Ultrafine metal oxide powders by flame spray pyrolysis
First Claim
1. A process for the preparation of ultrafine metal oxide or mixed metal oxide ceramic particles having mean particle sizes in the range of 2-500 nm, said process comprising:
- a) aerosolizing a ceramic precursor solution comprising one or more glycolato polymetallooxanes in a volatile organic solvent or volatile flammable organic solvent mixture, said glycolato polymetallooxane(s) present in said volatile solvent(s) in an amount of from 1 weight percent to 30 weight percent of said ceramic precursor solution, said glycolato polymetallooxane(s) having bound therein in excess of 90% of the metal content of said metal oxide or mixed metal oxide, to form a ceramic precursor solution aerosol containing droplets of said ceramic precursor solution;
b) supplying oxygen to said ceramic precursor solution aerosol in an amount at least stoichiometrically equivalent to combustible material contained in said ceramic precursor solution aerosol to form an aerosol and oxygen mixture;
c) igniting said aerosol an oxygen mixture and forming metal oxide or mixed metal oxide ceramic particles thereby and a gaseous effluent containing products of combustion; and
d) separating said metal oxide or said mixed metal oxide ceramic particles from said gaseous effluent to recover an ultrafine ceramic particle product.
2 Assignments
0 Petitions
Accused Products
Abstract
Ultrafine metal oxide and mixed metal oxide ceramic particles are prepared by flame spray pyrolysis of a ceramic precursor solution containing one or more gycolato polymetallooxanes dissolved in a volatile organic solvent. Recycle of the nanosized particles disposed in additional ceramic precursor solution leads to larger particles. The metal oxide and mixed metal oxide particles may be converted to the respective nitrides by high temperature ammonolysis. The process produces high quality ceramic particles from inexpensive and relatively non-toxic reagents in high space-time yield.
-
Citations
18 Claims
-
1. A process for the preparation of ultrafine metal oxide or mixed metal oxide ceramic particles having mean particle sizes in the range of 2-500 nm, said process comprising:
-
a) aerosolizing a ceramic precursor solution comprising one or more glycolato polymetallooxanes in a volatile organic solvent or volatile flammable organic solvent mixture, said glycolato polymetallooxane(s) present in said volatile solvent(s) in an amount of from 1 weight percent to 30 weight percent of said ceramic precursor solution, said glycolato polymetallooxane(s) having bound therein in excess of 90% of the metal content of said metal oxide or mixed metal oxide, to form a ceramic precursor solution aerosol containing droplets of said ceramic precursor solution; b) supplying oxygen to said ceramic precursor solution aerosol in an amount at least stoichiometrically equivalent to combustible material contained in said ceramic precursor solution aerosol to form an aerosol and oxygen mixture; c) igniting said aerosol an oxygen mixture and forming metal oxide or mixed metal oxide ceramic particles thereby and a gaseous effluent containing products of combustion; and d) separating said metal oxide or said mixed metal oxide ceramic particles from said gaseous effluent to recover an ultrafine ceramic particle product. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
Specification