Compressive yield stress of depletion gels from stationary centrifugation profiles

Abstract

By means of analytical centrifugation, we study the compression of colloidal gels where attractive forces between the particles are induced by a surfactant, acting as a depletion agent. The approximate pressure sustained by gels with different strength at different centrifugal acceleration is measured from the steady-state profiles of the transmitted intensity, using a conventional method. In the particular case in which the suspension is refractive-index–matched and the profile is directly related to the particle concentration, the equation of state of the gel can be obtained up to the random close-packing limit, highly extending current experimental and numerical data available.

Enrico Lattuada

Postdoctoral Researcher

Investigating the structure and dynamics of colloidal systems using optical techniques.