A facile method to improving the electromagnetic interference shielding of a free-standing and foldable carbon nanotube mat

The electromagnetic interference (EMI) shielding effectiveness (SE) of carbon nanotube (CNT) mats is usually limited by the low solubility of ferrocene in the reaction solution. In this study, an approach was used to prepare a CNT based composite mat with high mass percentages of iron nanoparticles, by pumping ferrocene/methanol solution into a reactor using a secondary quartz capillary at high temperatures. Consequently, free-standing and foldable mats with high saturation magnetization of 57.3 emu g −1 and low sheet and volume electrical resistance of 10.8 Ω sq. −1 and 2.0 × 10 −3 Ω cm were obtained. Thus, a high EMI SE of 40.4-60.3 dB can be achieved over frequency ranges of 1 GHz to 18 GHz with a low mat thickness of 1.0 μm. Due to its high flexibility and remarkable EMI SE properties, the free-standing and foldable CNT mat has potential applications in the shielding field. Free-standing and foldable CNT mats with high saturation magnetization and low electrical resistance were prepared, and a high EMI SE of 40.4-60.3 dB can be achieved at frequency ranges of 1 GHz to 18 GHz with a low mat thickness of 1.0 μm.