Report

Glassy Dynamics in Condensed Isolated Polymer Chains

See allHide authors and affiliations

Science  20 Sep 2013:
Vol. 341, Issue 6152, pp. 1371-1374
DOI: 10.1126/science.1238950

You are currently viewing the abstract.

View Full Text

Polymer Dynamics

While free surfaces should allow polymer chains to move faster than in the bulk, the presence of a substrate might slow down the motion if there is an attraction between the two. Tress et al. (p. 1371; see the Perspective by Russell) used dielectric spectroscopy to study “polymer islands” deposited on a substrate from dilute solution, where some islands contained just a few or only one polymer chain. The confinement of the polymer chain to small-surface geometries had virtually no influence on the dynamics of the polymers, aside from the segments in direct contact with the substrate.

Abstract

In the course of miniaturization down to the nanometer scale, much remains unknown concerning how and to what extent the properties of materials are changed. To learn more about the dynamics of condensed isolated polymer chains, we used broadband dielectric spectroscopy and a capacitor with nanostructured electrodes separated by 35 nanometers. We measured the dynamic glass transition of poly(2-vinylpyridine) and found it to be bulk-like; only segments closer than 0.5 nanometer to the substrate were weakly slowed. Our approach paves the way for numerous experiments on the dynamics of isolated molecules.

View Full Text