Synthesis of High Quality and High Transparency Quartz Glass Using Sodium Metasilicate and Quaternary Ammonium Salt as Raw Materials

Abstract

Synthesis of high quality quartz glass was accomplished by the thermal decomposition of a quaternary ammonium silicate about 1000 °C. Quaternary ammonium silicate was prepared at room temperature in a Yield of 65% by adding 1 mol quaternary ammonium salt to a 0.5 m ol/1 of sodium metasilicate aqueous solution, with adjusting pH to 11.8 by the addition of 0.01 mol HC1.
It was con sidered that the reaction proceeds according to the following expressions ( 1 ) and ( 2 ).
Na₂SiO₃ + 2[(CH₃)₄N]Cl_??_ [(CH₃)₄N]₂SiO₃+2 NaCl ( 1 )
[(CH₃)₄N]₂SiO₃+31/2O₂_??_ SiO₂ +8CO₂+2NO₂ + 12H₂O( 2 )