1. Emulsification separate phases, one water phase and one
oil phase. If you follow this return to two
Emulsification is the process of preparing separate phases closely you will notice that
emulsions, which are heterogeneous it starts with the joining of small droplets
systems consisting of at least one to form larger and larger ones.
immiscible liquid intimately dispersed in
another in the form of droplets. Interfacial A. Two immiscible liquids, not yet
tension also plays a important role emulsified.
in emulsification.
B. An emulsion of Phase II dispersed in
If two immiscible liquids are in contact Phase I.
with each other, they will tend to maintain
as small an interface as possible (as C. The unstable emulsion progressively
interfacial energy is associated with separates.
formation of any interfacial area).
Consequently, it is very difficult to mix the D. The surfactant (black outline) positions
two liquids. When they are shaken itself on the interfaces between Phase II
together, spherical droplets will form, as and Phase I, stabilizing the emulsion
the liquids tend to maintain as small a
surface area as possible and an interfacial
tension will be maintained between the two
liquids. When a “surface active” ingredient
is added, its molecules will tend to be
oriented between the two faces with the
polar ends in the polar phase and the non
polar ends in the non polar phase, which
will lower interfacial tension. This will
result in miscibility of the two liquids.
Consider what happens when you prepare
a salad dressing. You basically mix oil,
water and herbs. When you shake this
mixture a lot of small droplets of oil are
formed and suspended in the water. If you
have done your shaking well the
suspension will last for some time, but will
eventually go back to the state with two
Compiled by Deniz Kaya -1-