High purity nanoscale metal oxide powders and methods to produce such powders

• US 7,547,431 B2
• Filed: 12/10/2002
• Issued: 06/16/2009
• Est. Priority Date: 09/03/1996
• Status: Expired due to Fees

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Pfaffenbach, Karl, Yadav, Tapesh
• Primary Examiner(s): BOS, STEVEN J
• Application Number:
  US10/315,272
• Publication Number:
  US 20030124043A1
• Time in Patent Office: 2,380 Days
• Field of Search: 423/592.1, 423/593.1, 423/636, 423637-639, 423/263, 423/325, 423/604, 423/625, 423608-612, 423/632
• US Class Current: 423/592.1
• CPC Class Codes: B01J 19/088 giving rise to electric discharges for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00
• CPC Class Codes: B01J 2219/0886 Gas-solid
• CPC Class Codes: B01J 2219/0894 Processes carried out in the presence of a plasma
• CPC Class Codes: B22F 2202/13 Use of plasma
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 9/12 starting from gaseous material
• CPC Class Codes: B22F 9/14 using electric discharge
• CPC Class Codes: B22F 9/30 with decomposition of metal compounds, e.g. by pyrolysis
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/14 Methods for preparing oxides or hydroxides in general particular individual oxides or hydroxides, see the relevant groups of subclasses C01B - C01G or C25B, according to the element combined with the oxygen or hydroxy group
• CPC Class Codes: C01B 13/20 by oxidation of elements in the gaseous state; by oxidation or hydrolysis of compounds in the gaseous state
• CPC Class Codes: C01B 21/06 Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boronazides C01B21/08
• CPC Class Codes: C01B 21/0828 Carbonitrides or oxycarbonitrides of metals, boron or silicon
• CPC Class Codes: C01B 32/956 Silicon carbide
• CPC Class Codes: C01B 32/977 Preparation from organic compounds containing silicon
• CPC Class Codes: C01F 17/218 Yttrium oxides or hydroxides
• CPC Class Codes: C01F 17/235 Cerium oxides or hydroxides
• CPC Class Codes: C01F 5/06 by thermal decomposition of magnesium compounds calcining magnesite or dolomite C04B2/10
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 19/00 Compounds of tin
• CPC Class Codes: C01G 25/00 : Compounds of zirconium
• CPC Class Codes: C01G 49/04 : Ferrous oxide [FeO]
• CPC Class Codes: C01G 49/06 : Ferric oxide [Fe2O3]
• CPC Class Codes: C01G 49/08 : Ferroso-ferric oxide [Fe3O4]
• CPC Class Codes: C01G 53/04 : Oxides; Hydroxides
• CPC Class Codes: C01P 2002/34 : perovskite-type (ABO3)
• CPC Class Codes: C01P 2002/52 : containing elements as dopants
• CPC Class Codes: C01P 2004/54 : Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C01P 2004/61 : Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 : Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 : Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 : Surface area
• CPC Class Codes: C01P 2006/80 : Compositional purity
• CPC Class Codes: C04B 2235/3205 : Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
• CPC Class Codes: C04B 2235/3206 : Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 : Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3215 : Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3224 : Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3227 : Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 : Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3236 : Alkaline earth titanates
• CPC Class Codes: C04B 2235/3249 : containing also titanium oxide or titanates, e.g. lead zirconate titanate (PZT)
• CPC Class Codes: C04B 2235/3272 : Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
• CPC Class Codes: C04B 2235/3282 : Cuprates
• CPC Class Codes: C04B 2235/3286 : Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3293 : Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3427 : Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/3804 : Borides
• CPC Class Codes: C04B 2235/3817 : Carbides
• CPC Class Codes: C04B 2235/3826 : Silicon carbides
• CPC Class Codes: C04B 2235/3852 : Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/3895 : Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/449 : Organic acids, e.g. EDTA, citrate, acetate, oxalate
• CPC Class Codes: C04B 2235/5409 : expressed by specific surface values
• CPC Class Codes: C04B 2235/5445 : submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/5454 : nanometer sized, i.e. below 100 nm
• CPC Class Codes: C04B 2235/72 : Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/721 : Carbon content
• CPC Class Codes: C04B 35/62665 : Flame, plasma or melting treatment
• CPC Class Codes: C04B 41/89 : for obtaining at least two superposed coatings having different compositions

Abstract

A method of producing high purity nanoscale powders in which the purity of powders produced by the method exceeds 99.99%. Fine powders produced are of size preferably less than 1 micron, and more preferably less than 100 nanometers. Methods for producing such powders in high volume, low-cost, and reproducible quality are also outlined. The fine powders are envisioned to be useful in various applications such as biomedical, sensor, electronic, electrical, photonic, thermal, piezo, magnetic, catalytic and electrochemical products.

