite membrane, which is superior to most of the previously reported MWCNT/polymer composite membranes. This study demonstrates a critical breakthrough for the application of the polymer composites for applications in portable, wearable electronics and military equipment.