(739b) High-Fidelity Single Column Separation of Single Walled Carbon Nanotubes Using Agarose Gel

For their inclusion in novel electronic devices, the post synthesis separation of single walled carbon nanotubes (SWCNTs) is of great interest.  While several methods have been utilized to achieve these separations with various levels in purity, the most promising technique to produce large-scale separations is the selective adsorption of SWCNTs onto an agarose gel stationary phase.  Recently, several researchers have reported successful modification to the process in order to achieve further separation of the semiconducting fractions by (n,m) type.  While these changes are a significant step in SWCNT processing, they are difficult for development on an industrial scale due to the use of harsh chemical treatments (pH adjustments) and temperature gradients that may be difficult to control. In addition, many of these approaches require multiple columns in series, causing substantial dilution of the collected fractions, which increases the amount of surfactant required and may require the fractions to be concentrated before use.  Here we report a method for both type and chirality separations of sodium dodecyl sulfate (SDS) suspended SWCNTS at a single temperature.  Using our understanding of the mechanism behind selective adsorption of SWCNTs onto agarose, we have developed high-fidelity separations based on a single elution profile in a single column. The results confirm that the surfactant orientation on the SWCNT surface is an important parameter that affects selective adsorption during separation.  The design of a simple, single-column technique to separate SWCNTs by (n,m) type is a major step in realizing their full potential.