Silica powders for powder evacuated thermal insulating panel and method

Patent · Sat Jan 01 00:00:00 EST 1994

OSTI ID:869675

Harris, Michael T ^[1]; Basaran, Osman A ^[2]; Kollie, Thomas G ^[2]; Weaver, Fred J ^[1]

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1. Knoxville, TN
2. Oak Ridge, TN

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2 /g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Assignee: Martin Marietta Energy Systems, Inc. (Oak Ridge, TN)
• Patent Number(s): US 5376449
• OSTI ID: 869675
• Country of Publication: United States
• Language: English

Related Subjects

silica
powders
powder
evacuated
thermal
insulating
panel
method
spherical
porous
particles
median
size
100
nanometers
diameter
pour
packing
density
cm
external
surface
range
90
600
described
prepared
reacting
tetraakyl
silicate
ammonia
water
alcohol
solvent
distilling
solution
reaction
remove
recover
resulting
aqueous
slurry
dried
ball-milled
provide
defined
internal
porosity
nanometer
panels
significantly
r-values
obtainable
previously
silica powder
packing density
porous silica
alcohol solvent
insulating panel
external porosity
external surface
silica particles
aqueous slurry
thermal insulating
powder evacuated
evacuated thermal
silica powders
provide powder
nanometer size
tetraakyl silicate
pour packing
median size
resulting aqueous
particles provide
defined internal
insulating panels
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