(Invited) Purification Using Atpe to Single (n,m) Species in the Large Diameter Single-Wall Carbon Nanotube Limit

Abstract

Separation of single-wall carbon nanotube (SWCNT) populations to completely specified physical structures is a primary milestone necessary for enabling SWCNT-based technologies. Aqueous two-phase extraction (ATPE), in which the spontaneous phase separation of an aqueous polymer mixture is utilized to spatially separate solutes on the basis of their chemical potential difference for the two phases, is a promising technology for achieving this milestone. However, due to the expanded number of (n,m) species with increasing nanotube diameter, and the increased difficulty in optical characterization of aqueous-dispersed samples, isolation of larger diameter SWCNTs, > ~1.4 nm in diameter, has continued to be a difficult proposition. Advances in methodology of separation and sample preparation are now overcoming both these barriers in our laboratories. In this work I will detail improved separation procedures utilizing alkane-filled SWCNT populations for the isolation of individual SWCNT (n,m) structures from > 1.5 nm average diameter SWCNT dispersions. These method developments can readily isolate multiple large diameter (n,m) species, and are enabling new scientific and device application work. The enhanced separation methods, isolated (n,m) species, and applications of those populations will be presented.