Insight into molecular dynamics behavior of glass-forming liquids from experiment and MD simulations.2023.02.13 13:26 - Katarzyna Kuźniar
At the beginning we will have a brief look at the liquid-glass transition phenomenon. However, most attention will be focused on the behavior of molecular dynamics during the vitrification process, caused by cooling and compression. Molecular dynamic behavior will be analyzed and discussed mainly in term of the density scaling idea, which was proposed to jointly describe the dependence of molecular dynamics of glass-forming liquids on thermal and packing effects. According to this idea, both isobaric and isothermal structural relaxation times or viscosity can be expressed as a single universal curve if they are plotted against new variable TVγ, where T and V denote temperature and specific volume, respectively, and γ is the scaling exponent. The core of my presentation will refer to the relationship between the scaling exponent, the steepness of the repulsive part of the intermolecular potential, and the role of molecular structure and interaction anisotropy. In the last part of my presentation, I will also show how density scaling can be applied to analyze entropy data.