Friday, 4 March 2011

Putting Acetone into Milk.

What happens when acetone is added to green dyed milk? Surface tension pulls and spreads dyed milk after acetone is dropped on the milk surface, illustrating the Marangoni effect.

The Marangoni effect (also called the Gibbs-Marangoni effect) is the mass transfer along an interface between two fluids due to the surface tension gradient. This phenomenon was first identified in the so called "tears of wine" and was studied by the physicist for his doctoral dissertation (of course he is Italian why not study wine). It can also be done if you spread some water on a smooth surface and then add some alcohol (like vodka) to the center. You will see that the liquid will rush out of the region where the drop fell. This is similarly shown to the picture above with milk and acetone.