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

Blazej Podlesny,Prakrit V Jena,Gregory Ghahramani,Zvi Yaari,Barbara Olszewska,Dawid Janas,Ron Feiner,Daniel A Heller

doi:10.1038/s41598-021-89839-4

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.

Highlights

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 present efforts to effect single-step purification of individual SWCNT chiralities, and techniques to monitor this separation by high-throughput photoluminescence spectroscopy
We demonstrated that the resolution and the facility of the aqueous two-phase extraction (ATPE) method for separation of surfactant-dispersed SWCNTs can be notably increased upon the introduction of a non-ionic tri-block copolymer surfactant into the system

Summary

Introduction

Chirality purification of single-walled carbon nanotubes (SWCNTs) is desirable for applications in many fields, but general utility is currently hampered by low throughput. Optical characterization of two parent materials selected for the study, EG150x and [6,5]-enriched CoMoCAT preparations, by 2D PLE mapping and absorption spectroscopy, revealed the presence of multiple CNT types (Fig. 1). 2D PLE maps of SC-dispersed, [6,5]-enriched SWCNTs sorted by ATPE upon varying the added volume of Pluronic.

Results

Conclusion