Anomalous phase separation behavior of gel-derived soda-silica glassesThe effects of retained bound hydroxyl groups on amorphous immiscibility behavior and on the kinetics of phase separation were studied in glasses containing from 10 to 19 percent sodium oxide preparaed by the gel process. Differences in behavior as functions of preliminary thermal treatment of the gel precursor and of melting conditions were studied, employing IR spectroscopy, SAXS and WAXD to monitor the variation in glass microstructure. Both the initial gel treatment and the OH concentration in the prepared glasses were found to affect the immiscibility temperatures, and the magnitude of the maximum temperature increase was also a function of the sodium oxide concentration. It is suggested that the variation in thermodynamic behavior may be caused by the structural arrangement attained by the OH groups during the gel condensation process, which in turn affects the extent of hydrogen bonding to nonbridging oxygen ions.
Document ID
19830062071
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Neilson, G. F. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Weinberg, M. C. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena CA, United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1982
Subject Category
Nonmetallic Materials
Meeting Information
Meeting: Materials processing in the reduced gravity environment of space; Annual Meeting