COLL 512 |
| Warren T. Ford1, Dongqi Qin1, Susheng Tan1, Sarah H. Tolbert2, and Alessandro Rugge2. (1) Department of Chemistry, Oklahoma State University, Stillwater, OK 74078, (2) Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095 |
| Copolymer latexes composed of 90-95% styrene and 5-10% 2-hydroxyethyl methacrylate (HEMA) in aqueous dispersions deposit by evaporation of water as multilayered films of fcc colloidal crystals on glass with hexagonal layers parallel to the film plane. Absorption of vapors of styrene or toluene into the film followed by evaporation, with no change in mass of the film, transforms the morphology to a interconnected colloidal array (ICA) with hexagonally ordered holes in the surface. AFM and absorption spectroscopic observations of the transformation process show an order-disorder-order sequence of structures. Thicknesses of the films and XPS and contact angle measurements indicate that the vapor absorption collapses the film, and the surface transforms from polyHEMA-rich to polystyrene-rich. TEM and SEM images of the transformed films show that periodic order is retained in the ICA. The mechanism of this unusual transformation of polymer morphology will be discussed. |
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Symposium in Memory of Arthur W. Adamson
2:00 PM-5:20 PM, Thursday, April 1, 2004 Marriott -- Orange County 3, Oral
Division of Colloid and Surface Chemistry |