Rice College researchers printed a examine within the journal Carbon, demonstrating that carbon nanotube (CNT) fibers might 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 different to conventional supplies similar 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 may very well 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 troublesome and would result in vital lack of properties. Surprisingly, we discovered that carbon nanotube fibers far exceed the recyclability potential of current engineered supplies, providing an answer to a serious environmental difficulty.”
Utilizing chlorosulfonic acid, a typical industrial solvent, the staff dissolved fiber-grade industrial CNTs to supply solution-spun CNT fibers. Evaluating the impression of various materials sources on the fiber manufacturing course of and fiber properties was vital, as end-of-life recycling usually includes combining supplies from varied producers utilizing totally different manufacturing strategies.
Fibers made out of several types of CNTs from varied producers had 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.
Through the use of two totally different sources of carbon nanotubes, we ensured that our recycling course of was consultant of real-life circumstances. Remarkably, the recycled fibers demonstrated equal mechanical energy, electrical conductivity, thermal conductivity and alignment, which is unprecedented within the area of engineered supplies.
Michelle Durán-Chaves, Examine Co-First Writer and Graduate Pupil, 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. In contrast to conventional supplies similar to polymers and carbon fibers, which degrade in high quality throughout recycling, CNT fibers retain 100 % of their unique 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 lowering the necessity for brand new uncooked supplies.
Ivan R. Siqueira, Examine Co-First Writer and Affiliate Professor, Pontifícia Universidade Católica
The effectivity of the recycling course of is one other vital benefit. The researchers noticed that CNT fiber recycling is way extra environment friendly than standard steel and polymer recycling strategies, which frequently contain excessive vitality consumption, hazardous chemical compounds, or labor-intensive sorting.
In distinction, CNT fibers might be recycled with out sorting, as fibers from varied sources might be mixed to supply high-quality recycled supplies. At scale, this simple recycling course of may considerably scale back waste, vitality use, and carbon dioxide emissions related to manufacturing.
Durán-Chaves added, “The flexibility to completely recycle CNT fibers has broad implications for industries like aerospace, automotive, and electronics. We hope this might pave the best way for absolutely recyclable composites in plane, autos, civil infrastructures, and extra, in the end lowering 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 Music, at present a postdoctoral fellow at Purdue College; Rice undergraduate alumnus Juan De La Garza, now with Axiom House; 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 Vitality’s Superior Analysis Mission Company, the Air Pressure 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 approach 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
