Forming Emulsions: Overcoming the Force
of Surface Tension It takes work to make an
emulsion. We all know from experience that
when we pour water and oil into the same
bowl, they form two separate layers: one
doesn’t just turn into tiny droplets and invade
the other. The reason for this behavior is that
when liquids can’t mix for chemical reasons,
they spontaneously arrange themselves in a
way that minimizes their contact with each
other. They form a single large mass, which
exposes less surface area to the other liquid
than does the same total mass broken into
pieces. This tendency of liquids to minimize
their surface area is an expression of the force
called surface tension.
Mayonnaise formation. Two stages in making
mayonnaise as seen through a light
microscope. One tablespoon/15 ml of oil