Characterizing the sensitivity of bonds to the curvature of carbon nanotubes

Abstract

The way the bonding and reactivity of armchair carbon nanotubes depends on the curvature of the nanotube has been investigated using density functional theory. To understand the nature of the interaction between atoms in the nanotube, the Wiberg bond index, natural bond order analysis, and topological electron density analysis have been performed. All these tools confirm that the bonds in the hydrogen-capped carbon nanotubes considered here are primarily covalent. As the diameter of the nanotube decreases and its curvature increases, the covalency (bond order) decreases, a conclusion that is supported by the increase of the bond lengths and also the decrease of the electron density and the energy density along the bond paths as the curvature increases. To shed light on the orbital contribution in bond formation and the most effective interaction between donor bonding orbital and acceptor antibonding orbital, analysis of natural bond orbitals is carried out. We have observed that the higher the nanotube diameter is, the higher the energy gap.

Temperature-dependent brittle-ductile transition of α-graphyne nanotubes under uniaxial tension

“…Considering the importance of chirality on the carbon nanomaterials [45,59], more than 600 cases (49 chiralities belonging to 10 different chiral angles, 13 temperatures from 100 K to 1300 K with an interval of 100 K for each chirality) were chosen to study the effect of chirality on the brittle-ductile transition of the α-GNT. More details can be found in Section S2 of Supporting materials.…”

Confinement Effects of a Noble Gas Dimer Inside a Fullerene Cage: Can It Be Used as an Acceptor in a DSSC?

“…To understand the nature of interaction between the two He atoms both inside and outside fullerene C 36 and C 40 and surrounding C atoms when He 2 is placed inside the cages, the electron density analysis at the bond critical point (BCP) was performed (Deb et al, 2018 ) by employing the Bader's atoms-in-molecules theory (Bader, 1990 ). The corresponding topological descriptors are tabulated in Table 1 and the contour plot of the Laplacian of electron densities at the BCPs are shown in Figure 2 .…”

Carbon Nanomaterials: Synthesis, Functionalization and Sensing Applications

“…Due to the tubular shape, CNTs possess a certain internal volume which can be used to house specific functionalities. Furthermore, the presence of curvature makes CNTs more reactive than pristine graphene and chemical functionalization of their surface may be done more easily [350].…”