Rice College researchers printed a examine within the journal Carbon, demonstrating that carbon nanotube (CNT) fibers could be recycled with out dropping their construction or properties, supporting efforts towards a extra sustainable and round economic system.
This discovering positions CNT fibers as a sustainable various to conventional supplies corresponding to metals, polymers, and bigger carbon fibers, that are difficult to recycle.
Recycling has lengthy been a problem within the supplies business—metals recycling is usually 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 brief items.
Matteo Pasquali, A.J. Hartsook Professor of Chemical and Biomolecular Engineering, Supplies Science and NanoEngineering and Chemistry, Rice College
He added, “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 tough 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 difficulty.”
Utilizing chlorosulfonic acid, a typical industrial solvent, the staff dissolved fiber-grade business CNTs to provide solution-spun CNT fibers. Evaluating the influence of various materials sources on the fiber manufacturing course of and fiber properties was necessary, as end-of-life recycling typically includes combining supplies from numerous producers utilizing completely different manufacturing strategies.
Fibers made out of various kinds of CNTs from numerous producers have been first processed into distinct single-source virgin fibers after which recycled by mixing them with chlorosulfonic acid. Notably, the 2 fibers absolutely redissolved with out separating into distinct liquid phases. The redissolved materials was spun right into a mixed-source recycled fiber with the identical construction and alignment because the virgin fiber.
By utilizing two completely different sources of carbon nanotubes, we ensured that our recycling course of was consultant of real-life situations. Remarkably, the recycled fibers demonstrated equal mechanical power, electrical conductivity, thermal conductivity and alignment, which is unprecedented within the discipline of engineered supplies.
Michelle Durán-Chaves, Research Co-First Creator and Graduate Scholar, Rice College
The examine recognized a number of key findings that spotlight CNT fibers as a viable materials for sustainable practices. Foremost amongst these is their full recyclability. Not like conventional supplies corresponding to polymers and carbon fibers, which degrade in high quality throughout recycling, CNT fibers retain 100 % of their authentic properties after recycling.
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 decreasing the necessity for brand new uncooked supplies.
Ivan R. Siqueira, Research Co-First Creator and Affiliate Professor, Pontifícia Universidade Católica
The effectivity of the recycling course of is one other important benefit. The researchers noticed that CNT fiber recycling is much extra environment friendly than standard metallic and polymer recycling strategies, which regularly contain excessive vitality consumption, hazardous chemical substances, or labor-intensive sorting.
In distinction, CNT fibers could be recycled with out sorting, as fibers from numerous sources could be mixed to provide high-quality recycled supplies. At scale, this easy recycling course of might considerably cut back waste, vitality use, and carbon dioxide emissions related to manufacturing.
Durán-Chaves added, “The power to totally recycle CNT fibers has broad implications for industries like aerospace, automotive, and electronics. We hope this might pave the way in which for absolutely recyclable composites in plane, automobiles, civil infrastructures, and extra, finally decreasing environmental impacts throughout a variety of sectors.”
The examine’s co-authors embody Rice graduate alumni Oliver Dewey, now with DexMat; Steven Williams; Cedric Ginestra, now with LyondellBasell; Yingru Tune, presently a postdoctoral fellow at Purdue College; Rice undergraduate alumnus Juan De La Garza, now with Axiom Area; and Geoff Wehmeyer, assistant professor of mechanical engineering at Rice.
This analysis is a part of the Carbon Hub, a Rice-led initiative aiming for a zero-emission future by effectively and sustainably co-producing superior carbon supplies and clear hydrogen from hydrocarbons.
The examine acquired funding from the Division of Power’s Superior Analysis Mission Company, the Air Power Workplace of Scientific Analysis, the Robert A. Welch Basis, the Nationwide Science Basis, the Novo Nordisk Basis CO2 Analysis Middle, the Ken Kennedy Institute Graduate Fellowship from Schlumberger and Rice, and the Riki Kobayashi Fellowship from Rice’s chemical and biomolecular engineering division.
Rice researchers unveil analysis in carbon nanotube recycling, paving means for sustainable supplies
Video Credit score: Rice College
Journal Reference:
Siqueira, I. R., et. al. (2024) Absolutely recyclable carbon nanotube fibers. Carbon. doi.org/10.1016/j.carbon.2024.119899
