Aerosol reactor production of uniform submicron powders

Patent · Tue Feb 19 04:00:00 EST 1991

OSTI ID:867710

Flagan, Richard C ^[1]; Wu, Jin J ^[1]

---

1. Pasadena, CA

A method of producing submicron nonagglomerated particles in a single stage reactor includes introducing a reactant or mixture of reactants at one end while varying the temperature along the reactor to initiate reactions at a low rate. As homogeneously small numbers of seed particles generated in the initial section of the reactor progress through the reactor, the reaction is gradually accelerated through programmed increases in temperature along the length of the reactor to promote particle growth by chemical vapor deposition while minimizing agglomerate formation by maintaining a sufficiently low number concentration of particles in the reactor such that coagulation is inhibited within the residence time of particles in the reactor. The maximum temperature and minimum residence time is defined by a combination of temperature and residence time that is necessary to bring the reaction to completion. In one embodiment, electronic grade silane and high purity nitrogen are introduced into the reactor and temperatures of approximately 770.degree. K. to 1550.degree. K. are employed. In another embodiment silane and ammonia are employed at temperatures from 750.degree. K. to 1800.degree. K.

• Research Organization: California Institute of Technology (Los Angeles, CA)
• Assignee: California Institute of Technology (Los Angeles, CA)
• Patent Number(s): US 4994107
• Application Number: 07/248,486
• OSTI ID: 867710
• Country of Publication: United States
• Language: English

Related Subjects

/75/423/427/
1550
1800
750
770
accelerated
aerosol
agglomerate
ammonia
approximately
bring
chemical
chemical vapor
coagulation
combination
completion
concentration
defined
degree
deposition
electronic
embodiment
employed
formation
generated
grade
gradually
growth
homogeneously
increases
inhibited
initial
initiate
introduced
introducing
length
maintaining
maximum
maximum temperature
method
minimizing
minimum
mixture
nitrogen
nonagglomerated
particle
particles
particles generated
powders
producing
production
programmed
progress
promote
purity
rate
reactant
reactants
reaction
reactions
reactor
reactor product
residence
residence time
section
seed
silane
single
single stage
stage
stage reactor
submicron
submicron powder
sufficiently
temperature
temperatures
time
uniform
vapor
vapor deposition
varying