En route to single-step, two-phase purification of carbon nanotubes facilitated by high-throughput spectroscopy

Abstract

Chirality purification of single-walled carbon nanotubes (SWCNTs) is desirable for applications in many fields, but general utility is currently hampered by low throughput. We discovered a method to obtain single-chirality SWCNT enrichment by the aqueous two-phase extraction (ATPE) method in a single step. To achieve appropriate resolution, a biphasic system of non-ionic tri-block copolymer surfactant is varied with an ionic surfactant. A nearly-monochiral fraction of SWCNTs can then be harvested from the top phase. We also found, via high-throughput, near-infrared excitation-emission photoluminescence spectroscopy, that the parameter space of ATPE can be mapped to probe the mechanics of the separation process. Finally, we found that optimized conditions can be used for sorting of SWCNTs wrapped with ssDNA as well. Elimination of the need for surfactant exchange and simplicity of the separation process make the approach promising for high-yield generation of purified single-chirality SWCNT preparations.

Prospects of Fluorescent Single-Chirality Carbon Nanotube-Based Biosensors

“…It represents a complex interplay of various parameters and components, and several studies elucidated this process. , The equipment for ATPE is inexpensive; the process is easy to perform and highly scalable. It is also fast due to a low number of steps in the separation (sometimes only one step for certain chiralities), , but extraction of more than one chirality is only sequentially possible . Yields of the extraction process are not always specified in the literature.…”

The role of the bile salt surfactant sodium deoxycholate in aqueous two-phase separation of single-wall carbon nanotubes revealed by systematic parameter variations

“…In recent works, Sims et al [32,42] proposed to therefore perform surfactant-exchange PL experiments inside the polymer matrices typically used in ATP, and spectroscopically detectable shifts in PL were assigned to possible transition points in ATP, thus providing a faster tool to estimate the relevant surfactant concentrations for ATP separation. More recently, this was confirmed by Podlesny et al, for the optimization of other surfactant systems [43].…”

Recent Advances in Structure Separation of Single‐Wall Carbon Nanotubes and Their Application in Optics, Electronics, and Optoelectronics

“…The simplified separation steps could achieve the separation of singlechirality SWCNTs, but the separable species was limited (Figure 16b). [282,283] Recently, Li et al further finely tuned the coating coverage of cosurfactants on different (n, m) SWCNTs by precisely controlling the pH of the SWCNT suspension, thus improving the chirality separation resolution (Figure 16c). [259] Through this approach, 11 kinds of single-chirality SWCNTs, including metallic SWCNTs, were successfully separated in no more than three steps (Figure 16d), [259] simplifying the ATP separation procedure and demonstrating the ATP-based largescale separation of single-chirality SWCNTs.…”

“…The simplified separation steps could achieve the separation of single‐chirality SWCNTs, but the separable species was limited (Figure 16b). [ 282,283 ] Recently, Li et al. further finely tuned the coating coverage of cosurfactants on different ( n , m ) SWCNTs by precisely controlling the pH of the SWCNT suspension, thus improving the chirality separation resolution (Figure 16c).…”