Rice researchers unveil ‘shocking’ breakthrough in carbon nanotube recycling
by Alexandra Becker for Rice Information
Houston TX (SPX) Jan 14, 2025
In a major step towards making a sustainable and round economic system, Rice College researchers have printed a landmark examine within the journal Carbon demonstrating that carbon nanotube (CNT) fibers may be totally recycled with none loss of their construction or properties. This discovery positions CNT fibers as a sustainable various to conventional supplies like metals, polymers and the a lot bigger carbon fibers, that are notoriously tough to recycle.
“Recycling has lengthy been a problem within the supplies business – metals recycling is commonly inefficient and vitality intensive, polymers are likely to lose their properties after reprocessing and carbon fibers can’t be recycled in any respect, solely downcycled by chopping them up into quick items,” stated corresponding writer Matteo Pasquali, director of Rice’s Carbon Hub and the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, Supplies Science and NanoEngineering and Chemistry. “As CNT fibers are being scaled up, we requested whether or not and the way these new supplies could possibly be recycled sooner or later in order to proactively keep away from waste administration issues that emerged as different engineered supplies reached large-scale use. We anticipated that recycling could be tough and would result in vital lack of properties. Surprisingly, we discovered that carbon nanotube fibers far exceed the recyclability potential of present engineered supplies, providing an answer to a significant environmental problem.”
The analysis staff used solution-spun CNT fibers created by dissolving fiber-grade business CNTs in chlorosulfonic acid, a broadly used industrial solvent. As a result of end-of-life recycling invariably brings collectively supplies that have been manufactured by completely different corporations in numerous processes, it was necessary to evaluate the impact of a number of materials sources on the fiber manufacturing course of and fiber properties. Fibers constructed from various kinds of CNTs produced by completely different producers have been initially processed into separate single-source virgin fibers, then recycled by combining them and mixing in chlorosulfonic acid. Surprisingly, mixing the 2 fibers led to finish redissolution and no signal of separation of the 2 supply supplies into completely different liquid phases. This redissolved materials was spun right into a mixed-source recycled fiber that retained the identical construction and alignment of the virgin fiber.
“Through the use of two completely different sources of carbon nanotubes, we ensured that our recycling course of was consultant of real-life situations,” stated co-first writer Michelle Duran-Chaves, a graduate pupil in chemistry. “Remarkably, the recycled fibers demonstrated equal mechanical power, electrical conductivity, thermal conductivity and alignment, which is unprecedented within the discipline of engineered supplies.”
The analysis revealed a number of vital findings that place CNT fibers as a promising materials within the journey towards sustainable practices. Foremost amongst these is the total recyclability of CNT fibers. In contrast to conventional supplies, significantly polymers and carbon fibers that degrade in high quality throughout recycling, CNT fibers retained 100% of their authentic properties after being recycled.
“This preservation of high quality means CNT fibers can be utilized and reused in demanding functions with out compromising efficiency, thus extending their lifecycle and lowering the necessity for brand spanking new uncooked supplies,” stated co-first writer Ivan R. Siqueira, a current doctoral graduate in Rice’s Division of Chemical and Biomolecular Engineering who’s now affiliate professor of mechanical engineering on the Pontificia Universidade Catolica in Rio de Janeiro.
Equally vital is the effectivity of the recycling course of. The researchers demonstrated that CNT fiber recycling is notably extra environment friendly than conventional recycling strategies for metals and polymers, which frequently contain excessive vitality use, hazardous chemical compounds or labor-intensive sorting. CNT fibers, nonetheless, may be recycled with out sorting as fibers from varied sources may be mixed to supply high-quality recycled supplies. As soon as these supplies attain scale, this easy recycling course of will considerably cut back waste, vitality consumption and carbon dioxide emissions related to supplies manufacturing.
“The flexibility to completely recycle CNT fibers has broad implications for industries like aerospace, automotive and electronics,” Duran-Chaves stated. “We hope this might pave the way in which for totally recyclable composites in plane, autos, civil infrastructures and extra, in the end lowering environmental impacts throughout a variety of sectors.”
Different co-authors of the paper embody Rice graduate alumni Oliver Dewey, now of DexMat; Steven Williams; Cedric Ginestra, now of LyondellBasell; Yingru Tune, now a postdoctoral fellow at Purdue College; Rice undergraduate alumnus Juan De La Garza, now of Axiom Area; and Geoff Wehmeyer, assistant professor of mechanical engineering.
This analysis is a part of the broader program of the Carbon Hub, a Rice-led initiative growing a zero emissions future, the place superior carbon supplies and clear hydrogen are co-produced effectively and sustainably from hydrocarbons.
The work was supported by the Division of Vitality’s Superior Analysis Challenge Company, the Air Pressure Workplace of Scientific Analysis, the Robert A. Welch Basis, the Nationwide Science Basis, the Novo Nordisk Basis CO2 Analysis Heart, the Ken Kennedy Institute Graduate Fellowship from Schlumberger and Rice and a Riki Kobayashi Fellowship from Rice’s chemical and biomolecular engineering division.
Analysis Report:Totally recyclable carbon nanotube fibers
Associated Hyperlinks
Carbon Hub
Carbon Worlds – the place graphite, diamond, amorphous, fullerenes meet
