Impregnating epoxy into N-doped-CNTs@carbon aerogel to prepare high-performance microwave-absorbing composites with extra-low filler content

Reducing filler content in microwave-absorbing composites is of great significance and challenging. Via a facile dip-coating method followed by a pyrolysis process, a new type of melamine foam (MF) derived carbon aerogel with in situ grown nitrogen-doped carbon nanotubes was fabricated, without using any externally introduced carbon source. Owing to the formed hierarchical and cellular structures, the prepared composites impregnated with epoxy (MF@GMC/epoxy) exhibit excellent microwave-absorption performance at a low filler ratio. The minimum reflection loss of a 3 mm MF@GMC/epoxy sample reaches -47.5 dB at 12.20 GHz. The effective absorption bandwidth achieves 6.72 GHz (9.22-15.94 GHz) while the filler loading is only 1.3 wt%. The development of MF@GMC/epoxy may pave a new avenue for the high-efficiency microwave absorption materials with extra-low filler loading.

Automated summary

A new type of carbon aerogel with in situ grown nitrogen-doped carbon nanotubes was fabricated through a facile dip-coating method and pyrolysis process, without using any externally introduced carbon source. The hierarchical and cellular structures of the prepared composites impregnated with epoxy (MF@GMC/epoxy) contribute to excellent microwave absorption performance at a low filler ratio.