The effect of shock wave compression on double wall carbon nanotubes

Abstract

Double wall carbon nanotubes (DWCNTs) have proven to have a very good structural stability when exposed to high static pressures. We report here on the study of DWCNTs after application of shock wave (dynamic) compression up to 36 GPa in a recovery assembly. TEM images of so‐treated samples reveal a threshold between 19 and 26 GPa of shock wave compression above which significant structural damage is induced whereas only minor damage can be detected below. The threshold detected with TEM coincides well with the collapse pressure of DWCNTs previously reported [You et al., High Press. Res. 31, 186 (2011); Aguiar et al., Phys. Chem. C 115, 5378 (2011)]. Raman data demonstrate a gradual accumulation of structural defects via an increase in D‐band to G‐band intensity ratio (ID/IG‐ratio) from ∼0.2 to ∼0.8 in going from the source CNT material to the nanotubes after compression to 36 GPa. Despite severe damage; the DWCNTs exposed to 36 GPa of shock wave compression survived which is evidenced by Raman spectra. The DWCNTs demonstrate a higher susceptibility to structural damage under dynamic than static pressure.

Pressure-induced radial collapse in few-wall carbon nanotubes: A combined theoretical and experimental study

“…By averaging over samples having d in varying from 0.5 to 1.9 nm, some experimental studies proposed that geometrical changes happen already at pressures as low as 3 GPa [35], and the response is elastic up to pressure of at least 10 GPa [36]. Other dynamic high-pressure experiments found that only minor tube structure damage occurs below 19 GPa, with the collapse of the double-wall CNT occurring at $ 26 GPa [37]. However, other works which considered similar diameter distributions reported collapse or large structural modifications at different pressures ranging from $ 13e15 GPa [18,38] to $ 25 GPa [17,39].…”

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

“…The defect density is generally quantified by the D‐band over G‐band intensity ratio ( I D /I G ). The I D / I G data for the source and recovered materials together with previously reported results on DWCNTs exposed to 36 GPa of dynamic compression are presented in Table . Raman spectra of DWCNTs shocked to this pressure exhibit features similar to the spectra of SWCNTs subjected to the similar treatment in the present study.…”

“…Figure shows a schematic view of the shock wave assembly used in the dynamic compression experiments. The details of the experimental procedure can be found elsewhere . The samples were compressed by a stepwise shock and a new sample was loaded for each experiment (i.e., for each shock pressure) but always from the same source batch.…”

“…On the other hand, at ultra‐high pressure the CNTs lose their structural integrity and transform into other nano‐carbon phases – a superhard hexagonal carbon phase was synthesized by compression of multi‐walled CNTs to 100 GPa . Nevertheless, study of DWCNTs under dynamic compression revealed a much lower pressure threshold of “just” 36 GPa for structural stability of DWCNTs with outer diameters of 1.6–12 nm: although a certain fraction of severely damaged nanotubes survived this shock compression, most of the material was destroyed . Therefore, the real top limit of structural integrity of CNTs has not yet been established.…”

Single‐Walled Carbon Nanotubes Shock‐Compressed to 0.5 Mbar

“…The CNT powder was compressed (1.3 g cm −3 ) and placed into a stainless steel recovery assembly of planar geometry . The SWCNTs were exposed to 52 GPa of shock wave compression (the correspondent ramp temperature is estimated at 1496 K).…”