A reactive molecular dynamics study on the mechanical properties of a recently synthesized amorphous carbon monolayer converted into a nanotube/nanoscroll

• Published in: Physical chemistry chemical physics : PCCP Vol. 23; no. 15; pp. 989 - 995
• Main Authors: Pereira Junior, Marcelo Lopes, da Cunha, Wiliam Ferreira, Galvão, Douglas Soares, Ribeiro Junior, Luiz Antonio
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 22.04.2021
• Subjects: Carbon; Carbon nanotubes; Chemical vapor deposition; Direct conversion; Dynamic mechanical properties; Elastic properties; Graphene; Mechanical properties; Molecular dynamics; Monolayers; Sublimation; Thermal stability; Topology
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d0cp06613c

Recently, laser-assisted chemical vapor deposition has been used to synthesize a free-standing, continuous, and stable monolayer amorphous carbon (MAC). MAC is a pure carbon structure composed of randomly distributed five, six, seven, and eight atom rings, which is different from that of disordered graphene. More recently, amorphous MAC-based nanotubes (a-CNT) and nanoscrolls (a-CNS) were proposed. In this work, we have investigated (through fully atomistic reactive molecular dynamics simulations) the mechanical properties and sublimation points of pristine and a-CNT and a-CNS. The results showed that a-CNT and a-CNS have distinct elastic properties and fracture patterns compared to those of their pristine analogs. Both a-CNT and a-CNS presented a non-elastic regime before their total rupture, whereas the CNT and CNS underwent a direct conversion to fractured forms after a critical strain threshold. The critical strain values for the fracture of the a-CNT and a-CNS are about 30% and 25%, respectively, and they are lower than those of the corresponding CNT and CNS cases. Although less resilient to tension, the amorphous tubular structures have similar thermal stability in relation to the pristine cases with sublimation points of 5500 K, 6300 K, 5100 K, and 5900 K for a-CNT, CNT, a-CNS, and CNS, respectively. An interesting result is that the nanostructure behavior is substantially different depending on whether it is a nanotube or a nanoscroll, thus indicating that the topology plays an important role in defining its elastic properties. Recently, laser-assisted chemical vapor deposition has been used to synthesize a free-standing, continuous, and stable monolayer amorphous carbon (MAC).