Aerogel History Part II
Following Dr. Kistler’s discovery of the process of making aero
gels in the mid 1930’s using a supercritical alcohol drying process,
which involved a tedious process with many possible errors. Numerous
more advances were made using this solid with ninety-five percent air.
The Mosanto Corporation, under the trade name Santocel, commercialized
the first aero gel in 1942. The process involved soaking a sodium silicate
solution in sulfuric acid, then repeatedly washing it in alcohol before
drying it at high pressures. Mosanto described the product as "a
light, friable, slightly opalescent solid containing as much as 95
percent air volume. It is a very effective heat insulating material." Masonta
received little acceptance for this material and eventually drops the
project due to the cost in testing, safety hazards such as alcohol
under high temperatures and pressures, and failed efforts to bring
this product into a larger scale.
1970 era, interest in the technology for aero gel becomes scarce,
until the French Government approached American scientists looking
for a way to store their space rocket’s fuel and oxygen. When
this global interest for the product emerged, NASA began testing the
materials for similar uses. Although, NASA was using Dr. Kristler’s
method. This method of drying using alcohol was mainly used to ensure
the consistency of the volume. This process was again proving to go
Throughout the eighties, companies such as: BASF, Thermolux, Aerojet,
Airglass try a larger scaled process which involved cooling gel in
low-temperatures while using carbon dioxide. These companies also failed
to keep the project.
In 1992, researchers at the University of New Mexico discovered a process
of creating aero gels at low temperatures. They first coat the gel
then allow it to dry. As the drying process begins the gel begins to
shrink, although the coating does not allow for the gel to shrink because
of the density and phase change rate. The aero gel then becomes a solid
structure with no impurities. This new process allows for continuation
of manufacturing aero gels mainly for insulation, and reduces the manufacturing
costs while decreasing safety concerns while testing.
Following the success of the newfound process, Armstrong, Hoechst,
Dow Corning, NanoPore and Cabot all start programs to develop a commercial,
large-scale process for manufacturing aero gels. While these companies
are testing for versatility of the product, marketing studies are conducted
to confirm the value of the aero gel to industries.
Beginning in 1996 and continuing into 1998, Dow Corning, Hoechst and
Cabot develop independent variations of the “silation technology” used
to make aero gels. All three companies file a series of patents for
their new processes, and for potential applications for aero gels.
With the success of the three companies comes strategy. Cabot purchases
the Hoechst project in 1999, then licenses the Dow project to then
gain all the industrial advances under one roof. Along with these
licenses, Cabot also buys a pilot plant, the patent estate, and
aspects for the aero gel.
In 2001, Cabot develops a unified process from the three they now
posses. While possessing all three processes, Cabolt begins adding
to strengthen, lighten, and broaden the acoustic properties.
In October of 2002, the first continuous commercial process for
the manufacture of aero gels begins with the completion of the
plant. Mass quantities of aero gel begin to enter the market.
In December of that year, showcase projects are completed and displayed.
leading industries in various markets are influencing the development
of aero gel technologies.
Michael and Arlon Hunt. A Brief History of Silica Aerogels. Berkeley:
Ernest Orlando Lawrence Berkeley Laboratory, (no date, but after
- The Columbia Electronic Encyclopedia,
6th ed. Copyright © 2003,
Columbia University Press.