Molecular Dynamics in Confining Space

The molecular and collective dynamics in confining space is determined by the counter balance between surface- and confinement effects [1]. The former results from interactions of a host system with guest molecules which take place at the interface between both, the latter originates from the inherent length scale on which the underlying molecular fluctuations take place. Surface effects cause a decrease while confinement effects are characterised by an increase of the molecular dynamics with decreasing spatial dimensions of the confining space (Fig.6.1). Hence in glass-forming systems [2–7]for the calorimetric glass transition temperature an increase resp. a decrease is observed. It is evident that this counterbalance must depend sensitively on the type of confined molecules (glass-forming liquids, polymers, liquid crystals), on the properties of the (inner) surfaces (wetting, non-wetting) and on the architecture of the molecules with respect to the walls (grafted, layered or amorphous systems).