  Emulsion Stability Simulations (ESS) are used to estimate the coalescence
time of one drop of hexadecane pressed by buoyancy against a planar
water/hexadecane interface. In the present simulations the homophase is
represented by a big drop of oil at least 500 times larger than the approaching
drop ($1\,\mu$m to $10\,\mu$m). Both deformable and non-deformable drops are
considered along with six different diffusion tensors. In each case van der
Waals, electrostatic, steric and buoyancy forces are taken into account. The
coalescence times are estimated as the average of 1000 random walks. It is
found that the repulsive potential barrier has a significant influence in the
results. The experimental data can only be reproduced assuming negligible
repulsive barriers, as well as non-deformable drops that move with a
combination of Stokes and Taylor tensors as they approach the interface.
