Tunable CoNi microstructures in flexible multilayered polymer films can shield electromagnetic radiation. (15th November 2019)

• Record Type: Journal Article
• Authors: Arief, Injamamul; Bhattacharjee, Yudhajit; Prakash, Om; Sahu, Megha; Suwas, Satyam; Bose, Suryasarathi
• Is Part Of: Composites. Number 177(2019)
• Publication Date: 2019-11-15
• Subjects: Multilayered films -- CoNi microstructures -- Multi-walled carbon nanotubes -- Polymer nanocomposites -- EMI shielding; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2019.107283
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: This paper highlights the outstanding electromagnetic shielding efficiency achieved by constructing layer-wise assembly of polymer films containing CoNi (cobalt-nickel) micro flowers, rods, and microspheres. Following a hydrothermal approach, various CoNi microstructures were synthesized from their metal salt precursors using wet chemistry followed by dispersing them in a PVDF matrix along with conducting multiwalled carbon nanotubes (MWNT) and subsequently hot-compressing them into thin flexible films (of thickness less than 1 mm). Few films were also prepared by dispersing only MWNTs in PVDF to construct a layer-wise assembly following an approach wherein a reflector spacer (PVDF/MWNT composites) is sandwiched between n (n = 0, 1, 2, 3) absorbers (PVDF/CoNi/MWNT composites). The film thickness was adjusted in such a way that the total thickness of each assembly is ca. 0.9 mm. This strategy wherein a reflecting layer is sandwiched between the absorbing layers resulted in an excellent total shielding efficiency (SET ) of −41 dB. By careful control of different layers in this layer-wise assembly, we managed to facilitate significant magnetic losses coupled with conducting losses. Therefore, this paper offers a replacement of conventional metallic shields with unique CoNi-based polymer composites for suppressing EM radiation.