Vitrification

Vitrification (from Latin vitreum, "glass" via French vitrifier) is the transformation of a substance into a glass. Usually, it is achieved by rapidly cooling a liquid through the glass transition. Certain chemical reactions also result in glasses. An important application is the vitrification of an antifreeze-like liquid in cryopreservation.

Vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles (atoms, molecules, forming blocks) becomes higher than a certain threshold value. Thermal fluctuations break the bonds; therefore, the lower the temperature, the higher the degree of connectivity. Because of that amorphous materials have a characteristic threshold temperature termed glass transition temperature (T_g): below T_g amorphous materials are glassy whereas above T_g they are molten.

In a wider sense, the embedding of material in a glassy matrix is also called vitrification. An important application is the vitrification of radioactive waste to obtain a stable compound that is suitable for ultimate disposal.