Fabrication of sintered high-silica glasses
AssigneeBell Telephone Laboratories, Incorporated
InventorsDavid W. Johnson, Jr., John B. MacChesney, Eliezer M. Rabinovich
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Abstract
High-silica glasses are formed by sintering a dried gel at temperatures below the liquidus. The gel may be formed by mixing colloidal silica particles or silica-containing liquids with appropriate liquids. Fragmentation of the gel during drying is advantageously avoided by redispersing the dried gel or sol in a liquid to yield a colloidal suspension which is then gelled, dried, and finally sintered below the liquidus.
Claims21
A method of fabricating a high-silica glass comprising;
- (a) forming a substantially alkali-free first sol of particles in a liquid, the particles comprising silica;
- (b) gelling the first sol to form a first gel;
- (c) drying substantially the first gel, to form a dried first gel;
- (d) forming particles from the dried first gel;
- (e) forming a substantially alkali-free second sol of particles in a liquid, by dispersing the previously prepared, substantially alkali-free particles provided in step (d) in a liquid;
- (f) gelling the second sol to form a second gel;
- (g) drying substantially the second gel;
- and
- (h) sintering the dried second gel to a glass at a temperature below the liquidus for the glass.
The method of claim 3 wherein the first or second gel is heated to between 750 degrees Celsius and 800 degrees Celsius.
The method of claim 5 wherein a boron doped glass is obtained by adding boron to the liquid in the form of a boron-containing solution.
Dependencies are inferred from the claim text.