Self-Sorting of 10-µm-Long Single-Walled Carbon Nanotubes in Aqueous Solution

Peng Wang; Benjamin Barnes; Xiaojian Wu; Haoran Qu; Chiyu Zhang; Yang Shi; Robert J Headrick; Matteo Pasquali; YuHuang Wang

doi:10.1002/adma.201901641

Self-Sorting of 10-µm-Long Single-Walled Carbon Nanotubes in Aqueous Solution

Adv Mater. 2019 Aug;31(33):e1901641. doi: 10.1002/adma.201901641. Epub 2019 Jun 20.

Authors

Peng Wang¹, Benjamin Barnes^{1

2}, Xiaojian Wu¹, Haoran Qu¹, Chiyu Zhang¹, Yang Shi¹, Robert J Headrick³, Matteo Pasquali³, YuHuang Wang^{1

4}

Affiliations

¹ Department of Chemistry and Biochemistry, University of Maryland, 8051 Regents Drive, College Park, MD, 20742, USA.
² Department of Materials Science and Engineering, University of Maryland, 4418 Stadium Drive, College Park, MD, 20742, USA.
³ Department of Chemical and Biomolecular Engineering and Department of Chemistry, Rice University, 6100 Main Street, Houston, TX, 77005-1892, USA.
⁴ Maryland NanoCenter, University of Maryland, College Park, MD, 20742, USA.

Abstract

Single-walled carbon nanotubes (SWCNTs) are a class of 1D nanomaterials that exhibit extraordinary electrical and optical properties. However, many of their fundamental studies and practical applications are stymied by sample polydispersity. SWCNTs are synthesized in bulk with broad structural (chirality) and geometrical (length and diameter) distributions; problematically, all known post-synthetic sorting methods rely on ultrasonication, which cuts SWCNTs into short segments (typically <1 µm). It is demonstrated that ultralong (>10 µm) SWCNTs can be efficiently separated from shorter ones through a solution-phase "self-sorting". It is shown that thin-film transistors fabricated from long semiconducting SWCNTs exhibit a carrier mobility as high as ≈90 cm² V^-1 s^-1 , which is ≈10 times higher than those which use shorter counterparts and well exceeds other known materials such as organic semiconducting polymers (<1 cm² V^-1 s^-1 ), amorphous silicon (≈1 cm² V^-1 s^-1 ), and nanocrystalline silicon (≈50 cm² V^-1 s^-1 ). Mechanistic studies suggest that this self-sorting is driven by the length-dependent solution phase behavior of rigid rods. This length sorting technique shows a path to attain long-sought ultralong, electronically pure carbon nanotube materials through scalable solution processing.

Keywords: carrier mobility; nanomaterials processing; phase behavior; superacid-surfactant exchange; thin-film transistors; ultralong carbon nanotubes.

Abstract

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