Spectral fingerprinting of structural defects in plasma-treated carbon nanotubes

Abstract

Controlled introduction of defects into aligned multiwalled carbon nanotubes (MWCNTs) was achieved by time-dependent plasma etching. The subsequent morphological changes in MWCNTs have been fingerprinted using Raman and x-ray photoelectron spectroscopy, by which induction of defects by functionalization was confirmed. We found that the introduction of defects along the nanotube body affects all Raman vibrational modes. A systematic analysis of the relationship between D, D′, D*, and G modes leads us to believe that no one peak can be used as an accurate standard for estimation of defects in nanotubes.

Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes

“…The influence of defect densities on the relative Raman intensities has also been studied in multiwalled carbon nanotubes. 57,92 Here, no further increase 57 Figure 3. D-and G-band intensity at exc D 532 nm with respect to degree of functionalization using diazonium reagents.…”

“…93 At present, it is questionable whether the I D /I G 0 -ratio leads to a more accurate determination of the degree of functionalization compared to the conventional I D /I Gratio. Chakrapani et al 92 doubt whether any of these modes can serve as an accurate standard for estimation of defect concentration.…”

Growth and functionalization of carbon nanotubes on quartz filter for environmental applications

“…This treatment results in the destruction of the structure and introduction of carboxylic groups in CNTs. Furthermore, it is rather difficult to control and very harsh for the graphitic walls of CNTs [25][26][27]. Our previous studies show that the CNTs surface can be cleaned and crafted with different functional groups by controlling the conditions of a plasma treatment (rf plasma power, gas composition and pressure) [28,29].…”

Electrical transport measurements of highly conductive carbon nanotube/poly(bisphenol A carbonate) composite

“…The focus of research into carbon nanotubes in recent years has been shifted to understanding the interface, functionalizing the surface of the molecule and on varying the properties of this essentially closed graphene sheet and integrating them ͑functionalized and otherwise͒ with suitable polymers for focused applications in flexible and robust devices. [18][19][20][21][22][23][24][25] The initial research on combining other organic molecules to carbon nanotubes forming a unique composite, was carried out using poly͑p-phenylenevinylene-co-2,5-dioctoxy-m-phenylenevinylene͒ with multiwalled carbon nanotubes ͑MWNTs͒ that resulted in high electrical conductivities, greater polymer stability in the composite form and unusual fluorescent behavior. Since then many studies have been carried out to alter the chemistry of nanotubes in order to tailor their properties to specific requirements.…”