with additional support from Research Corporation and the Sloan Foundation.

Our work on two-dimensional foams focuses on two systems: bubble rafts and monolayer foams. For a brief introduction to monolayers, see our monolayer page.

For the monolayer foams, the foam consists of "bubbles" of the gas phase and "walls" of the liquid phase. The foam is imaged using fluorescence microscopy - so the walls appear bright.

For the bubble rafts, a single layer of bubbles is place in our Couette trough. An image of this is shown here. The bubbles in this image are on the order of 1 mm in size.


We also study foams in a parallel geometry. More recently, we have begun work on plastic beads that are confined to the air-water interface.

Movies of the foams can be found in the picture section.

Some of the issues that we study include:

a) The role of topological rearrangements of the bubbles and sudden releases of stress in the flow behavior of the material.
b) The impact of applied stresses on the order/disorder of the material.
c) The connection between the microscopic properties (surfactant additives and other components of the foam), the mesoscopic structure (bubble topology), and the macroscopic response.
d) The role of dislocations in a model crystal (hexagonal bubble raft of monodisperse bubbles) under stress.
e) Ideas of effective temperatures and jamming phase diagrams as a unifying principle that provides a deeper understanding of many complex fluids.

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