Effect Of Hydroxyl Content On Phase Separation In Sodium Silicate Glasses

The rate of phase separation in sodium silicate glasses increases as the hydroxyl content increases. This increase occurs as an increase in the growth rate during the coarsening stage for glasses exhibiting nucleation and growth. The rate of phase separation by spinodal decomposition increases due to enhanced diffusion with increasing hydroxyl content. There is no change in the miscibility limit with a doubling of the hydroxyl concentration. Although a small change in the spinodal limit was found, it is uncertain if this result is significant.