Glasses – Properties and applications

Thanks to improvements in oxide glass manufacturing techniques and changes in composition, the range of applications for this material has expanded over the centuries. The emergence of families of chalcogenide, fluoride and metallic glasses further extends the potential of these extraordinary materials.

Glass has remarkable thermo-mechanical properties. It is easy to shape (hollow glass, flat glass, fiber or microbead). Its appreciable hardness ensures excellent surface finish and polishability. Only very hard materials can scratch its surface. Glass is, however, a brittle material, but specific treatments can increase its resistance under stress and minimize the effects of breakage. By controlling the partial recrystallization of certain glasses, it is possible to obtain transparent glass-ceramics with mechanical properties far superior to those of the parent glass.

Glass is a watertight material with good chemical durability, and is therefore widely used for packaging liquids, as well as for waste containment (radioactive waste, for example). Thanks to its transparency and color, it is also an element of modern architecture. By modifying its surface by depositing layers, new chemical or optical functions can be obtained (hydrophobic, self-cleaning, anti-reflective, thermal insulation, etc.).

It is possible to continuously vary the optical properties of lenses by modifying their composition, and also to predict the value of these properties on the basis of simple empirical relationships. In this way, vision defects and chromatic aberrations can be corrected by choosing the right lenses. The principle of light propagation in an optical fiber or planar guide has enabled the development of modern telecommunications networks and lasers. Infrared-transparent chalcogenide lenses have enabled the development of night-time imaging devices and highly selective chemical and biochemical sensors.

The aim of this article is to provide essential information on the composition and various properties of glass materials. It describes the evolution of manufacturing processes and the search for new functional glasses in response to expectations in the fields of energy, optics and sustainable development.

This article follows on from [AF 3600] "Theoretical aspects".

A table of acronyms is provided at the end of the article.