Structural evolution, microwave absorption performance and in-situ compositing of carbon nanotube prepared from biomass-based citric acid and urea

The microscopic characteristics of carbon nanotube play a fundamental role in determining the macroscopic features. This research focuses on synthetic studies toward the structural evolution and microwave absorption enhancement of carbon nanotubes from biomass-based citric acid small organic molecules reaction system. When Co/Fe dual metal catalysts are used, self-entangled carbon nanotube networks in all three dimensions like instant noodles form. Polydimethylsiloxane (PDMS) is introduced inspired by "growth-from-template" strategy, the green hair algae-like morphology with bamboo-like structure is revealed in the carbon nanotubes. Twisted carbon nanotube yarn structure together with quaternary structure of protein-like carbon nanotube are both observed. Carbon microstructural evolution is investigated in bagasse-based ultralight composite. Toward the incident microwaves, in-situ synthesized CNTs-rGO composite has substantially enhanced reflection loss performance. The strongest reflection loss is -44.9 dB at 12.6 GHz with the absorber thickness of only 2 mm. And the effective microwave absorption bandwidth can reach 6.1 GHz covering a frequency range of 11.5-17.6 with the absorber thickness of only 1.6 mm.