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Published on: May 15, 2017
Contact line motion on nanorough surfaces: a thermally activated process
Melanie Ramiasa1, John Ralston, Renate Fetzer
1Ian Wark Research Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
Journal of the American Chemical Society
|April 24, 2013
Summary
Investigating solid-liquid-liquid contact line motion on nanorough surfaces reveals that pinning-depinning events are crucial. Surface topography and wettability directly influence wetting activation free energy and contact line dynamics.
Area of Science:
- Physics
- Materials Science
- Surface Science
Background:
- The motion of contact lines is fundamental to many physical and chemical processes.
- Understanding contact line dynamics on nanorough surfaces is challenging due to complex interactions.
Purpose of the Study:
- To investigate the motion of solid-liquid-liquid contact lines over surfaces with varying nanodefects.
- To determine the mechanisms governing thermally activated contact line motion on nanorough substrates.
- To evaluate the influence of surface nanotopography on wetting activation energy and contact line friction.
Main Methods:
- Experimental investigation of contact line motion on nanorough surfaces with controlled nanodefects.
- Analysis using molecular kinetic theory and a derivation for hysteresis energy based on the Joanny and de Gennes model.
- Evaluation of the impact of nanotopographical features on wetting activation free energy and contact line friction.
Main Results:
- Contact line motion on nanorough surfaces is thermally activated but not solely explained by molecular kinetic theory.
- Thermally activated pinning-depinning events at surface nanodefects are significant.
- Wetting activation free energy is influenced by both solid-liquid interactions and surface pinning strength.
Conclusions:
- Surface nanotopography plays a critical role in contact line motion dynamics.
- For low nanodefect densities, wetting activation free energy is a sum of wettability and topography contributions.
- A direct link is established between contact line dynamics and surface roughness parameters.
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