Capillary Levelling of Cylindrical Holes in Freestanding Polymer Films

ORAL

Abstract

Studying nano-scale flow in thin viscous films is of both practical and theoretical interest, particularly when considering the role of the hydrodynamic boundary conditions. Here, thin bilayer polystyrene films were prepared freestanding in air, with one of the two films having micrometer scale cylindrical holes. Because of the free interfaces, such films flow without interfacial friction at either surface. The viscoelastic relaxation of the holes was studied using atomic force microscopy. The temporal evolution of the holes shows three distinct regimes: an early time regime where the film undergoes an elastic response; an intermediate regime where the hole undergoes viscoelastic symmetrization to equilibrate internal Laplace pressure; and a late time regime where the film undergoes capillary driven flow.

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Authors

  • John Niven

    McMaster University

  • Paul Fowler

    McMaster University

  • Thomas Salez

    ESPCI, Laboratoire de Physico-Chimie Theorique, UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 75005 Paris, France

  • Howard Stone

    Princeton University

  • Elie Raphael

    ESPCI Paris, ESPCI, Laboratoire de Physico-Chimie Theorique, UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 75005 Paris, France

  • Kari Dalnoki-Veress

    McMaster University, Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada, L8S 4M1, Department of Physics & Astronomy, McMaster University, Hamilton, Canada