A simple strategy for flexible electromagnetic interference shielding: Hybrid rGO@CB-Reinforced polydimethylsiloxane

In this work, we investigate the electromagnetic interference (EMI) shielding properties of blends of easily available carbon black (CB) with high-surface-area reduced graphene oxide in a polydimethylsiloxane (PDMS) matrix. The chemical composition and morphology of the rGO@CB/PDMS composite are characterized using different techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, atomic force microscopy, and field effect scanning electron microscopy. The hybrid filler could effectively improve the electrical conductivity and dielectric loss, and hence the shielding efficiency, and retain its performance even after repeated bending for 100 times. The microwave absorption mechanism of the samples is discussed in detail in terms of their complex permittivity and microstructure. A three-dimensional layered framework is formed within the composite, which in turn leads to multiple reflections of the microwaves at the layer boundaries, subsequently dissipating them as heat due to the presence of conductive CB particles. Because of this, the hybrid rGO@CB/PDMS composite displays superior absorption-dominated shielding property, with a shielding efficiency (SE) of similar to 28 dB. The synergetic effect of the hybrid fillers resulting from multiple reflections suggests new pathways for designing flexible shielding materials for practical EMI applications. (C) 2019 Elsevier B.V. All rights reserved.