Molecular Dynamics of Liquids in Confinement

Abstract

Surface and confinement effects may have substantial effects on the molecular and collective dynamics of liquids. Within this chapter, we describe the confinement effects on the dynamical modes of isotropic liquids. Characteristic for many systems is the formation of surface layers with a retarded dynamics. Proper treatment of the adsorber walls (“lubrication”) can reduce or completely remove such layers. In glass-forming liquids, the limiting space can lead to the suppression of the formation of collectively reorienting clusters in the liquid, and consequently to an acceleration of the dynamics compared to the bulk liquid. The combination of retarding and accelerating effects in a system where molecular migration between the boundary layers and the core is effective is describes in a dynamic model that calculates the influences of molecular exchange on dielectric spectra.