69th Annual Meeting of the APS Division of Fluid Dynamics (Nov 20 — 22, 2016)

P0026: Interfacial "flowers" generated during dewetting of alkane films on aqueous solutions

Authors

• Jie Feng, Department of Mechanical and Aerospace Engineering, Princeton University
• Orest Shardt, Department of Mechanical and Aerospace Engineering, Princeton University
• Howard A. Stone, Department of Mechanical and Aerospace Engineering, Princeton University

DOI: https://doi.org/10.1103/APS.DFD.2016.GFM.P0026

When a small quantity of a linear alkane is deposited on the surface of an aqueous solution containing surfactants or polymers, it initially spreads, forming a thin film that later dewets. Dewetting starts with the nucleation of multiple holes in the oil film and proceeds with the growth of oil ridges around the expanding holes. These ridges undergo a Rayleigh-like instability, forming intricate petal-like patterns. Observed under a digital camera and confocal microscope, these films with growing holes resemble gardens of interfacial flowers. Experiments with different alkanes and varying concentrations of polymers and surfactants show that the substrate viscosity and interfacial tensions determine the growth rates of the holes, the eventual instability, and the structure of the flowers.