Breaking Bad: symmetric soap films choose chaos
I submitted the above image for the National Science Foundations (NSF) VIZZIES competition (2015). Watch the video below and read the description to learn something interesting about the Marangoni effect in surfactant bubbles.
Abstract: The images depict the thin film dynamics of a surfactant-laden film (Dipalmitoylphosphatidylcholine, a pulmonary surfactant). This film is captured by elevating a bubble (in a surfactant solution) towards the air-liquid interface. This thin film drains under the influence of gravity, until it reaches a critical thickness and spontaneously ruptures. Using a color camera and white light, the evolution of the color fringes are recorded. The color fringes directly relate to the thickness of the film. These surface flows can be used to infer the properties of the air liquid interface. For e.g. a viscoelastic surface would produces an immobile interface (tear film, lung surfactants show this behaviour), whereas, an inviscid surface exhibits mobile interfaces (e.g. soluble surfactants such as SDS). Thus, these surface flows are utilized to characterize the surface rheology of these complex interfaces.