A large number of chemical substances solidify from the liquid state of melt in the form of glass. The glass formation depends on the cooling rate and requires mixed types of bonding (covalent bond and ionic bond) between the atom groups.
As a result, glass forming products have a strong tendency while still in the melt for three-dimensional arrangement in what is known as a “Crystal lattice”, as soon as the particular substance changes from the liquid to the solid state. Glass, however, on cooling from the liquid state, forms a largely spatially random “network”. The main components which participate in the glass formation are therefore called “network forms”.
Ions can be incorporated in this network of glass-forming molecules, as a result of which they tear up network in certain places and modify the network structure and thus glass properties. That is why they are called “network modifiers”.
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