Probing structural integrity of single walled carbon nanotubes by dynamic and static compression

Abstract

Équipe 104 : NanomatériauxInternational audienceWe report on a first study of single walled carbon nanotubes (SWCNTs) after application of dynamic (shock) compression. The experiments were conducted at 19 GPa and 36 GPa in a recovery assembly. For comparison, an experiment at a static pressure of 36 GPa was performed on the material from the same batch in a diamond anvil cell (DAC). After the high pressure treatment the samples were characterized by Raman spectroscopy and transmission electron microscopy (TEM). After exposure to 19 GPa of shock compression the CNT material exhibited substantial structural damage such as CNT wall disruption, opening of the tube along its axis (unzipping) and tube shortening (cutting). Dynamic compression to 36 GPa resulted in essentially complete CNT destruction whereas at least a fraction of the nanotubes was recovered after 36 GPa of static compression though severely damaged. The results of these shock wave experiments underline the prospect of using SWCNTs as reinforcing units in material WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim

Single‐Walled Carbon Nanotubes Shock‐Compressed to 0.5 Mbar

“…Their complete destruction occurs at 36 GPa shock compressionthe CNTs are converted to short graphene nanoribbons after 'chopping' and further 'unzipping'. [1] Increasing the shock pressure to 52 GPa, well beyond the limit of structural integrity of the nanotubes, resulted in substantial changes in the structure of the material recovered after the shock where MLG flakes (Figure 2b), mixed with more defective/less ordered phases were observed (Figure 2c). Fast Fourier transformation (FFT) of the square area 1 in the TEM image of Figure 2b shows the fingerprint of the MLG phase with 3 misoriented layers whereas the FFT of the square area 2 shows a more defective part of the MLG flake.…”

“…The material recovered after 36 GPa shock consists of short graphene nanoribbons created by nanotube unzipping and disordered carbon. [1] On the other hand, observation of diamond nano-crystals was reported in the material recovered after shock of MWCNT at 50 GPa [2] or irradiated with high-energy laser pulses. [3] In this work, we extended the dynamic pressure range of our experiment on well-defined SWCNTs to 0.5 Mbar, i.e.…”

Strain‐ and torsion‐induced resonance energy tuning of Raman scattering in single‐wall carbon nanotubes

“…However, analysis of adiabatically deformed tubes is not irrelevant. Adiabatic deformation should be a good approximation for the fast deformation, when the system has no time to relax by induced deformations (). The predicted absolute value of the difference in transition energy shifts between relaxed and adiabatically deformed tubes is large enough to be experimentally observed.…”

“…For each deformation two configurations are examined. The relaxed one, obtained by induced deformation following twisting or stretching (), and the nonrelaxed, adiabatic one, corresponding to a fast deformation when the system has no time to relax in the deformed configuration ().…”

“…Numerous experiments and calculations were carried out on the deformed SWCNTs . It is shown that the RBM energy is not affected by torsional or uniaxial strain .…”