Edinburgh Research Explorer

Dynamics of a colloid-stabilized cream

Research output: Contribution to journalArticle

  • E. M. Herzig
  • A. Robert
  • D. D. van't Zand
  • L. Cipelletti
  • P. N. Pusey
  • Paul Clegg

Related Edinburgh Organisations

Original languageEnglish
Article number011405
Pages (from-to)-
Number of pages7
JournalPhysical Review E - Statistical, Nonlinear and Soft Matter Physics
Volume79
Issue number1
DOIs
Publication statusPublished - Jan 2009

Abstract

We use x-ray photon correlation spectroscopy to investigate the dynamics of a high-volume-fraction emulsion creaming under gravity. The dodecane-in-water emulsion has interfaces stabilized solely by colloidal particles (silica). The samples were observed soon after mixing: as the emulsion becomes compact we discern two regimes of aging with a crossover between them. The young emulsion has faster dynamics associated with creaming in a crowded environment accompanied by local rearrangements. The dynamics slow down for the older emulsion, although our studies show that motion is associated with large intermittent events. The relaxation rate, as seen from the intensity autocorrelation function, depends linearly on the wave vector at all times; however, the exponent associated with the line shape changes from 1.5 for young samples to less than 1 as the emulsion ages. The combination of ballisticlike dynamics, an exponent that drops below 1, and large intermittent fluctuations has not been reported before to our knowledge.

    Research areas

  • colloids, emulsions, fluctuations, gravity, organic compounds, photon correlation spectroscopy, silicon compounds, transport processes, water, IN-WATER EMULSIONS, LIGHT-SCATTERING, SLOW DYNAMICS, SOFT MATTER, SPHERES, SEDIMENTATION, DIFFUSION, PARTICLES, TENSION, RANGE

ID: 1455944