Spontaneous Planarization of Nanoscale Phase Separated Thin Film

Authors

• Ravi F. Saraf, University of Nebraska-LincolnFollow
• Sanjun Niu, University of Nebraska-LincolnFollow
• Eric Stumb, Virginia Polytechnic Institute and State University

Date of this Version

6-10-2002

Comments

Originally published in June 2002 in Applied Physics Letters 80(23). and may be found at the publisher's site: http://ojps.aip.org/aplo/aplcr.jsp, DOI: 10.1063/1.1481187 © Copyright 2002 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Abstract

Structure of complex fluid at mesoscales is influenced by interfacial effects. We describe the dynamic response in such films to sudden change in interfacial tension. In a self-assembled block copolymer film, the monolayer of 15 nm diam cylindrical discrete phases close to the surface commence to sink at an average rate of 0.16 nm/day in response to the interfacial tension change. Surprisingly, this spontaneous planarization occurs, even though the cylinders are covalently stitched to the matrix. A simple model explains the observed behavior. The observation may lead to approaches to tailor the structure of mesoscale thin films of complex fluids for long-range order that are desirable for nanoscale device fabrication.