Generation of curved or closed-shell carbon nanostructures by ball-milling of graphite

End morphology of ball milled carbon nanotubes

“…The temperature during the process also rises up with time, but is around 60°C at the highest, not sufficient to cause carbon nanotube breakage by oxidation. The pressure generated during the ball milling process can often reach 2-6 GPa [16,17]. However, this pressure is still not enough for breaking carbon nanotubes by direct impact.…”

“…Ball milling has been used to modify the morphologies of cup-stacked carbon nanotubes [12], generate different carbon nanoparticles from graphitic carbon for hydrogen storage [13], transform carbon nanotubes into nanoparticles [14], enhance saturation lithium composition in SWNT [15], and generate highly curved or closed shell carbon nanostructures from graphite [16][17][18]. Although the effects of ball milling on modifying carbon morphology is well documented, the mechanism of which is not well understood.…”

Effect of additional nickel on crystallization degree evolution of expanded graphite during ball-milling and annealing

“…Ball-milling can produce a local pressure about 2-6 GPa, and long duration ball-milling can produce a high temperature [10,11], which cause the possibility of this effect. (2) Cushioning effect: the nickel particles may act as 'cushion' to reduce the impact of the steel balls on the EG particles.…”

“…Welham et al [9] reported some ribbons comprised of graphene planes with defects, delamination, translation, warping and curvature. In addition, ballmilling could produce highly curved graphene planes, forming various carbon nanostructures such as carbon nanoarches, onionlike structures, and carbon tubes [10][11][12].…”

Preparation and Consolidation of Alumina/Graphene Composite Powders

“…Several studies have showed that after ball milling, various structures such as scrolls, microballs and ribbons are produced from natural graphite. [10][11][12][13][14][15] Thus, to obtain graphene sheets by ball milling is viable and of low cost.…”