Claims

1. A method for producing high purity metal oxide powder comprising:

providing a feed comprising a precursor with a purity greater than 99.9% on metal basis;

suspending the feed in a gas in a mixing apparatus to create a gas-stream suspension, whereafter the gas-stream suspension is fed to a thermal reactor;

a first step wherein the feed suspended in a gas is processed at a temperature greater than 2000°

C. in the thermal reactor thereby producing a stream comprising vapor;

a second step wherein the stream comprising vapor is provided thermokinetic conditions such that it forms a stream comprising high purity metal oxide powder with a purity greater than 99.9% on metal basis; and

a third step wherein the stream comprising high purity metal oxide powder is quenched.

2. The method of claim 1, where the temperature is greater than 3000°

C.

3. The method of claim 1, wherein the high purity metal oxide powder comprises a submicron powder.

4. The method of claim 1, wherein the high purity metal oxide powder comprises a nanoscale powder.

5. The method of claim 1, wherein the high purity metal oxide powder comprises a multimetal, composition.

6. The method of claim 1, wherein the high purity metal oxide powder comprises cerium.

7. The method of claim 1, wherein the high purity metal oxide powder comprises a metal selected from the group consisting of:

aluminum, silicon, yttrium, barium, calcium, strontium, titanium, and zirconium.

8. The method of claim 1, wherein the high purity metal oxide powder comprises a metal selected from the group consisting of:

magnesium, iron and copper.

9. The method of claim 1, wherein the high purity metal oxide powder has a purity greater than 99.999% on metal basis.

10. The method of claim 1, wherein the gas comprises oxygen.

11. The method of claim 1, wherein the gas comprises an inert gas.

12. The method of claim 1, further comprising the act of filtering the high purity metal oxide powder from the stream.

13. The method of claim 1, wherein the first step comprises a plasma process.

14. The method of claim 13, wherein the plasma process comprises DC plasma.

15. The method of claim 1, wherein the step of providing thermokinetic conditions comprises cooling the stream comprising vapor.

16. The method of claim 1, wherein the precursor comprises fluid.

17. The method of claim 1, wherein the high purity metal oxide powder is stoichiometric.

18. The method of claim 1, wherein the high purity metal oxide powder is non-stoichiometric.

19. The method of claim 1, wherein the high purity metal oxide powder comprises a functionalized surface.

20. The method of claim 1, wherein the gas comprises at least one reactive fluid selected from the group consisting of:

water vapor, air and oxygen.

21. The method of claim 1, wherein the precursor comprises a composition of matter wherein at least one substance is selected from the group consisting of:

metal acetate, metal carboxylate, metal ethanoate, metal alkoxide, metal octoate, metal chelate, metal halide, metal azide, metal nitrate, metal sulfate, metal hydroxide, metal salt soluble in water, metal salt soluble in an organic solvent and an emulsion comprising a metal.

22. A method for producing high purity metal oxide powder comprising:

providing a plasma;

providing a feed comprising a precursor with a purity greater than 99.9% on metal basis;

suspending the feed in a gas comprising oxygen;

a step wherein the feed suspended in a gas comprising oxygen is processed in the plasma thereby producing a stream comprising vapor;

step wherein the stream comprising vapor is formed into a stream comprising high purity metal oxide nanopowder with a purity greater than 99.9% on metal basis; and

an additional step wherein the stream comprising high purity metal oxide powder is quenched.

23. The method of claim 22, wherein the plasma comprises a DC plasma.

24. The method of claim 22, wherein the high purity metal oxide powder comprises stoichiometric powder.

25. The method of claim 22, wherein the high purity metal oxide powder comprises non-stoichiometric powder.

26. The method of claim 22, wherein the feed suspended in a gas comprises a powder suspension.