%0 Journal Article %J European Physical Journal E %D 2009 %T Gravitational compression of colloidal gels %A Lietor-Santos, J. J. %A Kim, C. %A Lu, P. J. %A Fernandez-Nieves, A. %A Weitz, D. A. %X We study the compression of depletion gels under the influence of a gravitational stress by monitoring the time evolution of the gel interface and the local volume fraction, phi, inside the gel. We find f is not constant throughout the gel. Instead, there is a volume fraction gradient that develops and grows along the gel height as the compression process proceeds. Our results are correctly described by a non-linear poroelastic model that explicitly incorporates the phi-dependence of the gravitational, elastic and viscous stresses acting on the gel. %B European Physical Journal E %V 28 %P 159-164 %G eng %U https://link.springer.com/article/10.1140%2Fepje%2Fi2008-10390-7