WIAS Preprint No. 2538, (2018)

Signatures of slip in dewetting polymer films


Authors

  • Peschka, Dirk
    ORCID: 0000-0002-3047-1140
  • Haefner, Sabrina
  • Jacobs, Karin
  • Münch, Andreas
  • Wagner, Barbara
    ORCID: 0000-0001-8306-3645

2010 Mathematics Subject Classification

  • 76A20 35B36 65M50 65M60

Keywords

  • Thin fluid films, pattern formation, finite elements, local mesh refinement

DOI

10.20347/WIAS.PREPRINT.2538

Abstract

Thin liquid polymer films on hydrophobic substrates are susceptable to rupture and formation of holes, which in turn initiate a complex dewetting process that eventually evolves into characteristic stationary droplet patterns. Experimental and theoretical studies suggest that the specific type of droplet pattern largely depends on the nature of the polymer-substrate boundary condition. To follow the morphological evolution numerically over long time scales and for the multiple length scales involved has so far been a major challenge. In this study a highly adaptive finite-element based numerical scheme is presented that allows for large-scale simulations to follow the evolution of the dewetting process deep into the nonlinear regime of the model equations, capturing the complex dynamics including shedding of droplets. In addition, the numerical results predict the previouly unknown shedding of satellite droplets during the destabilisation of liquid ridges, that form during the late stages of the dewetting process. While the formation of satellite droplets is well-known in the context of elongating fluid filaments and jets, we show here that for dewetting liquid ridges this property can be dramatically altered by the interfacial condition between polymer and substrate, namely slip.

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