Elasticity of Compressed Emulsions.

The elastic shear modulus of monodisperse emulsions is shown to exhibit a universal dependence on droplet volume fraction f when scaled by the Laplace pressure of the droplets, increasing as fsf 2 fcd, where fc ø 0.635, the value of random close packing of solid spheres. Surprisingly the osmotic pressure required to compress the emulsions to increase f is nearly the same as the shear modulus over a large range of volume fraction, while the bulk osmotic modulus differs significantly. Models based on the structural disorder of the emulsions are discussed to account for these data.