Short- and Long-Range Interactions in Thin Films of Polymer Blends in Microchannels

• Published in: Macromolecules Vol. 35; no. 8; pp. 3205 - 3212
• Main Authors: Yoo, Pil Jin, Suh, K. Y, Lee, Hong H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09-04-2002
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Structure, morphology and analysis; Surface effect; Short range interaction; Patterning; Long range interaction; Polymer blends; Butadiene polymer; Styrene polymer; Surface topography; Experimental study; Thin film
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma011602l

We present the surface structures formed under the void microchannels of an elastomeric mold when thin films of polystyrene/polybutadiene (PS/PB) blends are annealed with the mold placed on the film. Exactly opposite types of structure result under identical annealing conditions, depending only on the height difference in the as-cast thin film between the PS and PB phases. Recessed patterns form under the microchannel by long-range interactions when this height is more than 60 nm; the usual protruding patterns result in the void microchannels due to the short-range interactions of capillarity when the height is less than 40 nm. The height of fully developed meniscus of the mobile PB in solid PS is believed to be the factor that determines the type of pattern formation.