Density scaling and isodynes in glycerol–water mixtures†

Abstract

This paper presents dielectric and neutron spectroscopy data on two different glycerol–water mixtures at elevated pressures. Glycerol–water liquid mixtures have a high concentration of hydrogen bonds which usually is expected to lead to complex dynamics. However, with regard to the pressure dependence of the dynamics we reveal a surprisingly simple picture. Different aspects of the dynamics have the same pressure dependence, in other words the phase diagram of the liquids have so-called isodynes, density scaling is also observed to hold reasonably well and there is even some reminiscence of isochronal superposition. This suggests that these aspect of liquid dynamics are very general and hold for different types of intermolecular interactions.