Rice researchers unveil ‘stunning’ 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 revealed a landmark research within the journal Carbon demonstrating that carbon nanotube (CNT) fibers might be totally recycled with none loss of their construction or properties. This discovery positions CNT fibers as a sustainable different to conventional supplies like metals, polymers and the a lot bigger carbon fibers, that are notoriously troublesome to recycle.
“Recycling has lengthy been a problem within the supplies trade – metals recycling is commonly inefficient and vitality intensive, polymers are inclined 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,” mentioned 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 might 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 can be troublesome and would result in important lack of properties. Surprisingly, we discovered that carbon nanotube fibers far exceed the recyclability potential of current engineered supplies, providing an answer to a significant environmental situation.”
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 several processes, it was vital to evaluate the impact of a number of materials sources on the fiber manufacturing course of and fiber properties. Fibers comprised of 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.
“By utilizing two completely different sources of carbon nanotubes, we ensured that our recycling course of was consultant of real-life circumstances,” mentioned co-first writer Michelle Duran-Chaves, a graduate scholar 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 important 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, notably 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 purposes with out compromising efficiency, thus extending their lifecycle and decreasing the necessity for brand new uncooked supplies,” mentioned co-first writer Ivan R. Siqueira, a latest 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 important 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 regularly contain excessive vitality use, hazardous chemical substances or labor-intensive sorting. CNT fibers, nonetheless, might be recycled with out sorting as fibers from varied sources might be mixed to supply high-quality recycled supplies. As soon as these supplies attain scale, this straightforward recycling course of will considerably cut back waste, vitality consumption and carbon dioxide emissions related to supplies manufacturing.
“The power to totally recycle CNT fibers has broad implications for industries like aerospace, automotive and electronics,” Duran-Chaves mentioned. “We hope this might pave the best way for totally recyclable composites in plane, autos, civil infrastructures and extra, finally decreasing 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 House; 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 Undertaking Company, the Air Power 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:Absolutely recyclable carbon nanotube fibers
Associated Hyperlinks
Carbon Hub
Carbon Worlds – the place graphite, diamond, amorphous, fullerenes meet
