@article{Green2009, 
author = {Alexander A. Green and Matthew C. Duch and Mark C. Hersam},
title = {Isolation of Single-Walled Carbon Nanotube Enantiomers by Density Differentiation},
year = {2009},
journal = {Nano Research},
volume = {2},
number = {1},
pages = {69-77},
keywords = {Carbon nanotube, chirality, separation, enantiomer, handedness, optical activity},
url = {https://www.sciopen.com/article/10.1007/s12274-009-9006-y},
doi = {10.1007/s12274-009-9006-y},
abstract = {Current methods of synthesizing single-walled carbon nanotubes (SWNTs) result in racemic mixtures that have impeded the study of left- and right-handed SWNTs. Here we present a method of isolating different SWNT enantiomers using density gradient ultracentrifugation. Enantiomer separation is enabled by the chiral surfactant sodium cholate, which discriminates between left- and right-handed SWNTs and thus induces subtle differences in their buoyant densities. This sorting strategy can be employed for simultaneous enrichment by handedness and roll-up vector of SWNTs having diameters ranging from 0.7 to 1.5 nm. In addition, circular dichroism of enantiomer refined samples enables identification of high-energy optical transitions in SWNTs.}
}