Predicting the Temperature Range of Arrhenius Crossover of Structural Relaxation in Fragile Glass-forming Liquids

Normal-to-Supercooled Liquid Transition in Molecular Glass-Formers: A Hidden Structural Transformation Fuelled by Conformational Interconversion

“…For centuries, supercooled liquids have played a vital role in science, industry, and the day-to-day life of human beings. − They develop when their chemical components fail to create crystallization nuclei below the freezing point. Consequently, the formation of supercooled liquids is often related to the manufacturing of glasses (including the molecular ones) via the vitrification process, in which progressive lowering of the temperature results in dramatic slowing down of molecular motions from nanoseconds to hundreds of seconds around the glass-transition temperature ( T g ). ,, This process takes place in both the nonergodic and ergodic dynamic domains of the ultraviscous liquid, which intersect at the crossover temperature T B . , However, well above T g and T B , there is another characteristic point at which intermolecular organization, molecular motion, and transport coefficients (e.g., diffusivity, viscosity) undergo significant changes. − These transformations delineate collectively the inflection point which is often referred to as the Arrhenius crossover. − …”