Carbon nanotube aerogels are interesting platforms for the manufacture of lightweight composites. To guide the development, we screen with tight-binding atomistic calculations two primary crystalline organizations of nanotubes with 1.4-4.5 nm radii and 1-3 number of walls. Calculations reveal a crossover from polygonized nanotubes with hexagonal close-packing organizations to collapsed shapes organized in stacks. The energies of the two modes are captured into a concise form, which predicts the crossover radii and domains of their dominance. The graphite-like phase formed with collapsed nanotubes allows for ∼1 TPa Young's moduli. Bundles of collapsed nanotubes emerge as natural candidates for the developmnent of ultrastrong composites.
Bibliographical noteFunding Information:
This work was supported by the Institute for Ultra-Strong Composies by Computational Design NASA NNX17AJ32G, NASA NNX16AE03G, and by the University of Minnesota MnDrive and Grant-in-Aid programs. Computational resources were provided by NASA Advanced Supercomputing Division at Ames Research Center, and by the Minnesota Supercomputing Institiute.
© 2020 American Chemical Society.
- Young's moduli
- atomistic calculations
- carbon nanotubes