A reversible strain-induced electrical conductivity in cup-stacked carbon nanotubes

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

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.

Dynamic encapsulation of corannulene molecules into a single-walled carbon nanotube

Corannulene molecules dynamically encapsulated into a single-walled carbon nanotube form an ordered stack or a partially ordered stack where concave–concave corannulene dimers are the structural motif.

Radical scavenging reaction kinetics with multiwalled carbon nanotubes

Progress in the development of carbon nanotubes (CNTs) has stimulated great interest among industries providing new applications. Meanwhile, toxicological evaluations on nanomaterials are advancing leading to a predictive exposure limit for CNTs, which implies the possibility of designing safer CNTs. To pursue safety by design, the redox potential in reactions with CNTs has been contemplated recently. However, the chemical reactivity of CNTs has not been explored kinetically, so that there is no scheme to express a redox reaction with CNTs, though it has been investigated and reported. In addition, the reactivity of CNTs is discussed with regard to impurities that consist of transition metals in CNTs, which obfuscates the contribution of CNTs to the reaction. The present work aimed at modeling CNT scavenging in aqueous solution using a kinetic approach and a simple first-order reaction scheme. The results show that CNTs follow the redox reaction assumption in a simple chemical system. As a result, the reaction with multiwalled CNTs is semi-quantitatively denoted as redox potential, which suggests that their biological reactions may also be evaluated using a redox potential scheme.