Three Dimensional Carbon-Nanotube Polymers

Abstract

Eight fascinating sp(2)- and sp(3)-hybridized carbon allotropes have been uncovered using a newly developed ab initio particle-swarm optimization methodology for crystal structure prediction. These crystalline allotropes can be viewed respectively as three-dimensional (3D) polymers of (4,0), (5,0), (7,0), (8,0), (9,0), (3,3), (4,4), and (6,6) carbon nanotubes, termed 3D-(n, 0) or 3D-(n, n) carbons. The ground-state energy calculations show that the carbons all have lower energies than C(60) fullerene, and some are energetically more stable than the van der Waals packing configurations of their nanotube parents. Owing to their unique configurations, they have distinctive electronic properties, high Young's moduli, high tensile strength, ultrahigh hardness, good ductility, and low density, and may be potentially applied to a variety of needs.

Covalent-bonded graphyne polymers with high hardness

“…One graphyne is readily assembled into diverse covalent-bonded graphyne polymers because of different wrinkling and buckling manners of graphyne layers. The hP16-carbon [36] and oI16-carbon are both 18,18,18-graphyne products. In two polymorphs, the initial sp-hybridized carbon atoms transform into sp 2 -hybridized atoms, and the initial sp 2 -hybridization transforms into sp 3 -hybridization.…”

Homo Citans and Carbon Allotropes: For an Ethics of Citation

“…A veritable torrent of papers followed, recomputing the same structures (together with other hypothetical ones) and calculating all kind of properties,58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68 without citing the older references. The earlier work of Baughman was acknowledged, together with Umemoto 2012, only in two papers 69.…”

Three-dimensional carbon Archimedean lattices for high-performance electromechanical actuators

“…At the neutral charge, (4 4 ) 3D-C has the highest ρ = 2.97 g/cm 3 and (3, 12 2 ) 3D-C has the lowest ρ = 1.67 g/cm 3 . These values are smaller than that of diamond (3.633 g/cm 3 ) and SWNT (∼ 3.0 g/cm 3 ), and are close to that of graphite (2.295 g/cm 3 ) [21]. The low density of the 3D-C ALs is due to their porous structures along the axial z directions.…”