Scientific and technological aspects of aqueous glasses

The physical nature of a glass, as related to stable liquid and crystalline solid phases was defined by Kauzmann in 1948. Since then, glass research has been almost exclusively confined to inorganic materials. This review aims to demonstrate that many substances, not falling into the category of classical 'materials', can be rendered into amorphous states. In particular, water itself, but also water soluble and water sensitive organic molecules, some of them biomolecules, can be rendered into supersaturated and solid solutions. New ways of studying and applying amorphisation processes have led to major advances in food and pharmaceutical processing aimed mainly at the stabilisation of labile materials. Because of their molecular similarities to water, polyhydroxy compounds are attracting particular interest as potential matrix elements in the preparation of glassy products.