Foam is where the heart is

Foam is not only important in today's cafe-bar society, for making cappuccinos and giving beer an attractive head, but it is also vital to industry. Foams are used to separate mineral ore from crushed rock and for enhanced oil recovery to extract the final reserves from near-depleted oil wells. So anything that improves our use of foam can produce economic benefits.

That's why Dr Simon Cox of the

will spend the next five years getting a better understanding of how foams flow. He will develop computer models of foams, and compare their predictions with experiment results, to pin down the important elements of the way that it flows. Companies such as Unilever are interested in better foams for personal care products, or for manufactured foods such as mousses.

'Aqueous foams are complex fluids whose properties lie between the familiar extremes of liquid and solid,' said Cox. 'For small strains a foam behaves as an elastic solid while at large strains a foam moves like a liquid. So they generate a rich range of behaviours, but with a well-defined local structure.'