1. Department of Physics, Alternative Energy and Nanotechnology Laboratory (AENL), Nanofunctional Materials Technology Centre (NFMTC), Indian Institute of Technology, Madras 600036, India;2. Department of Physics, Low Temperature Physics Laboratory, Indian Institute of Technology, Madras 600036, India
Abstract:
Novel foam composites comprising functionalized graphene (f‐G) and polyvinylidene fluoride (PVDF) were prepared and electrical conductivity and electromagnetic interference (EMI) shielding efficiency of the composites with different mass fractions of f‐G have been investigated. The electrical conductivity increases with the increase in concentration of f‐G in insulating PVDF matrix. A dramatic change in the conductivity is observed from 10?16 S · m?1 for insulating PVDF to 10?4 S · m?1 for 0.5 wt.% f‐G reinforced PVDF composite, which can be attributed to high‐aspect‐ratio and highly conducting nature of f‐G nanofiller, which forms a conductive network in the polymer. An EMI shielding effectiveness of ≈20 dB is obtained in X‐band (8–12 GHz) region and 18 dB in broadband (1–8 GHz) region for 5 wt.% of f‐G in foam composite. The application of conductive graphene foam composites as lightweight EMI shielding materials for X‐band and broadband shielding has been demonstrated and the mechanism of EMI shielding in f‐G/PVDF foam composites has been discussed.
