Encapsulation and polymerization of acetylene molecules inside a carbon nanotube

TL;DR

This study investigates the energetics and potential polymerization of acetylene molecules inside carbon nanotubes using ab initio calculations, proposing a method to produce encapsulated polyacetylene chains for electronic applications.

Contribution

It provides the first ab initio analysis of acetylene encapsulation and polymerization inside carbon nanotubes, suggesting a new method for synthesizing molecular electronic components.

Findings

Encapsulation energy of C2H2 inside CNT calculated.

No activation barrier for polymerization of C2H2 inside CNT.

Potential to produce isolated polyacetylene chains for electronics.

Abstract

We study the energetics of acetylene (${\rm C_2H_2}$) molecules inside a carbon nanotube (CNT) using the {\it ab initio} pseudopotential method. The encapsulation energy of a single ${\rm C_2H_2}$ molecule into the nanotube and the formation energy of ${\rm (C_2H_2)}_n$@CNT are calculated. We investigate whether a polyacetylene chain can be produced by fusion of the close-packed acetylene molecules inside the CNT and find that there is practically no activation barrier to polymerization. We propose to employ this method to obtain straight, perfectly isolated, and single-stranded polyacetylene chains encapsulated inside CNTs, which may be used for molecular electronic devices.