TABLE OF CONTENTS Although not normally discussed as a component of individual glasses, it should be recognized that all glasses contain chemically bound water. This water can occur in the form of hydroxyl bonded to the basic building blocks of the structure, or as molecular water dispersed in the interstices of the network. The concentration of water can range from parts per billion for the best vitreous silica optical fiber, to hundreds of parts per million for typical commercial glasses, to many percent for glasses found in nature. The presence of water is easily detected in the infrared spectra of glasses.
Since water has a larger effect on some properties of glasses per unit of concentration than any other component, it deserves discussion as a separate chapter of this book. This chapter will first discuss the spectral detection of water in glasses and the methods used to vary the water content of glasses. The next section of the chapter will consider the experimental methods for measuring diffusion and solubility of water in glasses and melts, and the effect of composition and other factors on the results. The final portion of the chapter will present data illustrating the large effect of water on certain properties of glasses.
The presence of hydroxyl and molecular water in glasses is detected by measurement of the infrared spectrum between 2000 and 4000 cm -1. While there is considerable controversy regarding the cause of specific absorption bands, it...
