Atom Delocalization and Fluctuation Hole Formation in Amorphous Organic Polymers and Inorganic Glasses

Abstract

A viewpoint is developed that formation of a hole in amorphous substances corresponds to the atom delocalization process, i.e., its fluctuation limiting shift from the temporary equilibrium state. The molecular-kinetic processes proceeding in liquids and amorphous rigid solids do not depend on the classical van der Waals free volume, “void statistical space between atoms,” but mainly depend on the fluctuation dynamic free volume, which coincides with the fluctuation free volume caused by the atom delocalization. The atom delocalization process (local configuration structural change) plays the key role in the viscous flow of glass-forming liquids. The softening of glasses (at Tg) and their frozen reversible deformation (at 20°C) are characterized by the same molecular mechanism, namely, the atom delocalization. From the same positions as noted above, the effect of plasticity of inorganic glasses and amorphous organic polymers was considered.