The Structon Theory of Glasses and Solutions

In sodium silicate glasses and in many liquid solutions, curves representing the dependence of various properties on composition show distinct breaks. This behavior can be reasonably interpreted in terms of the types of environment around each atom or molecule or atomic group responsible for strong intermolecular interactions, together with the assumption that in these systems only the most stable environments are present in significant amounts. Only closest neighbors need be considered, hence the types of environment can conveniently be described in terms of “ structons,” each structon type being defined as a given kind of atom (or molecule or atomic group) surrounded by close neighbors in a given way. The compositions at the breaks in the property curves limit, and in some cases determine uniquely, the types of structon present in and between the different composition ranges. The structon theory has been applied to sodium silicate glasses and certain liquid solutions, in which there are strong hydrogen-bond interactions between molecules.