We report in situ environmental transmission electron microscope observations of the nucleation and growth of multi-wall and single-wall carbon nanotubes formed by the catalytic decomposition of acetylene (C2H2) on Ni/SiO2 catalyst. The growth rate, structure and morphology of the carbon nanotubes formed depended upon reaction temperature and pressure. Under 20-100 mTorr of gas pressures at 480...

Here we continue our previous exploratory work [Huhtala et al., Comput. Phys. Commun. 146 (2002) 30] in investigating carbon nanotube structures under different bending strain conditions by using large-scale molecular dynamics simulations. On the one hand bending strain is obtained by forcing nanotubes of different chirality to a closed toroidal configuration and on the other hand by bending a ...

Computational simulations of macrocycle-encapsulated single-walled carbon nanotubes (SWNTs) and C60 are reported. A molecular mechanical force field method has been used to calculate the physical properties of these complexes. The calculation shows that the macrocycle-encapsulated SWNTs and C60 are more stable than free SWNTs and C60. When macrocycles are bound to SWNTs, energetically stable we...

A non-isolated pentagon rule metallic carbide clusterfullerene containing a heptagonal ring, Sc2C2@Cs(hept)-C88, was isolated from the raw soot obtained by electric arc vaporization of graphite rods packed with Sc2O3 and graphite powder under a helium atmosphere. The Sc2C2@Cs(hept)-C88 was purified by multistage high-performance liquid chromatography (HPLC), cocrystallized with Ni-(octaethylpor...

The atomic structure of graphene edges is critical in determining the electrical, magnetic and chemical properties of truncated graphene structures, notably nanoribbons. Unfortunately, graphene edges are typically far from ideal and suffer from atomic-scale defects, structural distortion and unintended chemical functionalization, leading to unpredictable properties. Here we report that graphene...

Rogue wave patterns in the nonlinear Schrödinger equation are analytically studied. It is shown that when an internal parameter rogue waves (which controls shape and phase of initial weak perturbations to uniform background) large, these would exhibit clear geometric structures, which formed by Peregrine shapes such as triangle, pentagon, heptagon nonagon, with a possible lower-order at its cen...

The cost effective synthesis and patterning of carbon nanomaterials is a challenge in electronic and energy storage devices. Here we report a one-step, scalable approach for producing and patterning porous graphene films with three-dimensional networks from commercial polymer films using a CO2 infrared laser. The sp3-carbon atoms are photothermally converted to sp2-carbon atoms by pulsed laser ...

We present a new and general mechanism for inter-conversion of carbon structures via a catalytic exchange process, which operates under conditions of Frenkel pair generation. The mechanism typically lowers reaction barriers by a factor of four compared to equivilent uncatalysed reactions. We examine the relevance of this mechanism for fullerene growth, carbon onions and nanotubes, and dislocati...

Grain boundaries (GBs) are structural imperfections that typically degrade the performance of materials. Here we show that dislocations and GBs in two-dimensional (2D) metal dichalcogenides MX2 (M = Mo, W; X = S, Se) can actually improve the material by giving it a qualitatively new physical property: magnetism. The dislocations studied all display a substantial magnetic moment of ∼1 Bohr magne...