Molecular dynamics of glass-forming liquids in confining geometries

Abstract

Pulsed field gradient NMR and dielectric spectroscopy are applied to investigate the rates of molecular reorientation and translation of the glass-forming liquids propanediol and salol in porous glasses. Though there is a general tendency for the confinement in the pore system to reduce both the rotational and translational mobility in comparison with the liquid phase, in particular cases also an enhancement of the molecular mobility is observed. As a possible explanation of this enhancement it is assumed that the spatial confinement within the pore system excludes the formation of long-range molecular aggregates which dominate molecular dynamics in the bulk liquid.