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

Patent · Fri Jan 01 04:00:00 UTC 1988

OSTI ID:866548

Smith, Richard D ^[1]

---

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
• 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

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