Influence of Substrate Properties on the Dewetting Dynamics of Viscoelastic Polymer Films |
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| Authors: | Moustafa Hamieh Samer Al Akhrass Tayssir Hamieh Pascal Damman Sylvain Gabriele Thomas Vilmin |
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| Affiliation: | 1. Institut de Chimie des Surfaces et Interfaces (ICSI), CNRS , Mulhouse Cedex, France;2. Laboratoire de Chimie Analytique, Matériaux, Surfaces et Interfaces (CHAMSI), Département de Chimie, Faculté des Sciences I , Université Libanaise, Hadeth , Beyrouth, Liban;3. Institut de Chimie des Surfaces et Interfaces (ICSI), CNRS , Mulhouse Cedex, France;4. Laboratoire de Physicochimie des Polymères , Université de Mons Hainaut , Mons, Belgium;5. Laboratoire de Physico-Chimie Théorique , UMR CNRS Gulliver 7083, ESPCI, Paris Cedex, France |
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| Abstract: | We studied the dewetting process of thin polystyrene (PS) films on silicon substrates, coated with a thin, irreversibly adsorbed polydimethylsiloxane (PDMS) layer, by optical microscopy and atomic force microscopy. Besides demonstrating the exceptional potential of dewetting for a sensitive characterization of rheological properties of PS thin films, characterized by a stress-relaxation time, τ1, we focused on the influence of the frictional behaviour (energy dissipation mechanism) at the interface between the PDMS-coated silicon wafer and the PS film on the dewetting process. Our results show that the initial stages of dewetting depend sensitively on the thickness and the way the PDMS layer was adsorbed. The maximum width of the dewetting rim at τ1 increased with increasing PDMS layer thickness, which can be interpreted as an increase of the effective, velocity-dependent slippage length. Interestingly, τ1 was found to be almost independent of the substrate properties. Our results demonstrate that dewetting is a really powerful approach for rheological and frictional studies of thin polymer films. |
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| Keywords: | Dewetting Interfaces Nanorheology Nonlinear friction Thin polymer films Slippage length Viscoelasticity |
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