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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 A N U A R Y 2 0 1 5
1 2
A TEAM AT PLYMOUTH
UNIVERSITY, UK, FOUND
THAT IN-MOLD GEL-COATING
COULD REDUCE STYRENE
LEVELS BY MORE THAN 98%
PROVIDING A ROUTE TO
REDUCED ENVIRONMENTAL
IMPACT. .
SURFACE ENGINEERING
FABRICATION PROCESS
PRODUCESHIGHLY ALIGNED
POLYMER FILMS
Researchers from Massachusetts
Institute of Technology (MIT), Cambridge,
demonstrated a novel automated
fabrication process consisting of a three-
step sol-gel extrusion, structure freezing
and drying, and mechanical drawing
process, which results in production of
highly aligned polymer films (HAPFs).
Although HAPFs are in demand, previous
fabrication methods were limited to
manual, lab-scale batch processes.
By manipulating the polymers’ molecular
chains first by disentanglement followed
by macroscopic plastic deformation-
induced alignment, material properties
can be improved. This high-throughput
platform uses Couette flow for enhanced
chain disentanglement; a constant-
force adaptive-thickness mechanical
drawing system that aids in uniform film
production; and an automated scalable
platform—successfully demonstrating a
desktop printer-sized fabrication platform
for HAPFs in a commercially viable form
factor. .
VARIABLE GLASSCOATINGS
TOSTOP CONDENSATION
ONWINDOWS
Triple glazing is intended to keep as
much of the expensive heating energy
inside houses as possible, but a drop
in outside temperature causes the
outermost pane to cool down significantly
overnight, and moisture in the air is
deposited as condensation, resulting in
misty windows.
The Megatron sputtering system,
developed by researchers at the
Fraunhofer Institute for Surface
Engineering and Thin Films IST, Germany,
opens the way to the development of
entirely new coating systems for a variety
of applications. In the case of triple
glazing on windows, researchers
deliberately contaminate the coating
material with niobium in order to make
it conductive. “Unlike conventional
sputtering systems, Megatron allows
us to vary the doping concentration to
any required level. It also enables us to
increase the coating rate and obtain a
smoother surface,” says IST group leader
Volker Sittinger.
The system allows entirely new coatings
to be created by combining materials in
a film that cannot be mixed in the form of
a target, and were previously impossible
to produce. For example, a combination
of tungsten and titanium dioxide could
be used to create self-cleaning surfaces
for interior spaces. When UV light hits a
film of pure titanium dioxide, it breaks
down any organic particles found there.
If the titanium dioxide film is doped
with tungsten, the organic dirt particles
are broken down and detached when
exposed to natural daylight.
BRIEFS
Kloeckner Metals, Roswell, Ga., will exclusively distribute physical vapor
deposition (PVD)-coated stainless and aluminum sheet products made by Double
Stone Steel, whose process of PVD titanium ion coating improves stainless steel
performance by enhancing corrosion, scratch, and wear resistance. Compared to
electroplating or painting, the PVD process does not discharge gas, water waste,
or other residues. ,
SEM images demonstrate drastic changes in polyethylene surface morphology resulting
from fabrication. The initial polymer particulate material resembles tightly wound balls
of string (a). Compared to the extruded sample (b), polymer disentanglement as a result
of the high shear rate Couette-based extrusion process is evident. SEM images of 50× (c),
and 100× (d) drawn films. Film structure is uniform fibrous with minimal defects. Scale bar
represents 100 µm (a), and 2 µm (b-d). Courtesy of Technology.
The Megatron lets scientists create
new combinations of materials.
Courtesy of Fraunhofer IST.