Claims
- 1. A method for making macroporous ceramics, comprising:
combining a ceramic precursor with an aqueous or nonaqueous emulsion in which the polar phase thereof is an oil-immersible polar liquid; adding a base sufficient to induce gelation; drying the resultant gel; and calcining the dried gel.
- 2. The method of claim 1 wherein the emulsion is nonaqueous.
- 3. The method of claim 2 wherein the nonaqueous emulsion is an oil in formamide emulsion.
- 4. The method of claim 1 in which said emulsion has been stabilized by the incorporation of a surfactant.
- 5. The method of claim 4 in which a small amount of heavy oil soluble material that is oil soluble but which has very low solubility in the polar liquid is added to the oil phase of the emulsion.
- 6. The method of claim 5 in which said added material is silicone oil.
- 7. The method of claim 4 in which said surfactant is a triblock polymer of the formula (ethylene osxide)n-(proxylene oxide)m-(ethylene oxide)n wherein 2 n/m is a value from 0.3 to 0.4.
- 8. The method of claim 1 in which said oil is an alkane of from 8 to 20 carbon atoms.
- 9. The method of claim 8 wherein said alkane is isooctane.
- 10. The method of claim 8 wherein said alkane is decane.
- 11. The method of claim 8 wherein said alkane is hexane.
- 12. The method of claim 2 wherein said ceramic percursor is a metal oxide.
- 13. The method of claim 12 in which said metal oxide is selected from titanium dioxide, zirconium dioxide and silicon dioxide.
- 14. The method of claim 1 in which said emulsion is fractionated to obtain a desired size and distribution of emulsion droplets.
- 15. A method for making macroporous ceramics, comprising:
combining a metal oxide with an emulsion of an alkane in formamide; which also contains a surfactant and, in its oil phase, a small amount of oil-soluble material that is oil soluble but which has very low solubility in formamide; adding a base sufficient to induce gelatin; drying the resultant gel; and calcining the dried gel.
- 16. A macroporous ceramic having micropores of substantially uniform diameter uniformly dispersed therein.
- 17. The macroporous ceramic of claim 16 in which said pores are in the range of 0.5 μm to 5 μm micrometers.
- 18. The macroporous ceramic of claim 16 in which the ceramic is a metal oxide.
- 19. The macroporous ceramic of claim 18 in which said metal oxide is selected from titanium dioxide, zirconium dioxide and silicon dioxide.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims an invention disclosed in Provisional Application Ser. No. 60/056,805, filed Aug. 25, 1997, and claims the benefit of said provisional application pursuant to 37 CFR §1.78(a)(3).
Provisional Applications (1)
|
Number |
Date |
Country |
|
60056805 |
Aug 1997 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09139783 |
Aug 1998 |
US |
Child |
09747226 |
Feb 2001 |
US |