Solid-Like Dynamics in Ultrathin Films of Polymeric Liquids

摘要

In this letter, we demonstrate that, at mesoscales, nonferroelectric liquid films of polydimethyl siloxane. exhibit significant electrostriction not present in the corresponding bulk state. Remarkably, the observed electrostrictive effect has a response time ,20 ms in contrast to .5 ms recorded in conventional bulk ~ferroelectric polymers. The emergence of this fast electrostrictive strain in thin films is explained in terms of the amalgamation of two contrasting dynamic features—the influence of a highly mobile, viscous layer ~at the air/film interface. on the less-mobile, but fast responding, solid-like layer at the film/substrate interface. The effect is observed for thickness below 200 nm.