| 摘要 |
PURPOSE: Provided is a method for manufacturing doped-silica glass by extruding silica sol composed of colloidal sol and metal alkoxide hydrolyzed under acidic catalyst as a dopant. The resultant silica glass has high purity and high strength, enabling long and large-sized silica rods and tubes. CONSTITUTION: The method comprises the steps of: preparing a sol by mixing fumed silica with deionized water to be colloidal silica; hydrolyzing metal alkoxide as a dopant, diethyldiethoxy-germane, having two alkoxide groups under acidic catalyst(dilute HCl or H2SO4); mixing the sol with hydrolyzate, where a gelling agent, as ammonium fluoride, tetramethylammonium hydroxide or formamide, is added; filling an extruder with the sol; gelling by heating under 100deg.C; extruding; drying in a chamber; thermal-treating at low temperature, with HCl, He, H2 or O2 gas flowing for removing impurities in dried gel; sintering at 1400deg.C in He gas atmosphere.
|
