Surface Dynamics Of Homopolymer Brushes

POSTER

Abstract

The surface dynamics of polystyrene (PS) and poly($n$-butyl acrylate) (P$n$BA) homopolymer brushes were investigated by X-ray photon correlation spectroscopy for the first time. Within the range of time (0.2 -1100 s) and length scale (0.2-5 um) studied, no fluctuations of the brush surfaces were detectable. When PS brushes of thicknesses in the range of 9-101 nm and high grafting density ($>$0.5 chains/nm\^{}2) were considered at temperatures up to Tg+130C, no relaxation was visible within our window of in-plane wave-vector. Even reduction of the grafting density from 0.6 to 0.1 chains/nm\^{}2 did not bring the relaxation into the window. Likewise, no relaxation was observed for P$n$BA brushes up to 170C above Tg. The suppression of surface fluctuations is a result of covalent tethering.

Authors

  • Gokce Ugur

    • The University of Akron, Akron, OH 44325-3909

  • Bulent Akgun

    • The University of Akron, Akron, OH 44325-3909
    • NIST Center for Neutron Research/ Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742

  • Zhang Jiang

    • X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439

  • Suresh Narayanan

    • X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439

  • Sanghoon Song

    • Department of Physics and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea

  • Heegu Lee

    • Department of Physics and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea

  • William J. Brittain

    • The University of Akron, Akron, OH 44325-3909

  • Hyunjung Kim

    • Department of Physics and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea

  • Sunil K. Sinha

    • Department of Physics, University of California San Diego, La Jolla, CA 92093

  • Mark D. Foster

    • The University of Akron, Akron, OH 44325-3909