As the heptane evaporated, as seen in Fig. , the hBN-stabilized water droplets began to spread. Eventually, as shown in Fig. , the droplets burst, revealing the hBN shells that had surrounded them. Some particles of unexfoliated hBN were present and appeared as dark spots. This morphology has also been shown for emulsions stabilized by graphene/graphite. Further evidence that the hBN surrounding the dispersed phase is a film of overlapping sheets, rather than simply the low aspect ratio particles found in typical Pickering emulsions, comes from electron microscopy. In Fig. , an SEM image of exfoliated hBN lifted from an oil: water interface shows hBN with micrometer scale lateral dimensions. The TEM image in Fig. indicates that the thickness of the hBN varies one to numerous layers of hBN. The image also demonstrates that hBN forms an overlapping film at the oil-water interface. There are regions with no hBN, regions with single sheets of hBN, and regions with stacked hBN. Additionally, some regions have moiré patterns, indicating that the hBN sheets exfoliated and restacked to form the film. These overlapping hBN films served to stabilize water-in-oil emulsions, and the size of the hBN flakes influenced the emulsion droplets' size. As shown by the acoustic spectroscopy results in Fig. , increasing the flake size of the hBN used to stabilize the emulsion increased the size of the emulsion droplets. In the case of the emulsions made with the same mass of hBN, changing from UK5 (5 µm) to UK10 (10 µm) hBN increased the average size of the dispersed drops from 19.7 to 45.2 µm. This increase is related to the stiffness of the hBN sheets, as smaller diameter spheres require the hBN sheets to bend more to adapt the sphere's curvature, an effect also seen with graphene. The total amount of hBN in the system also played a role in the size of the emulsion droplets. Adding less hBN meant less interfacial area could be stabilized, so encapsulating the same dispersed phase volume required larger spheres. This is shown graphically in Fig. , as well as in Table .