11: Water in Glasses and Melts

All oxide glasses contain chemically bound water, usually in the form of hydroxyl. The effects of water content on the infrared spectrum, glass transformation temperature, and melt viscosity are very important in a number of commercial applications. Variations in the reported values for T_g of glasses of supposedly the same composition are probably due to variations in water content, which should be specified in any work dealing with the properties which are particularly sensitive to water concentration.