Predicting the changes of relaxation dynamics with various modifications of the chemical and physical structures of glass-formers

One merit of the coupling model (CM) is its relevance to experiments as demonstrated by its ability to rationalize, explain, and sometimes predict experimental data, particularly those on dynamics. It also predicts the changes of relaxation dynamics with various modifications of the chemical and physical structures of glass-formers. The modifications considered include application of pressure, nano-confinement, crosslinking, copolymerization, mixing with another glass-former, and various changes including molecular structure, tacticity, and molecular weight. The relaxation dynamics addressed include the secondary Johari-Goldstein β-relaxation, and the primary structural α-relaxation, and also the chain modes in the case of polymers. The changes of these relaxation mechanisms and their relations to each other with modification of chemical and physical structures are predicted and the predictions compare favorably with experimental data.