All standard theories and models of glass transition appear to be inadequate: missing some essential physics

Abstract

Many-molecule relaxation dynamics manifest themselves as general properties of the structural α-relaxation of glass-forming liquids independent of chemical composition and physical structure. An example is the Kohlrausch stretched exponential correlation function, ɸ(t) = exp[−(t/τa)1−n], where 0≤n<1 is a convenient measure of the dispersion of the α-relaxation and the extent of the many-molecule relaxation dynamics. Plenty of the other general properties are shown to be either governed by n or correlated with n, and these empirical facts collectively indicate the importance of many-molecule relaxation dynamics. Practically, all standard theories and models of glass transition have not taken many-molecule relaxation dynamics adequately into consideration and it is unsurprising that they cannot explain some of the general properties. Furthermore, they only address the structural α-relaxation without considering the universal Johari-Goldstein secondary relaxation and the role it plays as the precursor of the many-molecule relaxation dynamics. Experiments have shown that the Johari-Goldstein relaxation has properties that mimic the Its relaxation time τJG bears a general relation to τα, which is governed by n. These general properties of the Johari-Goldstein relaxation indicate its fundamental importance, which is not recognized or considered in all standard theories and models. Thus, we conclude that all standard theories and models of glass transition are inadequate.