Polymer sorting of single-walled carbon nanotubes : additives and applications
Abstract/Contents
- Abstract
- Single-walled carbon nanotubes (CNTs) are a promising candidate for flexible and wearable electronics, offering robust mechanical properties, solution-processability as well as superlative charge carrier mobilities. However, bulk synthesis of CNTs produces a mixture of metallic and semiconducting species, greatly limiting their technological utility. To address this issue, various post-synthesis purification schemes have been investigated. Polymer sorting in particular has emerged as a scalable and accessible solution to this problem, offering fast processing times of 1-2 hours, yields over 20% and semiconducting purities as high as 99.99%. Despite these encouraging developments, there is still much to be desired from this strategy, including greater mechanistic insight, higher yields and purities, chiral selectivity, and reducing the polymer's effect on CNT device performance, among others. This thesis discusses the role of additives on polymer sorting of CNTs. First, I will describe the importance of polymer recyclability to the scalability of the sorting process, and introduce a recyclable, 2-ureido-4-pyrimidinone-based supramolecular polymer. I will then show that the molecular weight and conformation of this polymer can be tuned by the addition of monofunctional chain stoppers, enabling improvements in sorting yields without compromising the purity or properties of sorted CNTs. Next, I will recount the mechanistic principles underlying polymer sorting, and examine the effects of polar cosolvents in the context of the polarizability hypothesis of CNT sorting. Finally, I will present a cosolvent-based flocculation technique for reducing the amount of excess sorting polymer in polymer-sorted CNT dispersions. This method can be used to improve the mobility and on-off ratio of CNT thin-film transistors regardless of the choice of sorting polymer, and also leads to enhanced process compatibility and versatility, facilitating the fabrication of stretchable, all-inkjet-printed CNT transistor arrays. Taken together, these forays demonstrate the importance of additives to the polymer sorting process, both in terms of sorting efficacy as well as the performance of resulting CNT devices.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Gao, Theodore Zhenyu |
|---|---|
| Degree supervisor | Bao, Zhenan |
| Degree supervisor | Hong, Guosong |
| Thesis advisor | Bao, Zhenan |
| Thesis advisor | Hong, Guosong |
| Thesis advisor | Mannix, Andrew |
| Degree committee member | Mannix, Andrew |
| Associated with | Stanford University, Department of Materials Science and Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Theodore Z. Gao. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/ry198sd8464 |
Access conditions
- Copyright
- © 2021 by Theodore Zhenyu Gao
- License
- This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).
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