Nanoscopic-Confinement Effects on Local Dynamics

Abstract
The segmental dynamics of 1.5–2.0 nm polymer films confined between parallel solid surfaces is investigated with dielectric spectroscopy in polymer/silicate intercalated nanocomposites. The confinement effect is evident by the observation of a mode, much faster than the bulk-polymer α relaxation and exhibiting much weaker temperature dependence. This is discussed in relation to either the interlayer spacing restricting the cooperative volume of the α relaxation or to the dominance of the more mobile interphase regions as predicted by simulations; the data qualitatively support the former.