(220d) Quantified Carbon Nanotube (n,m) Separation Dependencies in Aqueous Two-Polymer Phase Extraction

Surfactant controlled aqueous two-polymer phase extraction is a scalable and sensitive method for separating specific (n,m) species of single-walled carbon nanotubes (SWCNTs) to the level of pure left- or right-handed enantiomers. The basis for the separation is progressive isolation of different SWCNT structures into top or bottom self-separating polymer phases until a single structure remains. The selecting mechanism for a top versus bottom phase extraction in a given separation depends sensitively on the type and chemistry of the adsorbed surfactant layer on each (n,m) species, and can be controlled by the choice of competing surfactant(s) and modulator chemicals. In this presentation I will describe the quantified extraction conditions and effects of multiple modulators, such as salts and 3^rd component surfactants, to the precise extraction conditions for different (n,m) SWCNTs as determined through high-precision fluorescence measurements. In addition to precise extraction condition data, the effects of surfactant concentration and modulator properties are yielding new mechanistic understanding to the competitive surfactant adsorption at the heart of ATPE separations.