Nanoconfinement and the glass transition: a cluster hypothesis

It is suggested that the depression of the glass temperature in nanoconfined liquids and polymers may be explained by an effect of the confinement alone: specifically, confinement by hard walls creates an excluded volume effect that decreases the fraction of molecules organized in clusters. If we think of this fraction as a rough surrogate determining the fictive or structural temperature, then the confined liquid will have a higher fictive temperature than the bulk liquid at the same actual temperature. A computational method already used to study clusters may test the hypothesis.