Glass powders, methods for producing glass powders and devices fabricated from same
Methods for producing glass powders are provided. The methods include generating an aerosol stream comprising droplets that include a liquid and a glass precursor. Glass particles are formed in the aerosol stream having a small average particle size. The powders can also have a small particle size, narrow size distribution, a high density and a spherical morphology. The invention also includes devices and products formed from the glass powders.
1. An aerosol method for making glass particles, the method comprising:
generating an aerosol stream, as generated the aerosol stream comprising droplets comprising a liquid and at least one precursor for glass material; and
in the aerosol stream, forming glass particles comprising the glass material, the glass particles having a weight average particle size of not greater than 5 microns and a particle density of at least 80% of the theoretical density of the glass material.
2. The method of claim 1 , wherein the at least one precursor comprises a salt.
3. The method of claim 1 , wherein the at least one precursor comprises a metal salt.
4. The method of claim 1 , wherein the at least one precursor comprises a metal oxide.
5. The method of claim 1 , wherein the at least one precursor comprises a metal nitrate.
6. The method of claim 1 , wherein the at least one precursor comprises a metal acetate.
7. The method of claim 1 , wherein the at least one precursor comprises at least one member selected from the group consisting of metal chlorides, metal sulfates, metal hydroxides and metal oxalates.
8. The method of claim 1 , wherein the forming comprises heating the aerosol stream in a thermal reactor.
9. The method of claim 8 , wherein the thermal reactor is a flame reactor.
10. The method of claim 8 , wherein during the heating, the aerosol stream reaches a maximum average stream temperature of greater than 800° C.
11. The method of claim 1 , wherein the droplets have a weight average size in a range of from 1 micron to 20 microns.
12. The method of claim 1 , wherein the droplets have a weight average size in a range of from 1 micron to 10 microns.
13. The method of claim 1 , wherein the droplets have a weight average size in a range of from 1 micron to 7 microns.
14. The method of claim 1 , wherein the droplets have a weight average size in a range of from 1 micron to 5 microns.
15. The method of claim 1 , wherein as generated the aerosol stream comprises greater than 1×10 6 of the droplets per cubic centimeter.
16. The method of claim 1 , wherein as generated the aerosol stream comprises greater than 5×10 6 of the droplets per cubic centimeter.
17. The method of claim 1 , wherein as generated the aerosol stream comprises greater than 1×10 7 of the droplets per cubic centimeter.
18. The method of claim 1 , wherein the glass particles comprise a dielectric glass composition.
19. The method of claim 1 , wherein the glass material is an oxide glass.
20. The method of claim 19 , wherein the oxide glass comprises at least:
a first component selected from the group consisting of SiO 2 , B 2 O 3 , P 2 O 5 and GeO 2 ; and
a second component selected from the group consisting of Al 2 O 3 , Bi 2 O 3 and PbO.
21. The method of claim 20 , wherein the oxide glass comprises an alkali oxide.
22. The method of claim 20 , wherein the oxide glass comprises at least one alkali oxide selected from the group consisting of an oxide of Li, an oxide of Na, an oxide of K, an oxide of Rb and an oxide of Cs.
23. The method of claim 20 , wherein the oxide glass comprises an alkaline earth oxide.
24. The method of claim 20 , wherein the oxide glass comprises at least one alkaline earth oxide selected from the group consisting of an oxide of Mg, an oxide of Ca, an oxide of Sr and an oxide of Ba.
25. The method of claim 20 , wherein the oxide glass comprises an alkali oxide and an alkaline earth oxide.
26. The method of claim 1 , wherein the weight average particle size is from 0.3 micron to 5 microns.
27. The method of claim 1 , wherein the weight average particle size is not greater than 3 microns.
28. The method of claim 27 , wherein the weight average particle size is at least 0.05 micron.
29. The method of claim 27 , wherein the weight average particle size is at least 0.1 micron.
30. The method of claim 1 , wherein the glass particles comprise at least 90 weight percent glass.
31. The method of claim 1 , wherein the glass particles comprise at least 95 weight percent glass.
32. The method of claim 1 , wherein:
the glass particles are substantially spherical, have a density of at least 90 percent of the theoretical density, have a weight average particle size of from 0.05 micron to 3 microns; and
the glass material comprises:
(i) at least one component selected from the group consisting of SiO 2 , B 2 O 3 , P 2 O 5 and GeO 2 ; and
(ii) at least one component selected from the group consisting of Al 2 O 3 , Bi 2 O 3 and PbO;
(iii) at least on component selected from the group consisting of alkali oxides and alkaline earth oxides.
33. The method of claim 32 , wherein the glass particles comprise no greater than 0.1 atomic percent impurities.
34. The method of claim 1 , wherein the generating comprises forming the droplets from a reservoir of the liquid feed ultrasonically energized by a plurality of ultrasonic transducers underlying the reservoir.
35. The method of claim 1 , wherein said glass particles have a particle density of at least about 90% of the theoretical density of the glass material.
36. The method of claim 1 , wherein said glass particles have a particle density of at least about 95% of the theoretical density of the glass material.