Internal Structure of Diblock Copolymer Brushes.

ORAL

Abstract

Although diblock copolymer brushes (DCBs) have been studied due to their stimuli-responsive behavior, their internal structure has been unknown. We have resolved the internal structure of DCBs using neutron reflectivity and grazing incidence small-angle X-ray scattering (GISAXS). The internal brush structure of DCBs of polystyrene-$b$-poly(methyl acrylate) (PS-b-PMA) and PMA-$b$-PS depends strongly on the block sequence and the value of $\chi $N. For the thinnest films a model of two layers with an interfacial region of finite width provides a good description of the data. For dPS-b-PMA films that are thicker and of sufficiently asymmetric composition, a third layer must be included. The necessity of including a third layer is consistent with lateral ordering of some type in the center of the brush, as evidenced by correlation peaks in GISAXS data.

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Authors

  • Charles F. Majkrzak

    • National Institute of Standards and Technology
    • NIST - Center for Neutron Research

  • Sushil Satija

    • Center for Neutron Research, National Institutes of Standards and Technology, Gaithersburg, MD 20899
    • National Institute of Standards and Technology
    • NIST - Center for Neutron Research
    • Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899

  • Gokce Ugur

    • Department of Polymer Science, The University of Akron, Akron, OH 44325-3909

  • William J. Brittain

  • Mark D. Foster

    • Department of Polymer Science, The University of Akron, Akron, OH 44325-3909
    • Dept. of Polymer Science, The University of Akron
    • Department of Polymer Science, The University of Akron
    • University of Akron, Dept of Polymer Science
    • Department of Polymer Science, The University of Akron, Akron, OH 44325

  • Xuefa Li

  • Jin Wang

    • Experimental Facilities Division, Argonne National Laboratory, Argonne, IL 60439
    • ANL
    • Argonne National Laboratory

  • Bulent Akgun