Free-Standing Polyaniline-Carbon Nanotube Films via Nonsolvent-Induced Precipitation-Filtration for Electromagnetic...

Free-standing polyaniline (PANI)-multiwalled carbon nanotube (CNT) nanocomposite films were prepared via nonsolvent-induced precipitation followed by a vacuum filtration (NIP-F) method. The slow nonsolvent precipitation of PANI facilitated the formation of a well-interconnected PANI-CNT conductive network, with good electrical conductivity ranging from 19.0-60.7 S cm^-1. The nanocomposite films (0.019-0.052 mm thick) demonstrated remarkable electromagnetic shielding effectiveness (SE) across the X-band region, with the thickest film achieving an average total shielding effectiveness (SE_T) of 33.1 dB. Notably, the thinnest film exhibited a specific SE_T of 1182.5 dB/mm, indicating high SE per unit thickness rather than an intrinsic shielding capability independent of thickness. The NIP-F approach yielded thin films with high electrical conductivity and electromagnetic interference shielding performance. These nanocomposite films with SE exceeding the 20 dB threshold required for commercial EMI shielding applications are suitable for electronic devices where lightweight and thin shielding are of primary concern.