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A D V A N C E D M A T E R I A L S & P R O C E S S E S | J U L Y / A U G U S T 2 0 1 5
8 METALS | POLYMERS | CERAMICS
POLYMER RESEARCH LEADS
TO NEW CLASS OF MATERIALS
Macromolecular science will have
to add a new giant molecule to its lexi-
con thanks to cutting-edge polymer re-
search at The University of Akron, Ohio.
The research team led by Professor Ste-
phen Z.D. Cheng invented a new think-
ing pathway in the design and synthesis
of macromolecules by creating an origi-
nal class of giant tetrahedra.
The unique challenge of build-
ing macromolecules is to keep their
material-specific properties. This re-
quires the ability to create material de-
signed and engineered at the nanome-
ter scale for a specific task. Cheng and
his team asked themselves, “What kind
of structures do we need to transfer and
amplify microscopic functionalities to
macroscopic properties?”
Building on earlier work on gi-
ant surfactants, Cheng and his team
developed a new class of giant poly-
hedra. These precisely functionalized
nanoparticles were achieved by extend-
ing the molecular geometry from tra-
ditional 1D categories of giant surfac-
tants to 3D of tetrahedron shapes that
are the simplest to use. “It had never
been done before in soft matter, where
its engineering could be particularly
useful,” explains Cheng, “and it took
three years to design and synthesize.”
For more information: Stephen Z.D.
Cheng, 330.972.6931,
, .
LIGHTWEIGHT MEMBRANE
MUTES IN-FLIGHT AIRCRAFT
NOISE
Researchers from North Carolina
State University, Raleigh, and Massa-
chusetts Institute of Technology, Cam-
bridge, developed a membrane that
can be incorporated into aircraft to
drastically reduce the low-frequency
noise that penetrates the cabin.
Aircraft designs incorporate light-
weight materials with a honeycomb-like
structure into their wings and cabins.
The sandwiched honeycomb structure
makes it strong, and the light weight
makes the aircraft more fuel efficient.
But these honeycomb structures are
very bad at blocking low-frequency
noise—like that of an aircraft engine.
The solution is a thin, lightweight
membrane that covers one side of the
honeycomb structure like the skin of a
drum. When sound waves hit the mem-
brane, they bounce off rather than pass-
ing through. “It’s particularly effective
against low-frequency noise,” says Yun
Jing, an assistant professor at NC State.
“At low frequencies—sounds below 500
Hertz—the honeycomb panel with the
membraneblocks 100 to1000 timesmore
sound energy than the panel without
a membrane.” The membrane is made
of rubber that is roughly 0.25 mm thick,
adding approximately 6% to the over-
all weight of the honeycomb panel. For
more information: Yun Jing, 919.513.4673,
, .
Membranes can significantly reduce aircraft noise when inserted into the
honeycomb structures used in aircraft design. Courtesy of Yun Jing, NC State.
BRIEF
Scientists at the DOE’s Ames Laboratory, Iowa, created a new magnetic
alloy that is an alternative to traditional rare-earth permanent magnets.
The new alloy—a potential replacement for high-performance permanent
magnets found in automobile engines and wind turbines—eliminates
the use of one of the scarcest and most expensive rare earth elements,
dysprosium, and instead uses cerium, the most abundant rare earth.
.
Cerium is used to create a high-performance
magnet that is similar in performance to tradi-
tional dysprosium-containing magnets and
couldmake wind turbines less expensive to
manufacture. Courtesy of Ames Laboratory.