Speaker
Description
Single-walled carbon nanotubes (SWCNTs) are one-dimensional nanomaterials with exceptional electrical, thermal, mechanical, and optical properties. Despite their great potential in diverse nanotechnology applications, as-synthesized SWCNTs are inherently bundled because of strong vdW interactions. Consequently, their highly regarded properties are greatly compromised. Many applications of SWCNTs, such as transparent conducting films, require the manipulation of liquid-phase dispersions with high weight fractions of individual nanotubes or small bundles. Attaining uniformly dispersed SWCNT network remains a substantial hurdle. Although chemical functionalization and ultrasonication can facilitate individualization, they often come at the expense of the structural integrity and intrinsic electronic properties of the processed SWCNTs. In this work, we present a novel charge mediated individualization and stabilization of SWCNTs in water using a secondary bile salt sodium deoxycholate (DOC) as a surfactant. First, a potassium salt of SWCNTs of the form KC25 was dissolved in dimethyl sulfoxide (DMSO) to generate an individualized, negatively charged nanotube (nanotubide) solution. This solution was then stabilized in an aqueous solution of DOC. This step enabled us to produce a concentrated, long-lived dispersion of full-length SWCNTs in water. Absorption spectroscopy confirms the individualization and non-functionalization as absorption bands corresponding to excitonic transitions associated with mirrored van Hove singularities. The resulting transparent conducting films fabricated using full-length SWCNTs are 1 order of magnitude more conductive than those from the ultrasonicated shortened SWCNTs at equal transmittance. The individualization of SWCNTs using reductive chemistry and subsequent stabilization in aqueous DOC solution demonstrates an effective processing strategy for producing highly purified full-length SWCNTs suitable for advanced electronic applications.
| Keyword-1 | Individualization |
|---|---|
| Keyword-2 | Full-length SWCNTs |
| Keyword-3 | Transparent conducting films |