Polyimide Aerogel. Credit: NASA
major improvement in the world’s lightest solid material and best solid
insulating material, described here today, may put more of this
space-age wonder into insulated clothing, refrigerators with thinner
walls that hold more food, building insulation and other products.
report, on development of a new flexible “aerogel”?stuff so light it
has been called “solid smoke”?was part of the 244th National Meeting
& Exposition of the American Chemical Society, the world’s largest
scientific society. More than 14,000 scientists and others are in the
City of Brotherly Love for the event, which features 8,600 reports on
new development in science and other topics.
Mary Ann B. Meador, Ph.D., explained that traditional aerogels, developed decades ago and made from silica, found in beach sand,
are brittle, and break and crumble easily. Scientists have improved the
strength of aerogels over the years, and Meador described one of these
muscled-up materials developed with colleagues at the NASA Glenn
Research Center in Cleveland, Ohio.
new aerogels are up to 500 times stronger than their silica
counterparts,” Meador said. “A thick piece actually can support the
weight of a car. And they can be produced in a thin form, a film so
flexible that a wide variety of commercial and industrial uses are
aerogels, for instance, could be used in a new genre of
super-insulating clothing that keeps people warm in the cold with less
bulk than traditional “thermal” garments. Tents and sleeping bags would
have the same advantages. Home refrigerator and freezer walls insulated
with other forms of the material would shrink in thickness, increasing
storage capacity. Meador said that the aerogel is 5-10 times more
efficient than existing insulation, with a quarter-inch-thick sheet
providing as much insulation as 3 inches of fiberglass. And there could
be multiple applications in thin-but-high-efficiency insulation for
buildings, pipes, water heater tanks and other devices.
envisions one use in an advanced re-entry system for spacecraft
returning to Earth from the International Space Station, and perhaps
other missions. Re-entry vehicles need a heat shield that keeps them
from burning up due to frictional heating from Earth’s atmosphere. Those
shields can be bulky and heavy. So NASA is exploring use of a heat
shield made from flexible aerogel that inflates like a balloon when
spacecraft enter the atmosphere.
said the material also could be used to insulate spacesuits. However,
it likely would not be good for firefighting clothing products, which
require protection beyond the 575 F limits of the aerogel.
produced the stronger new aerogels in two ways. One involved making
changes in the innermost architecture of traditional silica aerogels.
They used a polymer, a plastic-like material, to reinforce the networks
of silica that extend throughout an aerogel’s structure. Another
involved making aerogels from polyimide, an incredibly strong and
heat-resistant polymer, or plastic-like material, and then inserting
brace-like cross-links to add further strength to the structure.
Source: American Chemical Society