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Kinetic viscoelasticity during early polymer-polymer spinodal dewetting

ORAL

Abstract

 The dewetting kinetics of a supported polymer bilayer were measured in-situ using coherent

grazing incidence x-ray scattering. X-ray photon correlation spectroscopy (XPCS) provides both

the two-time correlation functions and the cross-correlation function which measures the average

spatial shift of the speckles produced by the coherent x-rays. The stress in the ultra-thin dewetting top film can be directly observed due to exquisite sensitivity to sample curvature changes provided by the x-ray speckle correlation functions. The hole opening events in the film are found to be associated with significant changes to the stress. These results are interpreted through an analogy between viscoelastic spinodal dewetting and early-stage bulk viscoelastic phase separation. The frequency of hole initiation events during dewetting decreases with time as a power law, the power-law exponent can be linked to non-linear viscoelastic effects; showing similarity in their stress relief dynamics to aftershock decays.

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Publication: [1]J. Lal, L. B. Lurio , D. Liang, S. Narayanan, S. B. Darling and M. Sutton, "Kinetic viscoelasticity during early polymer-polymer spinodal dewetting" (submitted to PRR 2021).<br>[2] J. Lal, L. B. Lurio, D. Liang, S. Narayanan, S. B. Darling, and M. Sutton, Universal dynamics of coarsening during polymer-polymer thin-film spinodal dewetting kinetics, Phys. Rev. E 102, 032802 (2020).<br>[3] Lal, J. et al. Dewetting in immiscible polymer bilayer films. Phys. Rev. Materials 1, 015601, DOI: 10.1103/<br>Phys. Rev. Materials.1.015601 (2017).

Presenters

  • Jyotsana Lal

    MSD, Argonne National Laboratory/Northern Illinois University, Argonne National Lab./Northern Illinois University

Authors

  • Jyotsana Lal

    MSD, Argonne National Laboratory/Northern Illinois University, Argonne National Lab./Northern Illinois University

  • Larry B Lurio

    Department of Physics, Northern Illinois University, DeKalb, IL 60115, USA, Northern Illinois University

  • Dennis Liang

    IPNS, Argonne National Laboratory

  • Suresh Narayanan

    Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory, XSD, Argonne National Laboratory, Advanced Photon Source, Argonne National Lab

  • Seth B Darling

    CSE, Argonne National Laboratory, Argonne, IL 60439, USA

  • Mark D Sutton

    Physics Department, McGill University, Montreal, H3A 2T8, Canada, McGill University, Department of Physics, Department of Physics, McGill University