Force response of actively deformed polymer microdroplets: dependence on the solid/liquid boundary condition

ORAL

Abstract

In fluid dynamics, the solid/liquid boundary condition can play a major role in the flow behavior of a liquid. For example, in the dewetting of identical polymer films on weak slip or strong slip substrates, large qualitative and quantitative differences are observed. Therefore, when applying an external load to a liquid resting on such substrates, the measured reaction forces and the ensuing flow should also depend on the boundary condition. We present atomic force microscopy measurements in which the reaction force of a cantilever is measured as the tip pierces liquid polymer micron sized droplets and films. These indentations are done on substrates with tuned slip. Accessing the size, depth and rate dependence of the resulting force distance curves, we show an influence of the slip condition on the dissipated energy and adhesion.

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Authors

  • Jonas Heppe

    INM - Leibniz Institute for New Materials and Saarland University, Experimental Physics, D-66123, Saarbruecken, Germany

  • Joshua D. McGraw

    Saarland University, Experimental Physics, D-66041 Saarbruecken, Germany, Saarland University, Saarland University, Experimental Physics, 66041 Saarbr\"ucken, Saarland University, Experimental Physics, D-66123, Saarbruecken, Germany

  • Roland Bennewitz

    INM - Leibniz Institute for New Materials, D-66123, Saarbruecken, Germany

  • Karin Jacobs

    Saarland University, Experimental Physics, D-66041 Saarbruecken, Germany, Saarland University, Experimental Physics, D-66123 Saarbr\"ucken, Experimental Physics, Saarland University, Saarbr\"ucken, Germany, Saarland University, Saarland University, Experimental Physics, 66041 Saarbr\"ucken, Experimental Physics, Saarland University, Saarbruecken, Germany, Saarland University, Experimental Physics and INM, D-66123, Saarbruecken, Germany