Page 62 - Plastics News October 2019

TECHNOLOGY

High-performance exterior PDRC polymer

esearchers at Columbia Engineering have invented a VRODU UHÁHFWDQFH 5 ! DQG KLJK WKHUPDO HPLWWDQFH
Rhigh-performance exterior PDRC polymer coating with (İ a NHSW LW VLJQLÀFDQWO\ FRROHU WKDQ LWV HQYLURQPHQW
nano-to-microscale air voids that acts as a spontaneous XQGHU ZLGHO\ GLIIHUHQW VNLHV H J E\ Ý& LQ WKH ZDUP
air cooler and can be fabricated, dyed, and applied like DULG GHVHUW LQ $UL]RQD DQG Ý& LQ WKH IRJJ\ WURSLFDO
paint on rooftops, buildings, water tanks, vehicles, even environment of Bangladesh.
spacecraft -- anything that can be painted. They used a
solution-based phase-inversion technique that gives the Method to change fundamental
polymer a porous foam-like structure. The air voids in the
SRURXV SRO\PHU VFDWWHU DQG UHÁHFW VXQOLJKW GXH WR WKH architecture of polymers
difference in the refractive index between the air voids
and the surrounding polymer. The polymer turns white
Florida State University research team has
and thus avoids solar heating, while its intrinsic emittance A developed methods to manipulate polymers in a
FDXVHV LW WR HIÀFLHQWO\ ORVH KHDW WR WKH VN\ 7KH VWXG\ LV way that changes their fundamental structure, paving
published online today in Science.
the way for potential applications in cargo delivery
and release, recyclable materials, shape-shifting soft
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polymer completely change its architecture through
a chemical response," said FSU Assistant Professor of
Chemistry Justin Kennemur. "In nature this happens
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The cellular machinery changes the design of natural
biopolymers
and hence their
properties.
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The team -- Yuan Yang, assistant professor of materials with synthetic
science and engineering; Nanfang Yu, associate professor polymers."
of applied physics; and Jyotirmoy Mandal, lead author The research
RI WKH VWXG\ DQG D GRFWRUDO VWXGHQW LQ <DQJ V JURXS DOO is published in
department of applied physics and applied mathematics) the Journal of
-- built upon earlier work that demonstrated that simple the American
plastics and polymers, including acrylic, silicone, and Chemical Society.Polymers are materials made of
PET, are excellent heat radiators and could be used for large molecular chains composed of chemically
PDRC. The challenges were how to get these normally similar repeating units. They touch almost every part
WUDQVSDUHQW SRO\PHUV WR UHÁHFW VXQOLJKW ZLWKRXW XVLQJ of everyday life and include materials like plastics,
VLOYHU PLUURUV DV UHÁHFWRUV DQG KRZ WR PDNH WKHP HDVLO\ rubbers and gels and natural biological structures such
deployable. They decided to use phase-inversion because as DNA and proteins.In the big picture, Kennemur is
it is a simple, solution-based method for making light- working to develop high-performance polymers with
scattering air-voids in polymers. Polymers and solvents super-elastic and super-soft properties that could
are already used in paints, and the Columbia Engineering be used as joint or cartilage replacements. To do
method essentially replaces the pigments in white paint that, he and his team are exploring the boundaries of
ZLWK DLU YRLGV WKDW UHÁHFW DOO ZDYHOHQJWKV RI VXQOLJKW IURP how existing polymers respond to stimuli and can be
89 WR LQIUDUHG 7KLV VLPSOH EXW IXQGDPHQWDO PRGLÀFDWLRQ reorganized for better performance. Polymers that
\LHOGV H[FHSWLRQDO UHÁHFWDQFH DQG HPLWWDQFH WKDW HTXDO spontaneously "unzip" or deteriorate in response to an
or surpass those of state-of-the-art PDRC designs," says external stimulus have gained traction from scientists
0DQGDO 7KH UHVHDUFKHUV IRXQG WKHLU SRO\PHU FRDWLQJ V KLJK for their potential use in a variety of applications.

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