title: Dynamic wetting with viscous Newtonian and non-Newtonian fluids.
abstract: We examine various aspects of dynamic wetting with viscous Newtonian and non-Newtonian fluids. Rather than concentrating on the mechanisms that relieve the classic contact line stress singularity, we focus on the behavior in the wedge flow near the contact line which has the dominant influence on wetting with these fluids. Our experiments show that a Newtonian polymer melt composed of highly flexible molecules exhibits dynamic wetting behavior described very well by hydrodynamic models that capture the critical properties of the Newtonian wedge flow near the contact line. We find that shear thinning has a strong impact on dynamic wetting, by reducing the drag of the solid on the fluid near the contact line, while the elasticity of a Boger fluid has a weaker impact on dynamic wetting. Finally, we find that other polymeric fluids, nominally Newtonian in rheometric measurements, exhibit deviations from Newtonian dynamic wetting behavior.
authors.affiliation: Department of Physics, Carnegie Mellon University, USA. Center for Complex Fluids Engineering, Carnegie Mellon University, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Wei
authors.forename: E
authors.initials: E
authors.lastname: Rame
authors.forename: L M
authors.initials: LM
authors.lastname: Walker
authors.forename: S
authors.initials: S
authors.lastname: Garoff