Glass is an inorganic mixture

Glass is the inorganic mixture fused at high temperature which solidifies on cooling but does not crystallize. It’s basic components, network formers and modifiers are present in the form of oxides in ordinary glasses.

Typical glass formers (network formers) are silica (SiO₂), boric acid (B₂O₃), Phospharic acid (P₂O₅) and, under certain circumstances, also aluminum oxide (Al₂O₃). These substances are capable of absorbing (dissolving) certain amount of metal oxide without losing their glassy character.

This means that the incorporated oxides do not particpipate as glass formers but modify certain physical properties of the glass structure as “Network modifiers”.

Glass Structure is amazing structure

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”.