The electromagnetic interference shielding effectiveness of high aspect-ratio SiC nanofibers/epoxy composites. Issue 113 (2nd November 2015)

• Record Type: Journal Article
• Authors: Zhang, Yi; Wang, Zhou; Zhang, Boliang; Zhao, Guang-Lin; Guo, S. M.
• Is Part Of: RSC advances. Volume 5:Issue 113(2015)
• Page Start: 93499
• Page End: 93506
• Publication Date: 2015-11-02
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra16007c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Silicon carbide nano-fibers with high aspect ratio improve the EMI shielding effectiveness of epoxy at low concentration. Abstract : This paper presents the measured electromagnetic interference (EMI) shielding effectiveness of silicon carbide nanofibers (SiCNFs)/epoxy composites and the associated shielding mechanism. After obtaining silicon carbide nano-fibers, with an aspect ratio up to 300, SiCNFs/epoxy composites were prepared using an effective dispersion method. The relative complex permittivity, permeability, and EMI shielding effectiveness (SE) of the composites were measured in the frequency range of 26.5–40.0 GHz. The addition of SiCNFs was found to improve the EMI SE at a low threshold value of 10 wt% concentration. At this concentration, the EMI SE was larger than 10 dB over the entire range of 26.5–40.0 GHz, and had a maximum value of 22.9 dB at 40.0 GHz, corresponding to a more than 99% reduction of EMI radiation. The increased polarization interface/boundary and the formed effective conductive network were believed to be responsible for the enhancement of EMI SE, due to the addition of high aspect ratio SiCNFs. Shielding mechanism was studied by resolving the total SE into absorption and reflection portions. Absorption was found to be the major shielding mechanism and reflection had a secondary shielding effect for the threshold SiCNFs concentration case.