The reluctance of these two liquids

to mix together and stay that way is so well known they

have become cliche for any two things

that do not go together well.

Currently, there are ways to mix the two,

but ultimately, they will separate again.

So what if there was a way to not only mix oil and water,

but to have the mixture remain stable

for long periods of time, perhaps indefinitely?

Well, a team of researchers at MIT

may have found a way to do just that.

Here we have oil and water represented

by the colors red and blue.

Alone, these two liquids will not mix together.

But add in a soap-like substance,

called a surfactant, then mix, and suddenly, the two liquids

will blend.

This type of mixture of two or more liquids

that are normally immiscible is called an emulsion.

Now, creating emulsions is not a new process.

Think of the mixture of oil and vinegar in salad dressings,

for example.

But the challenge is to get the emulsions

to remain stable for longer than a few minutes.

The key to overcoming ultimate separation

is to have really small, nano-sized droplets.

When the drops are that small, gravity cannot overcome them,

and they can remain suspended indefinitely.

There are ways to do this.

However, the current industrial processes

are extremely energy intensive and expensive.

The new process used in the MIT lab

requires very little energy, in fact, no mixing at all,

and can remain stable for months.

This new process takes a bottom-up approach

by using condensation to create the droplets.

First, they take a reservoir of oil with an added surfactant,

place it inside a chamber with very humid air,

and cool the oil.

As it cools, the condensing water

forms droplets at the surface that

spread through the oil-surfactant mixture,

forming uniform, nanoscale droplets.

These droplets are so tiny and uniformed that they

are hard to even see under a microscope.

The team believes the approach should

work with a variety of oils and surfactants.

This new process could provide design guidelines for use

in particular applications that have

expiration dates, like drug delivery, cosmetics,

and processed foods.