Self-Assembly of Helical Polyacetylene Nanostructures on Carbon Nanotubes

Abstract

The self-assembling of helical polyacetylene (PA) nanostructures on single-walled nanotubes (SWNT) is studied using molecular dynamics (MD) simulations. The results indicate that SWNT can activate and guide the polymer chains helically wrapping onto it through van der Waals interaction and the π−π stacking interaction between the polymer chain and the outer surface of SWNT. The effects of SWNT diameter, SWNT chirality, and PA chain length on the configuration of the nanostructure have been extensively examined. It is found that a DNA-like double helix of two PA chains appears when the diameter of SWNT is larger than about 13.56 Å, the SWNT chirality has a negligible effect on whether the helical process could happen, and the two PA chains can interact with each other and then influence the formation of the perfect double helix. The geometrical structures between PA and SWNT may trigger enormous interests in chemical functionalization and helical polymer synthesis, which may eventually be beneficial for fabricating nanoscale devices. In addition, the self-assembly process of helical nanostructures on SWNT may also be helpful for understanding biological systems at the molecular level and for developing new materials.

Why do the structural properties of complexes formed by glucans and carbon nanotubes differ so much?

“…As for many other chain-like molecules, such as DNA [36][37][38][39] and organic polymers, 21,[40][41][42] there should be other factors aside from the linkage of the polymers that affect the three-dimensional arrangement of polymer-SWCNT hybrids. For example, It is suggested that polymers with stiff and semi-exible backbones tend to wrap around the SWCNT with more distinct conformations than those with exible backbones, 43,44 which partly supports and rationalizes our conclusions.…”

A review of helical nanostructures: growth theories, synthesis strategies and properties

“…Similarly, molecular dynamics simulation also reveals the carbon nanotubes could act as an interesting platform for the self-assembly of other helical nanostructures. [192][193][194][195] These theoretical studies provide some interesting ideas for the helical nanostructures design.…”

Molecular dynamics studies of interfacial crystallization behaviors in polyethylene/carbon nanotube composites

“…In this equation, E inter is the interaction energy between the polymer molecule and the SWCNT, E total is the total energy of the composite, E polymer is the energy of individual polymer molecules and E SWCNT is the energy of individual SWCNTs or the SWCNT bundle. [22][23][24] The interaction energy between PE and a single SWCNT is À296.8 kcal mol À1 , while the interaction energy between PE and a SWCNT bundle is À503.5 kcal mol À1 . According to the energy minimization principle, the PE chain will prefer to stay in the groove rather than another position on the surface of the SWCNT.…”

“…[18][19][20] To reveal the internal mechanism of interfacial crystallization, molecular dynamics (MD) simulation has been considered as an efficient tool for investigating the intermolecular interactions between polymer chains and CNTs. [21][22][23][24] For example, Joo et al compared two kinds of conjugated polymers (PFO-BPy and PFO-BPy:Re) with a different backbone rigidity. They found that the wrapping and unwrapping of the polymer chains can be greatly affected by the rigidity of the polymer backbone.…”