2022 Annual Meeting
Emulsion Dynamics in Microgravity By Diffusing Wave Spectroscopy
Emulsions are ubiquitous in food, pharmaceuticals, and consumer products. An emulsion is a multiphase mixture of immiscible fluids with dispersed droplets. For macroemulsions studied in this experiment, droplet sizes are between 0.5um and 10um. On Earth, emulsions are largely dominated by body forces such as gravity. The gravitational force is more significant on larger droplets. Under microgravity conditions, body forces no longer dominate the system . Microgravity is achieved by running experiments aboard the International Space Station (ISS). In these conditions, other important phenomena, such as coalescence and flocculation can be studied in isolation. We are measuring the rate of destabilization of an emulsion. We focus on understanding the effects of surfactant concentration, the volume fraction of the dispersed phase, and the choice of surfactant on the stability of an emulsion using Diffusing Wave Spectroscopy (DWS). DWS probes system dynamics using photons, allowing for an analysis of droplet size and type of motion characterizing drop behavior. We discuss trends in surfactant concentration and impact of surfactant concentration on the rate of emulsion destabilization.