Purification of dense carbon nanotube networks by subcritical hydrothermal processing
Carbon nanotube (CNT)-reinforced composites are promising materials for high-performance, lightweight structures; however, homogeneous infiltration of CNTs by a matrix material is necessary to achieve desired mechanical properties. Critical to overcoming this challenge at scale is purification of CN...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Elsevier BV
2023
|
| Online Access: | https://hdl.handle.net/1721.1/153054 |
| _version_ | 1811082553171378176 |
|---|---|
| author | Durso, Michael N. Hart, A. John |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Durso, Michael N. Hart, A. John |
| author_sort | Durso, Michael N. |
| collection | MIT |
| description | Carbon nanotube (CNT)-reinforced composites are promising materials for high-performance, lightweight structures; however, homogeneous infiltration of CNTs by a matrix material is necessary to achieve desired mechanical properties. Critical to overcoming this challenge at scale is purification of CNT materials produced by floating-catalyst chemical vapor deposition. Here, we present a hydrothermal processing technique for purification of CNT yarns, wherein as-received material is exposed to superheated, subcritical water in a hydrothermal reactor. This process selectively removes amorphous carbon and acid impurities while preserving the yarn structure. We find this technique to be consistent and tunable, with processing time directly correlating to linear density reduction up to a saturation limit. Using commerciallyavailable yarns, we find that after 4 h of treatment at 200 °C, the weight loss of the yarn under inert atmosphere is reduced from 12% to 5%, the atomic percentage of oxygen at the surface by 42%, and the ID/IG by 30%. In addition, the yarn specific strength (1.3 N/tex) is preserved, while the specific Young’s modulus is significantly increased by 20% (79 to 95 N/tex). At longer treatment times, we obtain greater purity and higher specific Young’s modulus, but at a substantial reduction in tensile strength, which we hypothesize results from eliminating amorphous carbon toughening CNT bundles. The reported method could be scaled to continuous processing in tandem with post-purification treatments, and appears broadly applicable to different continuous CNT networks. |
| first_indexed | 2024-09-23T12:04:54Z |
| format | Article |
| id | mit-1721.1/153054 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T12:04:54Z |
| publishDate | 2023 |
| publisher | Elsevier BV |
| record_format | dspace |
| spelling | mit-1721.1/1530542024-01-24T18:32:49Z Purification of dense carbon nanotube networks by subcritical hydrothermal processing Durso, Michael N. Hart, A. John Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Mechanical Engineering Carbon nanotube (CNT)-reinforced composites are promising materials for high-performance, lightweight structures; however, homogeneous infiltration of CNTs by a matrix material is necessary to achieve desired mechanical properties. Critical to overcoming this challenge at scale is purification of CNT materials produced by floating-catalyst chemical vapor deposition. Here, we present a hydrothermal processing technique for purification of CNT yarns, wherein as-received material is exposed to superheated, subcritical water in a hydrothermal reactor. This process selectively removes amorphous carbon and acid impurities while preserving the yarn structure. We find this technique to be consistent and tunable, with processing time directly correlating to linear density reduction up to a saturation limit. Using commerciallyavailable yarns, we find that after 4 h of treatment at 200 °C, the weight loss of the yarn under inert atmosphere is reduced from 12% to 5%, the atomic percentage of oxygen at the surface by 42%, and the ID/IG by 30%. In addition, the yarn specific strength (1.3 N/tex) is preserved, while the specific Young’s modulus is significantly increased by 20% (79 to 95 N/tex). At longer treatment times, we obtain greater purity and higher specific Young’s modulus, but at a substantial reduction in tensile strength, which we hypothesize results from eliminating amorphous carbon toughening CNT bundles. The reported method could be scaled to continuous processing in tandem with post-purification treatments, and appears broadly applicable to different continuous CNT networks. 2023-11-27T19:27:33Z 2023-11-27T19:27:33Z 2022-10 2023-11-27T19:08:29Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/153054 Durso, Michael N. and Hart, A. John. 2022. "Purification of dense carbon nanotube networks by subcritical hydrothermal processing." Carbon Trends, 9. en 10.1016/j.cartre.2022.100206 Carbon Trends Creative Commons Attribution Noncommercial No Derivatives http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier BV Elsevier BV |
| spellingShingle | Durso, Michael N. Hart, A. John Purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| title | Purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| title_full | Purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| title_fullStr | Purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| title_full_unstemmed | Purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| title_short | Purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| title_sort | purification of dense carbon nanotube networks by subcritical hydrothermal processing |
| url | https://hdl.handle.net/1721.1/153054 |
| work_keys_str_mv | AT dursomichaeln purificationofdensecarbonnanotubenetworksbysubcriticalhydrothermalprocessing AT hartajohn purificationofdensecarbonnanotubenetworksbysubcriticalhydrothermalprocessing |