Enrichment of Armchair Carbon Nanotubes via Density Gradient Ultracentrifugation: Raman Spectroscopy Evidence

TL;DR

This study demonstrates that density gradient ultracentrifugation effectively enriches armchair and near-armchair metallic carbon nanotubes, with Raman spectroscopy confirming a majority presence in the samples.

Contribution

It provides experimental evidence that ultracentrifugation can selectively enrich armchair carbon nanotubes, enhancing their relative abundance in samples.

Findings

Armchair nanotubes constitute over 50% of each (2n + m) family.

Density gradient ultracentrifugation enriches metallic nanotubes.

Raman spectroscopy confirms enrichment of armchair species.

Abstract

We have used resonant Raman scattering spectroscopy to fully analyze the relative abundances of different (n,m) species in single-walled carbon nanotube samples that are metallically enriched by density gradient ultracentrifugation. Strikingly, the data clearly show that our density gradient ultracentrifugation process enriches the metallic fractions in armchair and near-armchair species. We observe that armchair carbon nanotubes constitute more than 50% of each (2n + m) family.