Fundamentals of water repellency revealed
- Date:
- August 14, 2017
- Source:
- VTT Technical Research Centre of Finland
- Summary:
- The frictional mechanism that resists the motion of drops on inclined surfaces and when affected by wind drag has now been revealed by a team of researchers. They have also developed a theory by which sliding of drops off surfaces of different materials can be predicted. This makes it possible to systematically develop hydrophobic surfaces by modifying their base material and roughness.
- Share:
Principal Scientist of VTT Technical Research Centre of Finland, Dr. Lasse Makkonen has explained the frictional mechanism that resists the motion of drops on inclined surfaces and when affected by wind drag, and developed a theory by which sliding of drops off surfaces of different materials can be predicted. This makes it possible to systematically develop hydrophobic surfaces by modifying their base material and roughness.
Sliding of drops off surfaces affects the water repellency of clothing, visibility through wind screens in rain, and many industrial processes. Hence, wettability of materials is one of the most researched problems in the world.
A major problem has been that according to the force balance of a drop on a surface, proposed by Thomas Young in 1805, even the smallest external force should make the drop slide, but this does not happen in practice no matter how smooth the surface is.
Story Source:
Materials provided by VTT Technical Research Centre of Finland. Note: Content may be edited for style and length.
Journal Reference:
- Lasse Makkonen. A thermodynamic model of contact angle hysteresis. The Journal of Chemical Physics, 2017; 147 (6): 064703 DOI: 10.1063/1.4996912
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