Highly nonlinear dynamics in a slowly sedimenting colloidal gel

Phys Rev Lett. 2011 Mar 18;106(11):118302. doi: 10.1103/PhysRevLett.106.118302. Epub 2011 Mar 14.

Abstract

We use a combination of original light scattering techniques and particles with unique optical properties to investigate the behavior of suspensions of attractive colloids under gravitational stress, following over time the concentration profile, the velocity profile, and the microscopic dynamics. During the compression regime, the sedimentation velocity grows nearly linearly with height, implying that the gel settling may be fully described by a (time-dependent) strain rate. We find that the microscopic dynamics exhibit remarkable scaling properties when time is normalized by the strain rate, showing that the gel microscopic restructuring is dominated by its macroscopic deformation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colloids / chemistry*
  • Gels / chemistry*
  • Gravitation*
  • Nonlinear Dynamics*
  • Particle Size
  • Scattering, Radiation
  • Suspensions / chemistry*
  • Time Factors

Substances

  • Colloids
  • Gels
  • Suspensions