Colloidal gel

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3D Reconstruction of a Colloidal Gel imaged using confocal microscopy

A colloidal gel is formed by introducing an attractive potential between dispersed colloidal particles. Depending on the strength of the attractive potential, gels can be formed even at arbitrarily low volume fractions. This gel has a finite elastic modulus and can resist shear stresses. Once the material begins to yield, it flows freely similar to a liquid. This property alone demonstrates a number of interesting characteristics exhibited by these materials.

Colloidal gels are fractals at distances lower than their correlation length, but appear homogeneous at larger length scales. Examining their structure reveals a network of interconnected colloidal strands.


References

  1. Dinsmore, A.D., Prasad, V., Wong, I.Y. & Weitz, D.A. "Microscopic Structure and Elasticity of Weakly Aggregated Colloidal Gels." Physical Review Letters, (2006), 96, 1885502-1 to 1885502-4.