Carbon black incorporated carbon nanofiber based polydimethylsiloxane composite for electromagnetic interference shielding

Abstract

High-performance electromagnetic interference (EMI) shielding materials that are very elastic and flexible, hydrophobic, and of low density are desperately needed to address the rising electromagnetic pollution problem. This study describes the preparation and characterization of an elastic EMI shielding material which is hydrophobic and of low density. Carbon nanofibers (CNFs) incorporated with carbon black super P (CBSP@CNFs) based polydimethylsiloxane (PDMS) composites were fabricated using a combination of electrospinning followed by heat treatment and manual lay-up process. The high electrical conductivity of 2.5 S cm−1 imparted excellent EMI shielding property to CBSP@CNFs. With a thickness of 0.06 mm and a density of 0.63 g cm−3, CBSP@CNFs exhibited high EMI shielding effectiveness (EMI SE) over a wide frequency range (8.2-26.5 GHz). The highest and average values of EMI SE in the range were 55.8 and 50.7 dB respectively. Composites of CBSP@CNFs with PDMS also showed similar behaviour. The CBSP@CNFs with 9 wt% and 16.6 wt% loading of CBSP exhibited 24,837 and 14741 dB cm2 g−1 of absolute EMI SE (SSEt), respectively, which is remarkably higher than the most reported EMI shielding materials. These results suggest that CBSP@CNFs based PDMS composites would be promising for applications as thin, flexible, stretchable, and light EMI shielding materials.

Keywords

• EMI shielding
• Microwave absorption
• Carbon nanofiber
• PDMS composite