| Abstract: | Lightweight,flexible,ultrahigh-performance electromagnetic-interference (EMI) shielding materials are urgently required in the areas of aircraft/aerospace,portable and wearable electronics.Herein,1D carbon nanotubes (CNT) and carbon nanofibers (CNF) with 2D edge-rich graphene (ERG) are used to form a lightweight,flexible CNT-ERG-CNF hybrid foam.This foam was fabricated through a self-sacrificial templating chemical vapor deposition process,where nanocarbons bond through covalent bonding,forming a hierarchical 3D hybridized carbon nanostructure.Multistage conductive networks and heterogeneous interfaces were constructed using edge-rich nanocarbons to increase the induced currents and interracial polarization which makes great contributions to achieve high absorption electromagnetic shielding effectiveness (SEA).The CNT-ERG-CNF hybrid foam exhibits EMI shielding effectiveness (SE) exceeding 55.4 dB in the X-band while the specific SE (SSE,SE divided by mass density) achieves 9200 dB cm3 g-1,which surpasses that of nearly all other carbon-based composite materials.Furthermore,the structural stability and durability of the flexible CNT-ERG-CNF hybrid foams is examined by measuring EMI SE after 10000 times cyclic bending.Remarkably,this work not only provides a new idea for preparing hierarchical carbon materials for a wide range of applications,but presents some fundamental insights for achieving higher absorption losses in EMI shielding materials. |
