Nanotubes can grow on graphite (top) in an unruly mass (middle) according to "space's recipe." The overlapping segments on a single nanotube (bottom) are a telltale sign of the cup-stacked structure. (Image on bottom reproduced from Astrophysical Journal Letters.)
Space apparently has its own recipe for making carbon nanotubes, one of the most intriguing contributions of nanotechnology here on Earth, and metals are conspicuously missing from the list of ingredients.
The finding is the surprising by-product of lab experiments designed by Joseph Nuth at NASA’s Goddard Space Flight Center, Greenbelt, Md. and his colleagues to address the astronomical question of how carbon gets recycled in the regions of space that spawn stars and planets. The work also could help researchers understand puzzling observations about some supernovas.
In a recent paper in Astrophysical Journal Letters, Nuth’s team describes the modest chemical reaction. Unlike current methods for producing carbon nanotubes—tiny yet strong structures with a range of applications in electronics and, ultimately, perhaps even medicine—the new approach does not need the aid of a metal catalyst. "Instead, nanotubes were produced when graphite dust particles were exposed to a mixture of carbon monoxide and hydrogen gases," explains Nuth.
"I am amazed at the implications of this paper, not only for astrophysics but also for materials science," says Dick Zare, the chair of the chemistry department at Stanford University, Stanford, Calif. "Could Nature know a new chemistry for making carbon nanotubes that we have yet to discover?"
The finding is the surprising by-product of lab experiments designed by Joseph Nuth at NASA’s Goddard Space Flight Center, Greenbelt, Md. and his colleagues to address the astronomical question of how carbon gets recycled in the regions of space that spawn stars and planets. The work also could help researchers understand puzzling observations about some supernovas.
In a recent paper in Astrophysical Journal Letters, Nuth’s team describes the modest chemical reaction. Unlike current methods for producing carbon nanotubes—tiny yet strong structures with a range of applications in electronics and, ultimately, perhaps even medicine—the new approach does not need the aid of a metal catalyst. "Instead, nanotubes were produced when graphite dust particles were exposed to a mixture of carbon monoxide and hydrogen gases," explains Nuth.
"I am amazed at the implications of this paper, not only for astrophysics but also for materials science," says Dick Zare, the chair of the chemistry department at Stanford University, Stanford, Calif. "Could Nature know a new chemistry for making carbon nanotubes that we have yet to discover?"
One indication of that possibility came in 2008, when the long, thin carbon structures known as graphite whiskers—essentially, bigger cousins of carbon nanotubes—were identified in three meteorites. That finding offered the tantalizing prospect that a haze of graphite whiskers in space could explain why some supernovas appear dimmer, and therefore farther away, than they should be, according to current models. Yet, "very little is known about graphite whisker formation, and so it is difficult to adequately interpret their discovery," says Marc Fries of NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
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