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Updated: May 17, 2026

Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
Depletion induced clustering in mixtures of colloidal spheres and fd-virus
D Guu1, J K G Dhont, G A Vliegenthart
1Institute of Complex Systems, Forschungszentrum Jülich, D-52425 Jülich, Germany.
Abstract:
We determined the phase boundary of an ideal rod-sphere mixture consisting of fd-virus, which is an established model system for mono-disperse colloidal rods, and density matched mono-disperse polystyrene beads employing diffuse wave spectroscopy. The low volume fraction of fd needed to induce a phase separation at relatively low ionic strength exemplifies the fact that slender rods are very effective depletion agents. Confocal microscopy showed that stable clusters are formed during phase separation. Relaxation after shear deformation of these clusters showed that the phase separation is gas-liquid-like and that the interfacial tension involved is very low as in colloid-polymer mixtures.
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