Hindered Diffusion of an Oil Drop Under Confinement and Surface Forces
Hannah Lockie, Scott McLean, Raymond R Dagastine
JOURNAL OF PHYSICAL CHEMISTRY LETTERS | AMER CHEMICAL SOC | Published : 2011
Theoretical modeling of coalescence and drop-drop collision stability relies on an accurate physical understanding of surface forces, hydrodynamic drainage behavior, deformation, and internal drop flow. Brownian diffusion of alkane drops emulsified in aqueous solutions above a silica plate is measured using the total internal reflection microscope (TIRM). The behavior of drops over a range of separations is consistent with an immobile oil-water interface in both clean and anionic surfactant systems, counter to the hydro-dynamic boundary conditions commonly assumed for fluid-fluid interfaces.
We thank Derek Y. C. Chan and Franz Grieser for useful discussions, the Australian Research Council for financial support and the Particulate Fluids Processing Centre for infrastructure support.