(541g) Drop Deformation and Spreading in Merger of an Oil Drop with an Immiscible Liquid Pool

Oil and water interactions form the basis of several every day scenarios such as salad dressings and emulsions for medication. To understand these interactions better one may isolate the dynamics of the impact of the single drop on a pool of liquid. Although literature is abundant on dynamics of high velocity droplet impact on liquid pools and films, gentle deposition of oil drops on a liquid pool has not been investigated in detail so far. In this work we address this process beginning with the topological transformations of the drop as it is brought close to the liquid pool and it eventual spreading as a liquid film. We see that the process proceeds in stages partially coalescing with every interaction. However, at higher droplet viscosity this ceases to exist, and we see complete merger. The time required for this to happen and the criterion determining when we observe partial and complete coalescence is established and correlated to liquid properties. Our work aims to shed light on oil-water interactions in three phase systems which have not received adequate attention in literature.