Coalescence & Spreading of Oil Drops on Water
What happens when a drop of oil gently lands on water? My MS research answered this with a systematic study of 11 oils — n-alkanes, polymers, and hydrocarbons spanning a wide range of viscosity and spreading coefficient. We showed that the coalescence outcome is set by the drop's Ohnesorge number and that early-time spreading is oscillatory before the film settles, deriving scaling laws that matched experiments with R² = 0.99. The physics matters wherever oil meets water: oil spill mitigation, pharmaceutical emulsions, and targeted drug delivery. Published in the Journal of Colloid & Interface Science.