An ultrathin and flexible polymer composite film at a low fraction of reduced graphene oxide for Ku-band electromagnetic interference shielding

Abstract

The development of effective electromagnetic interference (EMI) shielding materials has turned into an extremely important and urgent challenge. The current study presents an ultrathin and flexible polymer, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite thin film, at a very low loading of reduced graphene oxide (rGO) prepared by a straightforward solvent casting approach for efficient EMI shielding application. The homogenous distribution of rGO sheets throughout the polymer matrix has been verified by applying high-resolution scanning and transmission electron microscopy. To clarify the interfacial relationship between the matrix and filler as well as potential changes in phase, the PVDF-HFP/rGO (PrGO) composite films are further analyzed using X-ray diffraction, Raman spectra, Fourier transform-infrared spectra, and contact angle analysis. The PrGO composite film has a 4.2 GPa Young's modulus and a tensile strength of around 64.8 MPa. The Ku-band frequency has been implemented to evaluate PrGO composite films' EMI shielding ability. The ultrathin PrGO composite film (∼80 µm) revealed an efficient EMI shielding effectiveness (SE) of ∼18.3 dB at a meagre rGO fraction (6.75 wt.%). This efficient EMI SE from ultrathin PrGO composite films is due to the well-connected network of rGO sheets inside the PVDF-HFP matrix. This study demonstrates a scalable and effective way to design an ultrathin, lightweight, and flexible composite film for promising EMI shielding applications in the development of miniaturized electronic devices, and aerospace fields.