Claims
- 1. The method of preparing a photoluminescent material comprising the step of (i) preparing a gel from a solution of a hydrogen silsesquioxane resin in a solvent, and heating the gel in oxygen by heating the gel to a temperature above approximately 400° C. for about two hours.
- 2. A method according to claim 1 in which the hydrogen silsesquioxane resin has a molecular weight of about 2 to 100 kilodalton.
- 3. A method according to claim 1 in which the solvent is selected from the group consisting of aromatic hydrocarbons, alkanes, ketones, cyclic polydimethylsiloxanes, esters, and ethers.
- 4. A method according to claim 3 in which the gel is prepared by dissolving or dispersing the resin in a solvent or a mixture of solvents to form the solution; and adding to the solution another solvent selected from the group consisting of water, methanol, ethanol, and isopropanol.
- 5. A method according to claim 1 in which the resin is a hydridosiloxane containing units of the formula HSi(OH)x(OR)yOz/2 wherein R is independently an organic group or a substituted organic group, which when bonded to silicon through the oxygen atom forms a hydrolyzable substituent; x is 0-2; y is 0-2; z is 1-3; and the sum of x+y+z is 3.
- 6. A method of claim 5, in which R is selected from the group consisting of alkyl, aryl and alkenyl group.
- 7. A method according to claim 1 including an additional step of (ii) further pyrolyzing the photoluminescent material prepared in (i) by heating the photoluminescent material in a different gas to a temperature above approximately 400° C. for about two hours.
- 8. A method according to claim 7 in which the different gas is ammonia or nitrous oxide.
- 9. A method according to claim 7 in which the different gas is nitrogen.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application U.S. Ser. No. 09/019,603 filed Feb. 6, 1998, now U.S. Pat. No. 6,018,002.
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