Combustion of emulsions: A method and process for producing fine powders

• US 5,984,997 A
• Filed: 03/23/1998
• Issued: 11/16/1999
• Est. Priority Date: 08/29/1997
• Status: Expired due to Term

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: Nanomaterials Research Corp.
• Inventors: Bickmore, Clint, Galde, Benjamin, Yadav, Tapesh, Freim, John
• Primary Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US09/046,465
• Time in Patent Office: 603 Days
• Field of Search: 75/343, 75/351, 75/353, 75/362, 75/363
• US Class Current: 75/343
• CPC Class Codes: B01J 6/008 Pyrolysis reactions of hydrocarbons C10G9/00
• 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: C01G 15/00 Compounds of gallium, indium or thallium
• CPC Class Codes: C01G 19/00 Compounds of tin
• CPC Class Codes: C01G 19/006 Compounds containing, besides tin, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01G 3/006 Compounds containing, besides copper, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01G 41/02 Oxides; Hydroxides
• CPC Class Codes: C01G 53/006 Compounds containing, besides nickel, two or more other elements, with the exception of oxygen or hydrogen nickelates C01G53/40
• CPC Class Codes: C01P 2002/32 spinel-type (AB2O4)
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2002/54 one element only
• CPC Class Codes: C01P 2002/60 Compounds characterised by their crystallite size
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/16 Nanowires or nanorods, i.e. solid nanofibres with two nearly equal dimensions between 1-100 nanometer
• CPC Class Codes: C01P 2004/32 Spheres
• 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: Y10S 977/776 : Ceramic powder or flake
• CPC Class Codes: Y10S 977/777 : Metallic powder or flake

Abstract

A process for producing nanoscale powders, and the powders so produced. The process comprises mixing an emulsion comprising all of the elements of the desired powder composition and a combustible fuel, and then combusting that emulsion to produce a powder. Powders with a median particle size of less than 50 nm have been made by this process. The process is suitable for the production of many types of powders, including particles and nanowhiskers of simple, doped, and polymetallic powders.

Claims

1. A process for producing fine powders of a selected composition, comprising

forming a liquid emulsion comprising precursor elements of the selected composition and a combustible fuel;

combusting the emulsion to cause the precursor elements to combine to form a powder of the selected composition; and

collecting the powder formed.

2. The process of claim 1, wherein the precursor elements comprise

at least two metals selected from the group consisting of the s group, p group, d group, and f group of the periodic table, and

at least one non-metal selected from the group consisting of carbon, nitrogen, oxygen, boron, phosphorus, sulfur, chalcogens, and halogens.

3. The process of claim 1, wherein the combustible fuel is selected from the group consisting of ethanol, butanols, amyl alcohol, octanols, and other straight and branched alcohols;

kerosene, mineral spirits, gasoline, naphtha, liquified petroleum gas, and other petroleum derivatives; and

acetic acid, acetone, ethyl acetate, toluene, glycols, ethers, and liquid ammonia.

4. The process of claim 1, wherein the formed powder is a nanopowder.

5. The process of claim 1, wherein the formed powder has a median particle size of less than 1 μ

m.

6. The process of claim 1, wherein the formed powder has a median particle size of less than 100 nm.

7. The process of claim 1, wherein the formed powder has a median particle size of less than 50 nm.

8. The process of claim 1, wherein the emulsion is a polar-in-non-polar emulsion.

9. The process of claim 1, wherein the emulsion is a non-polar-in-polar emulsion.

10. The process of claim 1, wherein the emulsion is a non-polar-in-non-polar emulsion.

11. The process of claim 1, wherein the emulsion is a polar-in-polar emulsion.

12. The process of claim 1, wherein the emulsion includes dopants.

13. The process of claim 1, wherein the emulsion comprises a mixture of one or more component emulsions containing different precursor elements.