Claims
- 1. A method of stabilizing a glass-ceramic body against irreversible changes in dimension and/or in CTE from exposure to a humid atmosphere, the body having a large, internal surface area, the method comprising coating the body with an aqueous solution of an alkali metasilicate, or with a solution of a silane that is strongly non-polar with respect to water, or with successive applications of the alkali metasilicate and the silane.
- 2. A method in accordance with claim 1 which comprises coating the glass-ceramic body with a non-aqueous solution of a silane that is strongly non-polar with respect to water.
- 3. A method in accordance with claim 2 which comprises coating the glass-ceramic with a dilute solution of an alkali metasilicate prior to applying the dilute solution of a non-polar silane.
- 4. A method in accordance with claim 1 wherein the alkali metasilicate is sodium metasilicate and the silane is (pentafluorophenyl)propyltrimethoxy silane.
- 5. A method in accordance with claim 1 wherein the silane has hydrolyzable groups that react with water on the glass-ceramic surface to form a linkage with the surface.
- 6. A method in accordance with claim 1 which comprises soaking the glass-ceramic body in water for a period of time and drying prior to applying a coating.
- 7. A method in accordance with claim 1 which comprises applying a coating to the surface of the glass-ceramic and determining the effectiveness of the coating by repeatedly measuring the frequency of a selected mechanical resonance mode at spaced intervals of time.
- 8. A method in accordance with claim 1 which comprises providing a non-polar silane having alkoxy groups and a glass-ceramic body having water molecules on its surface, applying a coating of the silane to the glass-ceramic, reacting the alkoxy group on the silane with the water molecules to hydrolyze the alkoxy group, and link the hydrolyzed silane to the glass-ceramic surface.
- 9. A method in accordance with claim 1 wherein the non-polar silane is (pentafluorophenyl)propyltrimethoxy silane.
- 10. A glass-ceramic body that has microcracks extending into the body from its surface, and that has a non-polar silane linked to the walls of the microcracks and blocking access of moisture to the microcrack surfaces.
- 11. A glass-ceramic body in accordance with claim 10 wherein the microcracks form a continuous porous network extending into the body from its surface.
- 12. A glass-ceramic body in accordance with claim 10 wherein the silane is hydrolyzed and is linked to hydroxyl ions on the glass-ceramic surface.
- 13. A glass-ceramic body in accordance with claim 10 wherein the non-polar silane is the hydrolyzed product of (pentafluorophenyl)propyltrimethoxy silane.
- 14. A glass-ceramic body in accordance with claim 10 that has a sodium metasilicate coating overlaid with the non-polar silane coating.
- 15. A glass-ceramic body in accordance with claim 10 wherein the glass-ceramic is a member of the aluminosilicate family.
- 16. A glass-ceramic body in accordance with claim 15 wherein the glass-ceramic has a primary crystal phase of beta-eucryptite.
- 17. A telecommunications system component comprising an optical element having a positive coefficient of thermal expansion in conjunction with a substrate having a negative coefficient of thermal expansion, the substrate having a microcracked glass-ceramic of the aluminosilicate family having a non-polar silane coating blocking entry of moisture to the microcracks.
- 18. A component in accordance with claim 17 wherein the substrate is a glass-ceramic having a primary crystal phase of beta-eucryptite.
- 19. A component in accordance with claim 17 wherein the silane coating is the hydrolyzed product of (pentafluorophenyl)propyltrimethoxy silane.
Parent Case Info
[0001] This application claims the benefit of U.S. Provisional Application, Serial No. 60/131,013, filed Apr. 26, 1999 entitled PROCESS FOR THE STABILIZATION OF BETA-EUCRYPTITE FOR USE IN NON-HERMETIC ENVIRONMENTS, by Russell A. Crook and James E. Webb.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60131013 |
Apr 1999 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09535587 |
Mar 2000 |
US |
Child |
10087693 |
Mar 2002 |
US |