Well-dispersed carbon nanotube/polymer composite films and application to electromagnetic interference shielding

Flexible and easily-processable materials exhibiting excellent electromagnetic interference (EMI) shielding performance are desirable for EMI shielding applications in electronic devices, which are getting progressively smaller and smarter. This study reports single-walled carbon nanotube (SWCNT)/poly(ethylene-alt-maleic anhydride) (PEMA) composite films with an excellent EMI shielding performance fabricated by a simple bar-coating and doping process. The AuCl3-doped SWCNT/PEMA composite films exhibited an excellent EMI shielding effectiveness (SE) of 96.3 dB at a thickness of 0.031 mm. The EMI SE values of the AuCl3-doped SWCNT/PEMA composite films are higher than any other reported synthetic materials with a similar thickness. The excellent EMI shielding performance is attributed to the high electrical conductivity. The conductivity of the SWCNT/PEMA composite films can be increased effectively to 8500 S cm(-1) through the AuCl3-doping process. It was further confirmed by MD simulations that the introduction of only 30 wt.% PEMA polymer is effective for obtaining well-dispersed SWCNTs in the composite films. It is noteworthy that such a small fraction of PEMA polymers is advantageous both for decreasing the volume fraction of the insulating polymers and facilitating the chemisorption of dopants onto the SWCNT surfaces. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.