Method of making supercritical fluid molecular spray films, powder and fibers

Patent · Fri Jan 01 00:00:00 EST 1988

OSTI ID:866548

Smith, Richard D ^[1]

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1. Richland, WA

Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a heated nozzle having a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. In another embodiment, the temperature of the solution and nozzle is elevated above the melting point of the solute, which is preferably a polymer, and the solution is maintained at a pressure such that, during expansion, the solute precipitates out of solution within the nozzle in a liquid state. Alternatively, a secondary solvent mutually soluble with the solute and primary solvent and having a higher critical temperature than that of primary solvent is used in a low concentration (<20%) to maintain the solute in a transient liquid state. The solute is discharged in the form of long, thin fibers. The fibers are collected at sufficient distance from the orifice to allow them to solidify in the low pressure/temperature region.

• Research Organization: Battelle Memorial Institute, Columbus, OH (United States)
• DOE Contract Number: AC06-76RL01830
• Assignee: Battelle Memorial Institute (Richland, WA)
• Patent Number(s): US 4734227
• OSTI ID: 866548
• Country of Publication: United States
• Language: English

Related Subjects

method
supercritical
fluid
molecular
spray
films
powder
fibers
solid
deposited
fine
powders
formed
dissolving
material
solution
elevated
pressure
rapidly
expanding
heated
nozzle
orifice
region
relatively
produces
directed
substrate
deposit
film
thereon
discharged
collection
chamber
collect
embodiment
temperature
melting
solute
preferably
polymer
maintained
expansion
precipitates
liquid
alternatively
secondary
solvent
mutually
soluble
primary
critical
concentration
20
maintain
transient
form
collected
sufficient
distance
allow
solidify
molecular spray
rapidly expanding
critical temperature
supercritical fluid
solid material
collection chamber
elevated pressure
fine powder
transient liquid
solid films
powders formed
fluid solution
fine powders
sufficient distance
film thereon
solid film
fluid molecular
spray film
/264/528/