Aqueous two-phase extraction of single-walled carbon nanotubes using nonionic surfactant Tween 60

Abstract

<p indent="0mm">Due to its excellent electronic and optical properties, single-walled carbon nanotubes (SWNTs) have attracted extensive attention. Since the property of SWNTs is determined by their structures, applications like high-performance devices require SWNTs with identical structures and uniform properties. Therefore, the sorting of SWNTs is of great significance. Aqueous two-phase (ATP) extraction is an emerging method that can be utilized to realize the structure sorting of SWNTs. ATP extraction is a repeatable and reliable technique that does not require state-of-the-art equipment. It is efficient and easy to scale up. In this article, by adjusting the concentration of sodium deoxycholate (DOC) and nonionic surfactant Tween 60, the diameter sorting of SWNTs and the separation of high purity (6,5) tubes were achieved. The sorting can be carried out at a higher DOC concentration, which could improve the competitive coating between DOC and Tween 60 on the surface of SWNTs, and further improve the sorting efficiency of the co-surfactant system. The comparison of the separation results between the Tween 60-DOC surfactant system and the SDS-DOC surfactant system shows that the introduction of nonionic surfactant Tween 60 is beneficial to the separation of higher purity (6,5) tubes.