496 31 JANUARY 2020 • VOL 367 ISSUE 6477 sciencemag.org SCIENCEPHOTOS: (TOP TO BOTTOM) MARIJAN MURAT/PICTURE-ALLIANCE/DPA/AP IMAGES; JEFF FITLOW/RICE UNIVERSITYA
wonder material could soon become a
bulk commodity. Researchers at Rice
University report in Nature this week
that they can zap virtually any source
of solid carbon, from food scraps to
car tires, and turn it into graphene—
sheets of carbon atoms prized for use in
high-strength plastic and flexible electron-
ics. Current techniques yield tiny amounts of
picture-perfect graphene or up to tons of less-
prized graphene chunks; the new method
already produces grams per day of near-
pristine graphene in the lab, and researchers
are now scaling it up to kilograms per day.
“This work is pioneering from a scien-
tific and practical standpoint,” says Ray
Baughman, a chemist at the University
of Texas, Dallas, as it promises graphene
cheap enough to strengthen asphalt or
paint. “I wish I had thought of it.” Already
the Rice team has founded a company, Uni-
versal Matter, to commercialize the waste-
to-graphene process.
With atom-thin sheets of carbon atoms ar-
ranged like chicken wire, graphene is stron-
ger than steel, conducts electricity and heat
better than copper, and can serve as an im-
permeable barrier. But since its 2004 discov-
ery, high-quality graphene—in single sheets
or a few stacked layers—has remained expen-
sive to make and purify on an industrial scale.
That’s not a problem for making diminutive
devices such as transistors and light-emitting
diodes. But current techniques, which make
graphene by depositing it from a vapor, are
too costly for high-volume applications. And
higher throughput approaches, such as peel-
ing graphene from chunks of graphite, pro-
duce flecks composed of up to 50 graphene
layers that are not ideal for most applications.
In 2014, James Tour, a chemist at Rice,
and his colleagues found they could make
a more pure form of graphene—each piece
just a few layers thick—by zapping a form of
amorphous carbon called carbon black with a
laser. Brief pulses heated the carbon to more
than 3000 kelvins, snapping the bonds be-
tween carbon atoms. As the carbon cooled,
it coalesced into graphene. But the approach
used a lot of energy to make tiny quantities.
Then, Luong Xuan Duy, one of Tour’s
graduate students, read that other research-
ers had created metal nanoparticles by zap-
ping a material with electricity, creating
the same brief blast of heat as the laser. So
Duy put a dash of carbon black in a glass
vial and zapped it with 400 volts for up to
200 milliseconds. Initially he got junk. But
after tweaks, he saw a yellowish white flash,
indicating the temperature in the vial was
about 3000 kelvins. Chemical tests revealed
he had produced graphene.
It was a type of graphene ideal for bulk
uses: “turbostatic” graphene, with its layers
at all angles atop one another. “That’s a good
thing,” Duy says. In water or other solvents,
turbostatic graphene remains suspended
instead of clumping, allowing each fleck to
interact with the composite it’s added to.
“This will make it a very good material
for applications,” says Monica Craciun,
a materials physicist at the University of
Exeter. In 2018, she and her colleagues
reported that adding graphene to con-
crete more than doubled its compressive
strength. Tour’s team saw much the same
result. When it added just 0.05% by weight
of flash-produced graphene to concrete, the
compressive strength rose 25%; graphene
added to polydimethylsiloxane, a common
plastic, boosted its strength by 250%. Other
research suggests it can improve the dura-
bility of asphalt and paint.
These applications would require high-
quality graphene by the ton. Fortunately,
the starting point for flash graphene could
hardly be cheaper or more abundant: Vir-
tually any organic matter, including coffee
grounds, food scraps, old tires, and plastic
bottles, can be vaporized to make the mate-
rial. “We’re turning garbage into graphene,”
Duy says. jA
prominent neuroscientist whose lab
in Germany was targeted by animal
rights activists is heading to China,
where he says he will be freer to pur-
sue research on macaques and other
monkeys. Nikos Logothetis, one of
the directors at the Max Planck Institute
for Biological Cybernetics in Tübingen, also
says leaders of the Max Planck Society did
not defend him strongly enough when he
faced the activists and subsequent legal
problems in Germany.
“I would still consider staying here [in
Tübingen], continuing with rodents,” he
says, while doing primate work elsewhere.
But Germany’s widespread skepticism of
animal research and his disappointment
with Max Planck “made this impossible.”
Logothetis, who studies the brain’s vi-
sual system, told colleagues last week that
several group leaders from his department
will move in the coming months to a new
International Center for Primate Brain Re-
search (ICPBR) in Shanghai. Logothetis will
co-direct the center with neuroscientist
Poo Mu-Ming, scientific director of the Chi-
nese Academy of Sciences’s Center for Ex-
cellence in Brain Science and Intelligence
Technology; he will follow after remaining
lab members finish their projects. ICPBR
will house as many as 6000 nonhuman pri-Monkey facility
in China lures
neuroscientist
Animal rights conflict spurs
move of major German lab
ANIMAL RESEARCHMATERIALS SCIENCE
Nikos
LogothetisElectricity turns garbage
into high-quality graphene
Method could supply graphene in bulk, opening new uses
By Robert F. Service
An electric jolt provides abundant graphene in a flash.
NEWS | IN DEPTH
By Gretchen VogelPublished by AAAS