(410b) Separations and Measurements of Single-Wall Carbon Nanotube Enantiomers

Aqueous two-phase extraction (ATPE) is a widely used technique for separating sub-populations of specific (n,m) structures of single-wall carbon nanotubes (SWCNTs) from synthetic mixtures through scalable, liquid-phase, processing. Most commonly, the partitioning of different (n,m) SWCNT structures is controlled by the competition of two or more surfactants for the nanotube surface. Since at least one of the surfactants is typically a chiral molecule, this competition for the nanotube surface, and the resulting partitioning of a SWCNT species has long been understood to be SWCNT (n,m) handedness dependent. However, the exact interplay and effects of different handed surfactants and validation of the surface competition model has not been directly demonstrated. Using a recently developed method for rapidly determining the surfactant concentrations necessary for extraction for specific (n,m)/(m,n) species of SWCNTs using NIR fluorescence spectroscopy, along with analytical ultracentrifugation (AUC) data on separated populations, I will present data characterizing specific (n,m) handedness isolation of multiple nanotube structures. The interpretation of these results provides values for isolating single handed (n,m) structures, and validates the surfactant surface competition model for surfactant-ATPE.