Slip-Mediated Dewetting of Polymer Microdroplets

Abstract

Classical hydrodynamic models predict that infinite work is required to move a three-phase contact line, defined here as the line where a liquid/vapor interface intersects a solid surface. Assuming a slip boundary condition, in which the liquid slides against the solid, such an unphysical prediction is avoided. In this article, we present the results of experiments in which a contact line moves and where slip is a dominating and controllable factor. Spherical cap shaped polystyrene microdroplets, with non-equilibrium contact angle, are placed on solid self-assembled monolayer coatings from which they dewet. The relaxation is monitored using \textit{in situ} atomic force microscopy. We find that slip has a strong influence on the droplet evolutions, both on the transient non-spherical shapes and contact line dynamics. The observations are in agreement with scaling analysis and boundary element numerical integration of the governing Stokes equations, including a Navier slip boundary condition.

19 pages, 4 figures + 6 figures in supporting information

References in corpus (4)

• Influence of Slip on the Plateau-Rayleigh Instability on a Fibre
• Liquid meniscus friction on a wet plate: Bubbles, lamellae and foams
• Thermal noise influences fluid flow in thin films during spinodal dewetting
• A comparison of slip, disjoining pressure, and interface formation models for contact line motion through asymptotic analysis of thin two-dimensional droplet spreading

Cited by in corpus (9)

• Comparison of the slip of a PDMS melt on weakly adsorbing surfaces measured by a new photobleaching-based technique
• Steering droplets on substrates using moving steps in wettability
• Capillary Levelling of Immiscible Bilayer Films
• Near-critical spreading of droplets
• Slip and friction mechanisms at polymer semi-dilute solutions / solid interfaces
• Droplets on substrates with oscillating wettability
• Hydrodynamic density-functional theory for the moving contact-line problem reveals fluid structure and emergence of a spatially distinct pattern
• Effects of slippage on the dewetting of a droplet
• Film deposition of a self-propelled droplet on a cone with slip