1. Borosilicate glass characteristics

1.1 Glassy state

The term "glass" is applied to compounds with the property of being able to form, after melting, a non-crystalline solid that retains the structural disorder of the liquid: the material is therefore in a thermodynamically metastable state known as the "glassy state" . Two concepts follow from this: molten glass must behave viscously, and the cooling rate of the liquid must be sufficiently high to "freeze" the liquid without giving the material time to rearrange and thus crystallize. Glass...