In-situ coalescence of aligned C60 molecules in Peapods

Hybrid carbon nanotubes: Strategy, progress, and perspectives

“…21,47,93 Coalescing encapsulated fullerenes into DWNTs at lower temperature (<700 °C) is possible if annealing is combined with electron irradiation (150-300 kV). 95,96 Interestingly, the latter experiments revealed that the inner tube diameter value is linearly related to that of the outer tube diameter in a manner that results from compromising between the need for the intertube distance to respect the van der Waals gap (∼0.34 nm) and the need for the innertube diameter to maintain the initial C 60 -fullerene diameter (∼0.7 nm). 96 On the other hand, when encapsulated fullerenes are not packed, electron irradiation was shown to induce a random ionization of the contained molecules that were subsequently able to repulse or attract each other, thereby randomly generating back and forth diffusion movements of individual fullerenes or fullerene trains within the nanotube cavity over several nanometers.…”

“…95,96 Interestingly, the latter experiments revealed that the inner tube diameter value is linearly related to that of the outer tube diameter in a manner that results from compromising between the need for the intertube distance to respect the van der Waals gap (∼0.34 nm) and the need for the innertube diameter to maintain the initial C 60 -fullerene diameter (∼0.7 nm). 96 On the other hand, when encapsulated fullerenes are not packed, electron irradiation was shown to induce a random ionization of the contained molecules that were subsequently able to repulse or attract each other, thereby randomly generating back and forth diffusion movements of individual fullerenes or fullerene trains within the nanotube cavity over several nanometers. 93 Obviously, such behaviors were specifically permitted by the encapsulated situation of the fullerenes because no such behavior was observed for fullerenes in bulk fullerite (i.e., nonencapsulated) when electron irradiated.…”

“…60 Regarding the former category (high fullerenes), C 92 is the largest fullerene inserted so far, yet as endohedral fullerenes since C 92 was meanwhile encapsulating gadolinium atoms in the work cited. 88 Of course, elongated capsules obtained from the in situ coalescence of encapsulated C 60 upon electron irradiation, 21,91 laser irradiation, 92 thermal treatment, 47,93,94 and both electron irradiation and thermal annealing combined 95,96 may also be considered high fullerenes (e.g., C 120 is obtained from the coalescence of two C 60 ). In this regard, the ultimate high fullerene possibly encapsulated is an inner SWNT, thereby making the whole become a DWNT that could also be abbreviated as SWNT@SWNT!…”

Filled Carbon Nanotubes: (X@CNTs)

“…Chapter 5b will show that fullerene coalescence may also occur upon several other kinds of treatments, including thermal annealing [103,155], combinations of thermal annealing and electron irradiation [56,156,157] and photon (laser) irradiation [158,159]. Thermal annealing goes in the direction of thermodynamic stability and ultimately can result in the destruction of the tubular morphology then transform the whole peapod material into a graphite-like material.…”