Crystallization and vitrification of ethanol at high pressures

J Chem Phys. 2014 Nov 21;141(19):194504. doi: 10.1063/1.4902059.

Abstract

We present the high pressure (up to 3 GPa) dielectric spectroscopy study of ethanol in supercooled liquid and solid states. It was found that ethanol can be obtained in the glassy form by relatively slow cooling in the pressure range below 1.5 GPa. Glassy dynamics of ethanol is dominated by hydrogen bonds which cause rise of fragility index with pressure rising and relatively slow increase of glassification temperature. The termination of ethanol galssification at 1.5 GPa is related to the phase transition of ethanol in this pressure range to the disordered crystal structure which allows easy crystallization of ethanol at high pressures. Dielectric spectroscopy of solid phases of ethanol reveals the presence of molecular motion in both of them in the temperature range close to the melting curve but demonstrates different molecular dynamics in the two solid phases of ethanol.