Gradient distribution of segregated conductive network in polyvinylidene fluoride nanocomposites to achieve outstanding electromagnetic interference shielding with low reflection

Highly efficient electromagnetic shielding materials have become an increasing requirement for highpower electronic equipment. Nevertheless, there still remains a challenge in achieving excellent electromagnetic interference (EMI) shielding performance with low reflection. Herein, a gradient distribution of segregated conductive network consisting of edge-selectively carboxylated graphene (ECG) nanosheets and carboxylated multi-walled carbon nanotubes (cMWCNTs) in poly (vinylidene fluoride) (PVDF) nanocomposites was first designed to achieve outstanding low reflective electromagnetic shielding performance. The sheets of PVDF nanocomposites with different contents of hybrid ECG-cMWCNTs were stacked and further hot-pressed to fabricate the layered PVDF nanocomposites. The overall EMI shielding effectiveness (EMI SE) performance could be further improved by increasing the overall thickness and the layer number. With a fixed thickness of 2.0 mm, the PVDF@7.5wt%ECG1 -cMWCNTs3 six-layered nanocomposites exhibit excellent EMI SE reaching 79.87 dB with an absorption effectiveness (SEA ) of 79.62 dB. The excellent EMI SE performance was ascribed to the multiple interface reflection of the segregated conductive network. Meanwhile, the gradient distribution of ECG-cMWCNTs endows the nanocomposites with a strong absorption ability. This work provides a novel strategy for fabricating EMI shielding composites with low reflection for application in portable electronic devices. (c) 2024 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.