Hierarchical construction of CNT networks in aramid papers for high -efficiency microwave absorption

Carbon nanotubes (CNTs) incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction. In this work, a strategy of efficient utilization of CNT in producing CNT incorporated aramid papers is demonstrated. The layer-by -layer self-assembly technique is used to coat the surfaces of meta-aramid fibers and fibrils with CNT, providing novel raw materials available for the large-scale papermaking. The hierarchical construction of CNT networks resolves the dilemma of increasing CNT content and avoiding the agglomeration of CNT, which is a frequent challenge for CNT incorporated polymeric composites. The composite paper, which contains abundant heterogeneous interfaces and long-range conductive networks, is capable of reaching a high permittivity and dielectric loss tangent at a low CNT loading, and its complex permittivity is, so far, adjustable in the range of (1.20 - j0.05) to (25.17 - j15.89) at 10 GHz. Some papers with optimal matching thicknesses achieve a high -efficiency microwave absorption with a reflection loss lower than -10 dB in the entire X-band.

Automated summary

In this work, a strategy of efficient utilization of carbon nanotubes (CNTs) in producing CNT incorporated aramid papers is demonstrated. The layer-by-layer self-assembly technique is used to coat the surfaces of meta-aramid fibers and fibrils with CNT, providing novel raw materials available for large-scale papermaking. The hierarchical construction of CNT networks resolves the dilemma of increasing CNT content and avoiding the agglomeration of CNT, which is a frequent challenge for CNT incorporated polymeric composites. The composite paper exhibits a high permittivity and dielectric loss tangent at a low CNT loading, and achieves high-efficiency microwave absorption in the X-band.