Process for forming transparent aerogel insulating arrays

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:865977

Tewari, Param H ^[1]; Hunt, Arlon J ^[2]

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1. Milpitas, CA
2. Oakland, CA

An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO.sub.2, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO.sub.2, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40.degree. C. instead of at about 270.degree. C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementry particles or cosmic rays.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• DOE Contract Number: AC03-76SF00098
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4610863
• OSTI ID: 865977
• Country of Publication: United States
• Language: English

Related Subjects

process
forming
transparent
aerogel
insulating
arrays
improved
supercritical
drying
silica
described
type
utilizing
steps
hydrolyzing
condensing
aloxides
form
alcogels
subsequent
step
removes
alcohol
aerogels
improvement
additional
formed
substituting
solvent
critical
temperature
resulting
gels
dried
selected
provide
array
substantially
reduced
days-to-hours
time
period
occurs
40
degree
270
provides
increased
yields
scale
structurally
sound
sheets
slabs
accordance
replace
air
gap
double
glazed
window
example
substantial
reduction
heat
transfer
utilized
windows
refrigerators
ovens
walls
doors
active
material
detectors
analyzing
energy
elementry
particles
cosmic
rays
provides increased
process provides
substantially reduced
air gap
improved process
critical temperature
active material
heat transfer
time period
substantially reduce
substantial reduction
resulting gels
structurally sound
transparent aerogel
increased yields
supercritical drying
drying process
supercritical temperature
silica aerogel
subsequent step
cosmic rays
type utilizing
increased yield
transparent silica
forming transparent
additional step
aerogel insulating
double glazed
/423/502/