Molecular dynamics of glass-forming liquids in confining geometries

Pulsed field gradient NMR and dielectric spectroscopy are applied to invest igate the rates of molecular reorientation and translation of the glass-for ming liquids propanediol and salol in porous glasses. Though there is a gen eral tendency for the confinement in the pore system to reduce both the rot ational 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 spati al confinement within the pore system excludes the formation of long-range molecular aggregates which dominate molecular dynamics in the bulk liquid.