Tellurium Nanoparticles Incorporated into Electrospun Poly(acrylonitrile) Nanofibers, Followed by Carbonization and Their Poly(dimethylsiloxane) Composites for Electromagnetic Interference Shielding

Miniaturized, flexible, and highly integrated electronic devices have become an essential part of everyday life. This has contributed to a huge increase in the emission of electromagnetic (EM) waves and has resulted in electromagnetic interference (EMI), which can affect the function of the devices. So, high-performance EMI shielding materials assume great importance. Low density and favorable flexibility are desirable properties for these shielding materials. The present study reports tellurium nanoparticles (Te NPs) incorporated into an nitrogen-doped carbon nanofiber (Te-CNF) prepared through electrospinning, followed by carbonization, for EMI shielding applications. Tellurium is a metalloid with a narrow band gap, and the incorporation of Te NPs in carbon nanofiber (CNF) may alter the electronic properties to improve the 3D conductive network. Te NPs also can introduce polarization sites and heterointerfaces in CNF. Te-CNF exhibited an average EMI shielding effectiveness of 37 dB in the X-band region with a thickness of 0.08 mm and a density of 0.499 g cm–1 and possessed a high electrical conductivity of 0.68 S cm–1. Te-CNF exhibited higher SEA values compared to SER due to the synergistic effect of the incorporated Te NPs and nitrogen-doped CNF, such as interfacial polarization, conduction loss, polarization loss, and multiple scattering and multiple internal reflections of EM waves. Poly(dimethylsiloxane) (PDMS), which is a common flexible substrate, has been used to improve the flexibility and ease of handling of the prepared Te-CNF mat. Thus, the EMI shielding property of Te-CNF and the flexibility of the PDMS substrate have been made use of in the composite to achieve a flexible EMI shielding material. The Te-CNF and its PDMS composites are lightweight, flexible, and hydrophobic and exhibit a high EMI shielding property.