Janus Emulsions of Bertholletia Excelsa Oil and Silicone Oil

Janus emulsions of Bertholletia Excelsa oil and silicone oil in water were prepared in batch by high energy emulsification and their destabilization studied by observing the creaming and final separation of the two oils. The creaming was shown to be characteristic of a flocculated emulsion in accordance with the optical microscope image of a concentrated emulsion, but with few drop-drop contacts. During the creaming process the Janus drops suffered coalescence, but retained the Janus topology till the final stage after more than a month of storage, at which time the two oils set off separation into two bulk liquids. The unexpected stability of the topology per se indicated a more general importance of Janus emulsions than hitherto recognized and prompted a calculation to compare the relative free energy reduction during the coalescence versus the increase during the separation of the two oils. The latter energy change was significantly superior and was concluded to be an essential factor for the stability of the Janus topology.