An approach to new glasses through phase separation

The application of liquid-liquid phase separation to the preparation of new glasses has been demonstrated. The in situ observation of phase separation has been made on some berate liquids at 1-g (g = gravitational field at Ea rth's surface) and under microgravity circumstances (drop tests) to estimat e rates of phase separation. The liquid-liquid phase separation of barium b erate liquids resulted in the precipitation of droplets of several tens of a micrometer in diameter, which was assumed to be applicable for the prepar ation of glass spheres, lens array, etc. The addition of rare earth oxide t o the systems resulted in enriching the rare earth content of the precipita ted droplets, indicating that the composition of the droplets would be modi fied by adding another oxide to melts. The microgravity circumstances decre ased the phase separation rates and were found to be favorable for the prep aration of glass spheres. (C) 1999 Published by Elsevier Science B.V. All r ights reserved.