(615e) Dynamics of Nucleation in 2D Monodisperse Oil-in-Water Emulsions

In encapsulated systems such as emulsions, crystalline droplets form at sufficiently low temperatures. Since nucleation is the earliest stage of liquid-crystal phase-transition, its dynamics impacts emulsion stability as well as their thermal and flow properties. Although nucleation in oil-in-water emulsions has been the subject of substantial investigations, the effect of factors such as droplet size, surfactants, solid surfaces, and droplet interactions are still unclear. Here, we visualize the in situ nucleation in an initially liquid 2D array of n-hexadecane-in-water droplets, generated by microfluidics, to see whether nucleation is history dependent. We monitor the number of crystalline droplets during the cooling of the 2D emulsion and determine the crystal fraction of the emulsion over time. We find that a smaller initial droplet size leads to a slower nucleation rate suggesting that the droplets crystallize via homogeneous nucleation. Additional results on the influence of surfactants and neighboring droplets on nucleation dynamics of emulsions will be reported.