Two Fluid Drop Snap-Off Problem: Experiments and Theory

We address the dynamics of a drop with viscosity $\lambda \eta$ breaking up inside another fluid of viscosity $\eta$. We track the time evolution of the drop near snap-off in the experiments and then compare with a scaling theory developed for $\lambda =1\mathrm{}$. The theory is in excellent agreement with both the experiments and the previous simulations of Lister and Stone. Finally, we also investigate the $\lambda$ dependence of the drop shape and breaking rate, and develop a simple theory for the latter.