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

Abstract

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