Glass Transition in Liquids: Two versus Three-Dimensional Confinement

The molecular dynamics of glass-forming liquids is strongly affected by nm-scale confinements. Our dielectric data provide strong evidence both for the “cooperativity” concept and for the existence of two states (interfacial layer and volume liquid). With decreasing size of confinement the orientational relaxation associated with the glass transition becomes faster, and the glass transition temperature is lowered. These effects are stronger for 3D confined droplets than for 2D confined pores. However, the radius at which size effects cease, i.e., the cooperativity length, does not depend on the dimensionality of the confinement.