Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting
Semiconducting (semi-) single-walled carbon nanotubes (SWNTs) must be purified of their metallic (met-) counterparts for most applications including nanoelectronics, solar cells, chemical sensors, and artificial skins. Previous bulk sorting techniques are based on subtle contrasts between properties...
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sg-ntu-dr.10356-834292023-12-29T06:47:19Z Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting Wang, Jing Nguyen, Tuan Dat Cao, Qing Wang, Yilei Tan, Marcus Y.C. Chan-Park, Mary B. School of Chemical and Biomedical Engineering Carbon nanotubes Gel chromatography Semiconducting (semi-) single-walled carbon nanotubes (SWNTs) must be purified of their metallic (met-) counterparts for most applications including nanoelectronics, solar cells, chemical sensors, and artificial skins. Previous bulk sorting techniques are based on subtle contrasts between properties of different nanotube/dispersing agent complexes. We report here a method which directly exploits the nanotube band structure differences. For the heterogeneous redox reaction of SWNTs with oxygen/water couple, the aqueous pH can be tuned so that the redox kinetics is determined by the availability of nanotube electrons only at/near the Fermi level, as predicted quantitatively by the Marcus–Gerischer (MG) theory. Consequently, met-SWNTs oxidize much faster than semi-SWNTs and only met-SWNTs selectively reverse the sign of their measured surface zeta potential from negative to positive at the optimized acidic pH when suspended with nonionic surfactants. By passing the redox-reacted nanotubes through anionic hydrogel beads, we isolate semi-SWNTs to record high electrically verified purity above 99.94% ± 0.04%. This facile charge sign reversal (CSR)-based sorting technique is robust and can sort SWNTs with a broad diameter range. NMRC (Natl Medical Research Council, S’pore) Accepted version 2016-09-06T06:35:37Z 2019-12-06T15:22:28Z 2016-09-06T06:35:37Z 2019-12-06T15:22:28Z 2016 Journal Article Wang, J., Nguyen, T. D., Cao, Q., Wang, Y., Tan, M. Y., & Chan-Park, M. B. (2016). Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting. ACS Nano, 10(3), 3222-3232. 1936-0851 https://hdl.handle.net/10356/83429 http://hdl.handle.net/10220/41423 10.1021/acsnano.5b05795 en ACS Nano © 2016 American Chemical Society. This is the author created version of a work that has been peer reviewed and accepted for publication by ACS Nano, American Chemical Society. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1021/acsnano.5b05795]. 43 p. application/pdf application/pdf |
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Carbon nanotubes Gel chromatography Wang, Jing Nguyen, Tuan Dat Cao, Qing Wang, Yilei Tan, Marcus Y.C. Chan-Park, Mary B. Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting |
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Semiconducting (semi-) single-walled carbon nanotubes (SWNTs) must be purified of their metallic (met-) counterparts for most applications including nanoelectronics, solar cells, chemical sensors, and artificial skins. Previous bulk sorting techniques are based on subtle contrasts between properties of different nanotube/dispersing agent complexes. We report here a method which directly exploits the nanotube band structure differences. For the heterogeneous redox reaction of SWNTs with oxygen/water couple, the aqueous pH can be tuned so that the redox kinetics is determined by the availability of nanotube electrons only at/near the Fermi level, as predicted quantitatively by the Marcus–Gerischer (MG) theory. Consequently, met-SWNTs oxidize much faster than semi-SWNTs and only met-SWNTs selectively reverse the sign of their measured surface zeta potential from negative to positive at the optimized acidic pH when suspended with nonionic surfactants. By passing the redox-reacted nanotubes through anionic hydrogel beads, we isolate semi-SWNTs to record high electrically verified purity above 99.94% ± 0.04%. This facile charge sign reversal (CSR)-based sorting technique is robust and can sort SWNTs with a broad diameter range. |
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School of Chemical and Biomedical Engineering |
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School of Chemical and Biomedical Engineering Wang, Jing Nguyen, Tuan Dat Cao, Qing Wang, Yilei Tan, Marcus Y.C. Chan-Park, Mary B. |
format |
Article |
author |
Wang, Jing Nguyen, Tuan Dat Cao, Qing Wang, Yilei Tan, Marcus Y.C. Chan-Park, Mary B. |
author_sort |
Wang, Jing |
title |
Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting |
title_short |
Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting |
title_full |
Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting |
title_fullStr |
Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting |
title_full_unstemmed |
Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting |
title_sort |
selective surface charge sign reversal on metallic carbon nanotubes for facile ultrahigh purity nanotube sorting |
publishDate |
2016 |
url |
https://hdl.handle.net/10356/83429 http://hdl.handle.net/10220/41423 |
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1787136516294705152 |