The Onset of Dispersion-Driven Morphology for Freely-Standing Polymer Trilayer Films
Abstract
We have used reflected light microscopy to study the lateral morphology which self-assembles at elevated temperatures in freely-standing polymer trilayer films consisting of a polyisoprene (PI) layer capped on both sides by polystyrene (PS) layers (PS/PI/PS). Heating of the trilayer films causes the formation of a periodic, lateral morphology which is driven by the attractive dispersion interaction acting across the film. For films heated from room temperature at different constant heating rates, the lateral morphology was observed to form at a temperature that increased with increasing heating rate. To obtain a reliable measure of the onset temperature of the lateral morphology, we have calculated the average variance of the blue channel content of a series of optical microscope images collected at regular temperature increments during the heating of the films. This result can be understood quantitatively by considering the time- and temperature-dependence of Young's modulus of PS.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARU31004K