THIS WORK IS FUNDED PRIMARILY BY: NSF grant CTS-0085751
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.
Our main interest is in the low shear rate dependence of the foams.
Under these conditions, the foam initially stretches elastically
until it reaches a critical value of the strain (or stress), known as the yield strain. At this point, it flows due to rearrangments of the
bubbles in the foam. We study both the distribution of stress drops and the bubble rearrangements. Movies of the foams can
be found in the picture section.
More details will appear as we continue our studies of the bubble rafts.