METHOD FOR THE PRODUCTION OF MULTIPHASE COMPOSITE MATERIALS USING MICROWAVE PLASMA PROCESS

• US 20140217630A1
• Filed: 03/13/2014
• Published: 08/07/2014
• Est. Priority Date: 12/04/2012
• Status: Active Grant

• Current Assignee: 6K Incorporated
• Original Assignee: Amastan LLC
• Inventors: Redjdal, Makhlouf, Hadidi, Kamal
• Granted Patent: US 9,242,224 B2
• Time in Patent Office: Days
• US Class Current: 264/10
• CPC Class Codes: B01J 19/126 Microwaves
• CPC Class Codes: C01B 13/34 by oxidation or hydrolysis of sprayed or atomised solutions
• CPC Class Codes: C01F 17/34 Aluminates, e.g. YAlO3 or Y3-xGdxAl5O12
• CPC Class Codes: C01F 7/162 Magnesium aluminates
• CPC Class Codes: C01P 2002/02 Amorphous compounds
• 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 2004/32 Spheres
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/528 Spheres
• CPC Class Codes: C04B 2235/764 Garnet structure A3B2(CO4)3
• CPC Class Codes: C04B 35/44 based on aluminates
• CPC Class Codes: C04B 35/443 Magnesium aluminate spinel
• CPC Class Codes: C04B 35/6263 characterised by their solids loadings, i.e. the percentage of solids
• CPC Class Codes: C04B 35/62665 Flame, plasma or melting treatment
• CPC Class Codes: C04B 35/645 Pressure sintering
• CPC Class Codes: C04B 35/6455 Hot isostatic pressing

Abstract

Disclosed herein is a method to produce multiphase composite materials directly from solution precursor droplets by a fast pyrolysis process using a microwave plasma embodiment containing a microwave generating source, a dielectric plasma torch, and a droplet maker. Here, using homogenous solution precursors, droplets are generated with a narrow size distribution, and are injected and introduced into the microwave plasma torch with generally uniform thermal path. The generally uniform thermal path in the torch is achieved by axial injection of droplets into an axisymmetric hot zone with laminar flows. Upon exposing to high temperature within the plasma with controlled residence time, the droplets are pyrolyzed and converted into particles by quenching with a controlled rate of the exhaust gas in a gas chamber. The particles generated have generally uniform sizes and uniform thermal history, and can be used for a variety of applications.

Claims

1. A method of making particles using a microwave generated plasma comprising:

a. preparing a salt solution in water, in organic solvent, or in a mixture of water and organic solvent;

b. generating precursor droplets from said salt solution using a feed injection device;

c. introducing axially said precursor droplets into a microwave plasma torch;

d. entraining said precursor droplets using gas flows towards a microwave generated plasma;

e. exposing said precursor droplets to high temperature within said microwave generated plasma;

f. controlling the residence time of said precursor droplets in said microwave plasma;

g. controlling quenching rates of the exhaust gas in a gas chamber;

h. filtering the exhaust gas of said microwave generated plasma; and

i. extracting particles from said exhaust gas.

2. The method of claim 1, wherein said step of preparing a salt solution is prepared by further adding an acid in water, organic solvent, or in a mixture of water and organic solvent.

3. The method of claim 1, wherein said step of preparing a salt solution is prepared by combining at least a first solution and a second solution.

4. The method of claim 3, further comprising preparing said first solution by:

mixing water and organic solvent;

adding an acid in water;

or

adding an acid in a mixture of water and organic solvent.

5. The method of claim 3, further comprising preparing said second solution by:

dissolving at least one salt in water;

or

dissolving at least one salt in mixture of water and organic solvent.

6. The method of claim 3, further comprising preparing said first solution by:

mixing water and ethylene glycol;

adding citric acid in water;

or

adding citric acid in a mixture of water and ethylene glycol.

7. The method of claim 1, wherein said step of preparing a salt solution is prepared in a mixture of water and organic solvent and further selecting the organic solvent from a group consisting of ethanol, methanol, 1-propanol, 2-propanol, tetrahydrofuran, and a combination thereof.

8. The method of claim 1, wherein said step of preparing a salt solution is prepared by selecting a salt from a group consisting cations of alkali metals such as lithium, sodium, potassium, rubidium, and a combination thereof;

alkaline earth metals such as magnesium, calcium, strontium, barium, and a combination thereof;

transition metals such as scandium, yttrium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, and a combination thereof;

post transition metals such as aluminum, gallium, indium, tin, thallium, lead, bismuth, and a combination thereof;

lanthanides such as lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and a combinations thereof;

actinides such as thorium;

metalloids such as boron, silicon, germanium, arsenic, antimony, tellurium, and a combinations thereof; and

nonmetals such as carbon, phosphorus, sulfur, and selenium, and a combination thereof.

9. The method of claim 1,

wherein said step of preparing a salt solution is prepared by dissolving salts comprising cations of:

aluminum;

yttrium, scandium, and any combination thereof; and

dopants selected from a group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and a combination thereof.

10. The method of claim 1, wherein said step of preparing a salt solution is prepared by dissolving salts comprising cations of:

aluminum, zirconium, silicon, magnesium, and manganese, and any combination thereof, or the lanthanide cerium; and

doping transition metals selected from a group consisting of palladium, platinum, nickel, silver, gold, ruthenium, rhodium, vanadium, molybdenum, cobalt, tungsten, and any combination thereof, or nonmetal phosphorus.

11. The method of claim 1, wherein said step of preparing a salt solution is prepared by dissolving salts comprising cations of magnesium and yttrium.

12. The method of claim 1, wherein said step of preparing a salt solution is prepared by dissolving salts comprising cations of magnesium and aluminum.

13. The method of claim 1, wherein said step of preparing a salt solution is prepared by dissolving salts comprising cations of lanthanum;

magnesium; and

aluminum.

14. The method of claim 1, wherein said step of preparing a salt solution is prepared by dissolving salts comprising cations of:

zirconium; and

yttrium or samarium.

15. The method of claim 1, wherein said step of preparing a salt solution is prepared by selecting a salt from a group consisting anions of nitrate, acetate, citrate, sulfate, carbonate, chloride, phosphate, alkoxide, atrane, tetraethyl orthosilicate, metallic borohydride, and a combination thereof.

16. The method of claim 1, wherein said step of entraining said precursor droplets includes using at least two concentric laminar flows.

17. The method of claim 16, wherein said step of using at least two concentric laminar flows is prepared by selecting gases from a group consisting of air, oxygen, argon, methane, ammonia, nitrogen, and a combination thereof.

18. The method of claim 1, wherein said step of controlling quenching rates is further adjusted by selecting a rate no less than 10³ Kelvin per second (K/s) to no more than 10⁶ K/s.

19. The method of claim 18, wherein said step of controlling quenching rates by selecting a chamber with controllable atmosphere.