From high pressure radial collapse to graphene ribbon formation in triple-wall carbon nanotubes
Autor: | Silvio D. Silva-Santos, Morinobu Endo, Nicholas Blanchard, Rafael S. Alencar, Hisakazu Muramatsu, A. L. Aguiar, Yoong Ahm Kim, Alfonso San-Miguel, A. G. Souza Filho |
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Rok vydání: | 2019 |
Předmět: |
Nanotube
Materials science Phonon Graphene Collapse (topology) 02 engineering and technology General Chemistry Carbon nanotube 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics 0104 chemical sciences law.invention Condensed Matter::Materials Science symbols.namesake law Transmission electron microscopy Ribbon symbols General Materials Science 0210 nano-technology Raman spectroscopy |
Zdroj: | Carbon. 141:568-579 |
ISSN: | 0008-6223 |
DOI: | 10.1016/j.carbon.2018.09.076 |
Popis: | The radial stability and the irreversible transformation of triple-wall carbon nanotubes (TWCNTs) bundles are investigated at high pressure conditions both experimentally and theoretically (exp. up 72 GPa). The tubes having a mean internal diameter of 0.83 nm and graphite-like intertube distance, show an onset of the radial collapse evidenced by the evolution of optical phonons. The nanotube collapse onset is observed at ∼ 22 GPa completes for the two external tubes at ∼ 29 GPa, however the innermost tube remains stable up to ∼ 37 GPa. Molecular dynamic calculations performed on smaller diameter TWCNTs bundles, as a model system, confirmed the multiple-stage pressure-induced collapse process. An analytical expression for the collapse pressure of carbon nanotubes having an arbitrary number of walls is proposed. Our experiments and modelling show that for pressures beyond ∼ 60 GPa an irreversible structural transformation of TWCNTs takes place. Ex situ transmission electron microscopy characterization on the recovered sample from 72 GPa revealed the mechanical failure of carbon nanotubes which evolve towards ribbon-like structures as corroborated by Raman spectroscopy. Modelling the tubes evolution at high pressure and high temperature showed the formation of new structures ranging from ribbon-like to graphite-like with either different degrees of amorphization or s p 3 interlinking. |
Databáze: | OpenAIRE |
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