Self-Organization of PS-b-PFOMA Block Copolymer Aggregates in Thin Films

ORAL

Abstract

SFM, STEM and XPS were employed to study the morphologies of polystyrene-b-poly(1,1',2,2'-tetrahydroperflurooctyl methacrylate) (PS-b-PFOMA) films. The copolymer was dissolved in the co-solvent mixture of Freon 113 and toluene. Upon spin-casting on Si/SiOx substrate, PS-b-PFOMA was found to self-organize into spherical aggregates, where the cores of the spheres were composed primarily of PFOMA and the matrix was composed by PS. However, exposing the films to supercritical CO$_{2}$ led to a reversed morphology, where spheres of PS were embedded in the matrix of PFOMA. In addition, the degree of ordering was improved in sc-CO$_{2}$ and the domain size was tuned by adjusting sc-CO$_{2}$ density. The results were discussed based on the effects of sc-CO$_{2}$ on the interfacial tension and the relative PS-PFOMA interactions.

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Authors

  • Yuan Li

  • Luciana Meli

  • Keith Johnston

    • Graduate Program of Materials Science and Engineering, Department of Chemical Engineering, The University of Texas at Austin

  • Kwon Lim

    • Division of Image and Information Engineering, Pukyong National University, Korea

  • Peter Green

    • Department of Material Science and Engineering, Applied Physics, Macromolecular Science and Engineering, University of Michigan
    • Department of Materials Science and Engineering, University of Michigan
    • Department of Materials Science and Engineering, The University of Michigan