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Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
Nanohydrodynamics: the intrinsic flow boundary condition on smooth surfaces
Cécile Cottin-Bizonne1, Audrey Steinberger, Benjamin Cross
1Université de Lyon, Lyon, France.
Langmuir : the ACS Journal of Surfaces and Colloids
|February 13, 2008
Summary
This study reveals that water exhibits slip on hydrophobic surfaces, while no-slip conditions prevail on wetting surfaces. Liquid viscosity and surface hydrophobicity significantly influence flow boundary conditions.
Area of Science:
- Fluid dynamics
- Surface science
- Tribology
Background:
- Understanding liquid behavior at interfaces is crucial for microfluidics and material design.
- The no-slip boundary condition is a common assumption, but slip can occur under specific circumstances.
- Quantifying slip length accurately requires careful consideration of experimental factors.
Purpose of the Study:
- To determine the intrinsic flow boundary conditions of water and dodecane on various surfaces.
- To investigate the impact of experimental errors and data analysis on slip length accuracy.
- To explore the influence of hydrophobicity and liquid viscosity on boundary flow.
Main Methods:
- Utilizing a dynamic surface force apparatus to measure flow boundary conditions.
- Investigating simple liquids like water and dodecane on smooth surfaces.
- Employing water-glycerol mixtures to vary viscosity while maintaining similar wetting properties.
Main Results:
- A no-slip boundary condition was observed in all wetting scenarios.
- Water demonstrated finite slippage on strongly hydrophobic surfaces, increasing with hydrophobicity.
- Dissipation was consistently described by a well-defined boundary condition across various conditions.
Conclusions:
- The study confirms no-slip for wetting surfaces and slip for hydrophobic surfaces.
- Hydrophobicity is a key factor driving slip, more so than viscosity in some cases.
- Accurate slip length determination necessitates rigorous error analysis and understanding of boundary conditions.
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