Controlled Oxidative Cutting of Single-Walled Carbon Nanotubes

Abstract

The oxidation reaction of piranha solutions with purified HiPco carbon nanotubes was measured as a function of temperature. At high temperatures, piranha is capable of attacking existing damage sites, generating vacancies in the graphene sidewall, and consuming the oxidized vacancies to yield short, cut nanotubes. Increased reaction time results in increasingly shorter nanotubes. However, significant sidewall damage occurs as well as selective etching of the smaller diameter nanotubes. On the other hand, room-temperature piranha treatments show the capability of cutting existing damage sites with minimal carbon loss, slow etch rates, and little sidewall damage. Combined with a method of introducing controlled amounts of damage sites, these room-temperature piranha solutions have the potential to yield an efficient means of creating short, cut nanotubes.

Confined propagation of covalent chemical reactions on single-walled carbon nanotubes

“…The propagation mechanism of this chemistry makes it possible to progressively add new functional groups to the graphene lattice without nucleating unintended new defects. This defect-activated chemistry bears a remarkable analogy to the high reactivity of nanotube ends 13,14 and step edges in surface science 15,16 . Confinement of the reaction to carbon nanotube 'sp 3 step edges' leads to reaction fronts initiated at defect sites that ultimately propagate along the tubular direction at a constant rate (Fig.…”

A study on the dependence of structure of multi-walled carbon nanotubes on acid treatment

“…But low purity of the MWNTs and hydrophobic and inert nature of the surface of MWNTs reduce their applications. The oxidation of MWNTs by using wet chemical [1][2][3][4][5][6][7][8][9], photo oxidation [10][11][12][13], gas phase treatment [13], and oxygen plasma [10] method is a basic technique for purification and also improvement of the chemical reactivity of the MWNTs.…”

In vivo Toxicity Studies of Pristine Carbon Nanotubes: A Review

“…Nevertheless, this methodology has an impact on the tubes. Strong acid conditions cut the tubes in shorter pieces and generate carboxylic functions at the tips and around the sidewalls where the curvatures of the tubes present a higher strain (Ziegler et al, 2005).…”

“…Moreover, nanoscale dispersed SWNTs are taken up by alveolar macrophages and cleared from the lung over time (Mutlu, Budinger et al, 2010). Besides, by administering unpurified CNTs, the authors (Mutlu, Budinger et al, 2010) avoided a potential effect due to surface defects of tube sidewalls (Ziegler et al, 2005), which might contribute to an increase in collagen deposition (Mercer et al, 2008).…”