Noncoalescing drops - art. no. 206104

A pure water drop coalesces almost immediately with a pure water surface. M inute amounts of surfactant can alter this process dramatically. When the d rop is released towards the surface of the solution from a certain height s maller than a well defined critical height, the drop of surfactant solution either remains on the surface for a specific time or coalesces immediately . The statistics of the residence time are systematically measured along wi th the critical heights necessary for coalescence. It turns out that the su rface elasticity controls coalescence in such a situation.